Gut microbiota of healthy Canadian infants: profiles by mode of delivery and infant diet at 4 months

Background:

The gut microbiota is essential to human health throughout life, yet the acquisition and development of this microbial community during infancy remains poorly understood. Meanwhile, there is increasing concern over rising rates of cesarean delivery and insufficient exclusive breastfeeding of infants in developed countries. In this article, we characterize the gut microbiota of healthy Canadian infants and describe the influence of cesarean delivery and formula feeding.

Methods:

We included a subset of 24 term infants from the Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort. Mode of delivery was obtained from medical records, and mothers were asked to report on infant diet and medication use. Fecal samples were collected at 4 months of age, and we characterized the microbiota composition using high-throughput DNA sequencing.

Results:

We observed high variability in the profiles of fecal microbiota among the infants. The profiles were generally dominated by Actinobacteria (mainly the genus Bifidobacterium) and Firmicutes (with diverse representation from numerous genera). Compared with breastfed infants, formula-fed infants had increased richness of species, with overrepresentation of Clostridium difficile. Escherichia–Shigella and Bacteroides species were underrepresented in infants born by cesarean delivery. Infants born by elective cesarean delivery had particularly low bacterial richness and diversity.

Interpretation:

These findings advance our understanding of the gut microbiota in healthy infants. They also provide new evidence for the effects of delivery mode and infant diet as determinants of this essential microbial community in early life.The human body harbours trillions of microbes, known collectively as the “human microbiome.” By far the highest density of commensal bacteria is found in the digestive tract, where resident microbes outnumber host cells by at least 10 to 1. Gut bacteria play a fundamental role in human health by promoting intestinal homeostasis, stimulating development of the immune system, providing protection against pathogens, and contributing to the processing of nutrients and harvesting of energy.^1,2 The disruption of the gut microbiota has been linked to an increasing number of diseases, including inflammatory bowel disease, necrotizing enterocolitis, diabetes, obesity, cancer, allergies and asthma.¹ Despite this evidence and a growing appreciation for the integral role of the gut microbiota in lifelong health, relatively little is known about the acquisition and development of this complex microbial community during infancy.³Two of the best-studied determinants of the gut microbiota during infancy are mode of delivery and exposure to breast milk.^4,5 Cesarean delivery perturbs normal colonization of the infant gut by preventing exposure to maternal microbes, whereas breastfeeding promotes a “healthy” gut microbiota by providing selective metabolic substrates for beneficial bacteria.^3,5 Despite recommendations from the World Health Organization,⁶ the rate of cesarean delivery has continued to rise in developed countries and rates of breastfeeding decrease substantially within the first few months of life.^7,8 In Canada, more than 1 in 4 newborns are born by cesarean delivery, and less than 15% of infants are exclusively breastfed for the recommended duration of 6 months.^9,10 In some parts of the world, elective cesarean deliveries are performed by maternal request, often because of apprehension about pain during childbirth, and sometimes for patient–physician convenience.¹¹The potential long-term consequences of decisions regarding mode of delivery and infant diet are not to be underestimated. Infants born by cesarean delivery are at increased risk of asthma, obesity and type 1 diabetes,¹² whereas breastfeeding is variably protective against these and other disorders.¹³ These long-term health consequences may be partially attributable to disruption of the gut microbiota.^12,14Historically, the gut microbiota has been studied with the use of culture-based methodologies to examine individual organisms. However, up to 80% of intestinal microbes cannot be grown in culture.^3,15 New technology using culture-independent DNA sequencing enables comprehensive detection of intestinal microbes and permits simultaneous characterization of entire microbial communities. Multinational consortia have been established to characterize the “normal” adult microbiome using these exciting new methods;¹⁶ however, these methods have been underused in infant studies. Because early colonization may have long-lasting effects on health, infant studies are vital.^3,4 Among the few studies of infant gut microbiota using DNA sequencing, most were conducted in restricted populations, such as infants delivered vaginally,¹⁷ infants born by cesarean delivery who were formula-fed¹⁸ or preterm infants with necrotizing enterocolitis.¹⁹Thus, the gut microbiota is essential to human health, yet the acquisition and development of this microbial community during infancy remains poorly understood.³ In the current study, we address this gap in knowledge using new sequencing technology and detailed exposure assessments²⁰ of healthy Canadian infants selected from a national birth cohort to provide representative, comprehensive profiles of gut microbiota according to mode of delivery and infant diet.     

Effectiveness of interventions designed to reduce the use of imaging for low-back pain: a systematic review

Background:Rates of imaging for low-back pain are high and are associated with increased health care costs and radiation exposure as well as potentially poorer patient outcomes. We conducted a systematic review to investigate the effectiveness of interventions aimed at reducing the use of imaging for low-back pain.Methods:We searched MEDLINE, Embase, CINAHL and the Cochrane Central Register of Controlled Trials from the earliest records to June 23, 2014. We included randomized controlled trials, controlled clinical trials and interrupted time series studies that assessed interventions designed to reduce the use of imaging in any clinical setting, including primary, emergency and specialist care. Two independent reviewers extracted data and assessed risk of bias. We used raw data on imaging rates to calculate summary statistics. Study heterogeneity prevented meta-analysis.Results:A total of 8500 records were identified through the literature search. Of the 54 potentially eligible studies reviewed in full, 7 were included in our review. Clinical decision support involving a modified referral form in a hospital setting reduced imaging by 36.8% (95% confidence interval [CI] 33.2% to 40.5%). Targeted reminders to primary care physicians of appropriate indications for imaging reduced referrals for imaging by 22.5% (95% CI 8.4% to 36.8%). Interventions that used practitioner audits and feedback, practitioner education or guideline dissemination did not significantly reduce imaging rates. Lack of power within some of the included studies resulted in lack of statistical significance despite potentially clinically important effects.Interpretation:Clinical decision support in a hospital setting and targeted reminders to primary care doctors were effective interventions in reducing the use of imaging for low-back pain. These are potentially low-cost interventions that would substantially decrease medical expenditures associated with the management of low-back pain.Current evidence-based clinical practice guidelines recommend against the routine use of imaging in patients presenting with low-back pain.^1–3 Despite this, imaging rates remain high,^4,5 which indicates poor concordance with these guidelines.^6,7Unnecessary imaging for low-back pain has been associated with poorer patient outcomes, increased radiation exposure and higher health care costs.⁸ No short- or long-term clinical benefits have been shown with routine imaging of the low back, and the diagnostic value of incidental imaging findings remains uncertain.^9–12 A 2008 systematic review found that imaging accounted for 7% of direct costs associated with low-back pain, which in 1998 translated to more than US$6 billion in the United States and £114 million in the United Kingdom.¹³ Current costs are likely to be substantially higher, with an estimated 65% increase in spine-related expenditures between 1997 and 2005.¹⁴Various interventions have been tried for reducing imaging rates among people with low-back pain. These include strategies targeted at the practitioner such as guideline dissemination,^15–17 education workshops,^18,19 audit and feedback of imaging use,^7,20,21 ongoing reminders⁷ and clinical decision support.^22–24 It is unclear which, if any, of these strategies are effective.²⁵ We conducted a systematic review to investigate the effectiveness of interventions designed to reduce imaging rates for the management of low-back pain.     

A qualitative investigation of smoke-free policies on hospital property

Background:

Many hospitals have adopted smoke-free policies on their property. We examined the consequences of such polices at two Canadian tertiary acute-care hospitals.

Methods:

We conducted a qualitative study using ethnographic techniques over a six-month period. Participants (n = 186) shared their perspectives on and experiences with tobacco dependence and managing the use of tobacco, as well as their impressions of the smoke-free policy. We interviewed inpatients individually from eight wards (n = 82), key policy-makers (n = 9) and support staff (n = 14) and held 16 focus groups with health care providers and ward staff (n = 81). We also reviewed ward documents relating to tobacco dependence and looked at smoking-related activities on hospital property.

Results:

Noncompliance with the policy and exposure to secondhand smoke were ongoing concerns. Peoples’ impressions of the use of tobacco varied, including divergent opinions as to whether such use was a bad habit or an addiction. Treatment for tobacco dependence and the management of symptoms of withdrawal were offered inconsistently. Participants voiced concerns over patient safety and leaving the ward to smoke.

Interpretation:

Policies mandating smoke-free hospital property have important consequences beyond noncompliance, including concerns over patient safety and disruptions to care. Without adequately available and accessible support for withdrawal from tobacco, patients will continue to face personal risk when they leave hospital property to smoke.Canadian cities and provinces have passed smoking bans with the goal of reducing people’s exposure to secondhand smoke in workplaces, public spaces and on the property adjacent to public buildings.^1,2 In response, Canadian health authorities and hospitals began implementing policies mandating smoke-free hospital property, with the goals of reducing the exposure of workers, patients and visitors to tobacco smoke while delivering a public health message about the dangers of smoking.^2–5 An additional anticipated outcome was the reduced use of tobacco among patients and staff. The impetuses for adopting smoke-free policies include public support for such legislation and the potential for litigation for exposure to second-hand smoke.^2,4Tobacco use is a modifiable risk factor associated with a variety of cancers, cardiovascular diseases and respiratory conditions.^6–11 Patients in hospital who use tobacco tend to have more surgical complications and exacerbations of acute and chronic health conditions than patients who do not use tobacco.^6–11 Any policy aimed at reducing exposure to tobacco in hospitals is well supported by evidence, as is the integration of interventions targetting tobacco dependence.¹² Unfortunately, most of the nearly five million Canadians who smoke will receive suboptimal treatment,¹³ as the routine provision of interventions for tobacco dependence in hospital settings is not a practice norm.^14–16 In smoke-free hospitals, two studies suggest minimal support is offered for withdrawal, ^17,18 and one reports an increased use of nicotine-replacement therapy after the implementation of the smoke-free policy.¹⁹Assessments of the effectiveness of smoke-free policies for hospital property tend to focus on noncompliance and related issues of enforcement.^17,20,21 Although evidence of noncompliance and litter on hospital property^2,17,20 implies ongoing exposure to tobacco smoke, half of the participating hospital sites in one study reported less exposure to tobacco smoke within hospital buildings and on the property.¹⁸ In addition, there is evidence to suggest some decline in smoking among staff.^18,19,21,22We sought to determine the consequences of policies mandating smoke-free hospital property in two Canadian acute-care hospitals by eliciting lived experiences of the people faced with enacting the policies: patients and health care providers. In addition, we elicited stories from hospital support staff and administrators regarding the policies.     

Effect of ambient air pollution on the incidence of appendicitis

Background

The pathogenesis of appendicitis is unclear. We evaluated whether exposure to air pollution was associated with an increased incidence of appendicitis.

Methods

We identified 5191 adults who had been admitted to hospital with appendicitis between Apr. 1, 1999, and Dec. 31, 2006. The air pollutants studied were ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, and suspended particulate matter of less than 10 μ and less than 2.5 μ in diameter. We estimated the odds of appendicitis relative to short-term increases in concentrations of selected pollutants, alone and in combination, after controlling for temperature and relative humidity as well as the effects of age, sex and season.

Results

An increase in the interquartile range of the 5-day average of ozone was associated with appendicitis (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.03–1.25). In summer (July–August), the effects were most pronounced for ozone (OR 1.32, 95% CI 1.10–1.57), sulfur dioxide (OR 1.30, 95% CI 1.03–1.63), nitrogen dioxide (OR 1.76, 95% CI 1.20–2.58), carbon monoxide (OR 1.35, 95% CI 1.01–1.80) and particulate matter less than 10 μ in diameter (OR 1.20, 95% CI 1.05–1.38). We observed a significant effect of the air pollutants in the summer months among men but not among women (e.g., OR for increase in the 5-day average of nitrogen dioxide 2.05, 95% CI 1.21–3.47, among men and 1.48, 95% CI 0.85–2.59, among women). The double-pollutant model of exposure to ozone and nitrogen dioxide in the summer months was associated with attenuation of the effects of ozone (OR 1.22, 95% CI 1.01–1.48) and nitrogen dioxide (OR 1.48, 95% CI 0.97–2.24).

Interpretation

Our findings suggest that some cases of appendicitis may be triggered by short-term exposure to air pollution. If these findings are confirmed, measures to improve air quality may help to decrease rates of appendicitis.Appendicitis was introduced into the medical vernacular in 1886.¹ Since then, the prevailing theory of its pathogenesis implicated an obstruction of the appendiceal orifice by a fecalith or lymphoid hyperplasia.² However, this notion does not completely account for variations in incidence observed by age,^3,4 sex,^3,4 ethnic background,^3,4 family history,⁵ temporal–spatial clustering⁶ and seasonality,^3,4 nor does it completely explain the trends in incidence of appendicitis in developed and developing nations.^3,7,8The incidence of appendicitis increased dramatically in industrialized nations in the 19th century and in the early part of the 20th century.¹ Without explanation, it decreased in the middle and latter part of the 20th century.³ The decrease coincided with legislation to improve air quality. For example, after the United States Clean Air Act was passed in 1970,⁹ the incidence of appendicitis decreased by 14.6% from 1970 to 1984.³ Likewise, a 36% drop in incidence was reported in the United Kingdom between 1975 and 1994¹⁰ after legislation was passed in 1956 and 1968 to improve air quality and in the 1970s to control industrial sources of air pollution. Furthermore, appendicitis is less common in developing nations; however, as these countries become more industrialized, the incidence of appendicitis has been increasing.⁷Air pollution is known to be a risk factor for multiple conditions, to exacerbate disease states and to increase all-cause mortality.¹¹ It has a direct effect on pulmonary diseases such as asthma¹¹ and on nonpulmonary diseases including myocardial infarction, stroke and cancer.^11–13 Inflammation induced by exposure to air pollution contributes to some adverse health effects.^14–17 Similar to the effects of air pollution, a proinflammatory response has been associated with appendicitis.^18–20We conducted a case–crossover study involving a population-based cohort of patients admitted to hospital with appendicitis to determine whether short-term increases in concentrations of selected air pollutants were associated with hospital admission because of appendicitis.     

Relation between fractures and mortality: results from the Canadian Multicentre Osteoporosis Study

Background

Fractures have largely been assessed by their impact on quality of life or health care costs. We conducted this study to evaluate the relation between fractures and mortality.

Methods

A total of 7753 randomly selected people (2187 men and 5566 women) aged 50 years and older from across Canada participated in a 5-year observational cohort study. Incident fractures were identified on the basis of validated self-report and were classified by type (vertebral, pelvic, forearm or wrist, rib, hip and “other”). We subdivided fracture groups by the year in which the fracture occurred during follow-up; those occurring in the fourth and fifth years were grouped together. We examined the relation between the time of the incident fracture and death.

Results

Compared with participants who had no fracture during follow-up, those who had a vertebral fracture in the second year were at increased risk of death (adjusted hazard ratio [HR] 2.7, 95% confidence interval [CI] 1.1–6.6); also at risk were those who had a hip fracture during the first year (adjusted HR 3.2, 95% CI 1.4–7.4). Among women, the risk of death was increased for those with a vertebral fracture during the first year (adjusted HR 3.7, 95% CI 1.1–12.8) or the second year of follow-up (adjusted HR 3.2, 95% CI 1.2–8.1). The risk of death was also increased among women with hip fracture during the first year of follow-up (adjusted HR 3.0, 95% CI 1.0–8.7).

Interpretation

Vertebral and hip fractures are associated with an increased risk of death. Interventions that reduce the incidence of these fractures need to be implemented to improve survival.Osteoporosis-related fractures are a major health concern, affecting a growing number of individuals worldwide. The burden of fracture has largely been assessed by the impact on health-related quality of life and health care costs.^1,2 Fractures can also be associated with death. However, trials that have examined the relation between fractures and mortality have had limitations that may influence their results and the generalizability of the studies, including small samples,^3,4 the examination of only 1 type of fracture,^4–10 the inclusion of only women,^8,11 the enrolment of participants from specific areas (i.e., hospitals or certain geographic regions),^{3,4,7,8,10,12} the nonrandom selection of participants^3–11 and the lack of statistical adjustment for confounding factors that may influence mortality.^3,5–7,12We evaluated the relation between incident fractures and mortality over a 5-year period in a cohort of men and women 50 years of age and older. In addition, we examined whether other characteristics of participants were risk factors for death.     

Risk of vascular events in patients with polymyalgia rheumatica

Background:

Polymyalgia rheumatica is one of the most common inflammatory rheumatologic conditions in older adults. Other inflammatory rheumatologic disorders are associated with an excess risk of vascular disease. We investigated whether polymyalgia rheumatica is associated with an increased risk of vascular events.

Methods:

We used the General Practice Research Database to identify patients with a diagnosis of incident polymyalgia rheumatica between Jan. 1, 1987, and Dec. 31, 1999. Patients were matched by age, sex and practice with up to 5 patients without polymyalgia rheumatica. Patients were followed until their first vascular event (cardiovascular, cerebrovascular, peripheral vascular) or the end of available records (May 2011). All participants were free of vascular disease before the diagnosis of polymyalgia rheumatica (or matched date). We used Cox regression models to compare time to first vascular event in patients with and without polymyalgia rheumatica.

Results:

A total of 3249 patients with polymyalgia rheumatica and 12 735 patients without were included in the final sample. Over a median follow-up period of 7.8 (interquartile range 3.3–12.4) years, the rate of vascular events was higher among patients with polymyalgia rheumatica than among those without (36.1 v. 12.2 per 1000 person-years; adjusted hazard ratio 2.6, 95% confidence interval 2.4–2.9). The increased risk of a vascular event was similar for each vascular disease end point. The magnitude of risk was higher in early disease and in patients younger than 60 years at diagnosis.

Interpretation:

Patients with polymyalgia rheumatica have an increased risk of vascular events. This risk is greatest in the youngest age groups. As with other forms of inflammatory arthritis, patients with polymyalgia rheumatica should have their vascular risk factors identified and actively managed to reduce this excess risk.Inflammatory rheumatologic disorders such as rheumatoid arthritis,^1,2 systemic lupus erythematosus,^2,3 gout,⁴ psoriatic arthritis^2,5 and ankylosing spondylitis^2,6 are associated with an increased risk of vascular disease, especially cardiovascular disease, leading to substantial morbidity and premature death.^2–6 Recognition of this excess vascular risk has led to management guidelines advocating screening for and management of vascular risk factors.^7–9Polymyalgia rheumatica is one of the most common inflammatory rheumatologic conditions in older adults,¹⁰ with a lifetime risk of 2.4% for women and 1.7% for men.¹¹ To date, evidence regarding the risk of vascular disease in patients with polymyalgia rheumatica is unclear. There are a number of biologically plausible mechanisms between polymyalgia rheumatica and vascular disease. These include the inflammatory burden of the disease,^12,13 the association of the disease with giant cell arteritis (causing an inflammatory vasculopathy, which may lead to subclinical arteritis, stenosis or aneurysms),¹⁴ and the adverse effects of long-term corticosteroid treatment (e.g., diabetes, hypertension and dyslipidemia).^15,16 Paradoxically, however, use of corticosteroids in patients with polymyalgia rheumatica may actually decrease vascular risk by controlling inflammation.¹⁷ A recent systematic review concluded that although some evidence exists to support an association between vascular disease and polymyalgia rheumatica,¹⁸ the existing literature presents conflicting results, with some studies reporting an excess risk of vascular disease^19,20 and vascular death,^21,22 and others reporting no association.^23–26 Most current studies are limited by poor methodologic quality and small samples, and are based on secondary care cohorts, who may have more severe disease, yet most patients with polymyalgia rheumatica receive treatment exclusively in primary care.²⁷The General Practice Research Database (GPRD), based in the United Kingdom, is a large electronic system for primary care records. It has been used as a data source for previous studies,²⁸ including studies on the association of inflammatory conditions with vascular disease²⁹ and on the epidemiology of polymyalgia rheumatica in the UK.³⁰ The aim of the current study was to examine the association between polymyalgia rheumatica and vascular disease in a primary care population.     

Effect of nasal balloon autoinflation in children with otitis media with effusion in primary care: an open randomized controlled trial

Background:Otitis media with effusion is a common problem that lacks an evidence-based nonsurgical treatment option. We assessed the clinical effectiveness of treatment with a nasal balloon device in a primary care setting.Methods:We conducted an open, pragmatic randomized controlled trial set in 43 family practices in the United Kingdom. Children aged 4–11 years with a recent history of ear symptoms and otitis media with effusion in 1 or both ears, confirmed by tympanometry, were allocated to receive either autoinflation 3 times daily for 1–3 months plus usual care or usual care alone. Clearance of middle-ear fluid at 1 and 3 months was assessed by experts masked to allocation.Results:Of 320 children enrolled, those receiving autoinflation were more likely than controls to have normal tympanograms at 1 month (47.3% [62/131] v. 35.6% [47/132]; adjusted relative risk [RR] 1.36, 95% confidence interval [CI] 0.99 to 1.88) and at 3 months (49.6% [62/125] v. 38.3% [46/120]; adjusted RR 1.37, 95% CI 1.03 to 1.83; number needed to treat = 9). Autoinflation produced greater improvements in ear-related quality of life (adjusted between-group difference in change from baseline in OMQ-14 [an ear-related measure of quality of life] score −0.42, 95% CI −0.63 to −0.22). Compliance was 89% at 1 month and 80% at 3 months. Adverse events were mild, infrequent and comparable between groups.Interpretation:Autoinflation in children aged 4–11 years with otitis media with effusion is feasible in primary care and effective both in clearing effusions and improving symptoms and ear-related child and parent quality of life. Trial registration: ISRCTN, No. 55208702.Otitis media with effusion, also known as glue ear, is an accumulation of fluid in the middle ear, without symptoms or signs of an acute ear infection. It is often associated with viral infection.^1–3 The prevalence rises to 46% in children aged 4–5 years,⁴ when hearing difficulty, other ear-related symptoms and broader developmental concerns often bring the condition to medical attention.^3,5,6 Middle-ear fluid is associated with conductive hearing losses of about 15–45 dB HL.⁷ Resolution is clinically unpredictable,^8–10 with about a third of cases showing recurrence.¹¹ In the United Kingdom, about 200 000 children with the condition are seen annually in primary care.^12,13 Research suggests some children seen in primary care are as badly affected as those seen in hospital.^7,9,14,15 In the United States, there were 2.2 million diagnosed episodes in 2004, costing an estimated $4.0 billion.¹⁶ Rates of ventilation tube surgery show variability between countries,^17–19 with a declining trend in the UK.²⁰Initial clinical management consists of reasonable temporizing or delay before considering surgery.¹³ Unfortunately, all available medical treatments for otitis media with effusion such as antibiotics, antihistamines, decongestants and intranasal steroids are ineffective and have unwanted effects, and therefore cannot be recommended.^21–23 Not only are antibiotics ineffective, but resistance to them poses a major threat to public health.^24,25 Although surgery is effective for a carefully selected minority,^13,26,27 a simple low-cost, nonsurgical treatment option could benefit a much larger group of symptomatic children, with the purpose of addressing legitimate clinical concerns without incurring excessive delays.Autoinflation using a nasal balloon device is a low-cost intervention with the potential to be used more widely in primary care, but current evidence of its effectiveness is limited to several small hospital-based trials²⁸ that found a higher rate of tympanometric resolution of ear fluid at 1 month.^29–31 Evidence of feasibility and effectiveness of autoinflation to inform wider clinical use is lacking.^13,28 Thus we report here the findings of a large pragmatic trial of the clinical effectiveness of nasal balloon autoinflation in a spectrum of children with clinically confirmed otitis media with effusion identified from primary care.     

Prevalence of and risk factors for persistent postoperative nonanginal pain after cardiac surgery: a 2-year prospective multicentre study

Background:

Persistent postoperative pain continues to be an underrecognized complication. We examined the prevalence of and risk factors for this type of pain after cardiac surgery.

Methods:

We enrolled patients scheduled for coronary artery bypass grafting or valve replacement, or both, from Feb. 8, 2005, to Sept. 1, 2009. Validated measures were used to assess (a) preoperative anxiety and depression, tendency to catastrophize in the face of pain, health-related quality of life and presence of persistent pain; (b) pain intensity and interference in the first postoperative week; and (c) presence and intensity of persistent postoperative pain at 3, 6, 12 and 24 months after surgery. The primary outcome was the presence of persistent postoperative pain during 24 months of follow-up.

Results:

A total of 1247 patients completed the preoperative assessment. Follow-up retention rates at 3 and 24 months were 84% and 78%, respectively. The prevalence of persistent postoperative pain decreased significantly over time, from 40.1% at 3 months to 22.1% at 6 months, 16.5% at 12 months and 9.5% at 24 months; the pain was rated as moderate to severe in 3.6% at 24 months. Acute postoperative pain predicted both the presence and severity of persistent postoperative pain. The more intense the pain during the first week after surgery and the more it interfered with functioning, the more likely the patients were to report persistent postoperative pain. Pre-existing persistent pain and increased preoperative anxiety also predicted the presence of persistent postoperative pain.

Interpretation:

Persistent postoperative pain of nonanginal origin after cardiac surgery affected a substantial proportion of the study population. Future research is needed to determine whether interventions to modify certain risk factors, such as preoperative anxiety and the severity of pain before and immediately after surgery, may help to minimize or prevent persistent postoperative pain.Postoperative pain that persists beyond the normal time for tissue healing (> 3 mo) is increasingly recognized as an important complication after various types of surgery and can have serious consequences on patients’ daily living.^1–3 Cardiac surgeries, such as coronary artery bypass grafting (CABG) and valve replacement, rank among the most frequently performed interventions worldwide.⁴ They aim to improve survival and quality of life by reducing symptoms, including anginal pain. However, persistent postoperative pain of nonanginal origin has been reported in 7% to 60% of patients following these surgeries.^5–23 Such variability is common in other types of major surgery and is due mainly to differences in the definition of persistent postoperative pain, study design, data collection methods and duration of follow-up.^1–3,24Few prospective cohort studies have examined the exact time course of persistent postoperative pain after cardiac surgery, and follow-up has always been limited to a year or less.^9,14,25 Factors that put patients at risk of this type of problem are poorly understood.²⁶ Studies have reported inconsistent results regarding the contribution of age, sex, body mass index, preoperative angina, surgical technique, grafting site, postoperative complications or level of opioid consumption after surgery.^{5–7,9,13,14,16–19,21–23,25,27} Only 1 study investigated the role of chronic nonanginal pain before surgery as a contributing factor;²¹ 5 others prospectively assessed the association between persistent postoperative pain and acute pain intensity in the first postoperative week but reported conflicting results.^{13,14,21,22,25} All of the above studies were carried out in a single hospital and included relatively small samples. None of the studies examined the contribution of psychological factors such as levels of anxiety and depression before cardiac surgery, although these factors have been shown to influence acute or persistent postoperative pain in other types of surgery.^1,24,28,29We conducted a prospective multicentre cohort study (the CARD-PAIN study) to determine the prevalence of persistent postoperative pain of nonanginal origin up to 24 months after cardiac surgery and to identify risk factors for the presence and severity of the condition.     

Mediterranean diets and metabolic syndrome status in the PREDIMED randomized trial

Background:

Little evidence exists on the effect of an energy-unrestricted healthy diet on metabolic syndrome. We evaluated the long-term effect of Mediterranean diets ad libitum on the incidence or reversion of metabolic syndrome.

Methods:

We performed a secondary analysis of the PREDIMED trial — a multicentre, randomized trial done between October 2003 and December 2010 that involved men and women (age 55–80 yr) at high risk for cardiovascular disease. Participants were randomly assigned to 1 of 3 dietary interventions: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with nuts or advice on following a low-fat diet (the control group). The interventions did not include increased physical activity or weight loss as a goal. We analyzed available data from 5801 participants. We determined the effect of diet on incidence and reversion of metabolic syndrome using Cox regression analysis to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results:

Over 4.8 years of follow-up, metabolic syndrome developed in 960 (50.0%) of the 1919 participants who did not have the condition at baseline. The risk of developing metabolic syndrome did not differ between participants assigned to the control diet and those assigned to either of the Mediterranean diets (control v. olive oil HR 1.10, 95% CI 0.94–1.30, p = 0.231; control v. nuts HR 1.08, 95% CI 0.92–1.27, p = 0.3). Reversion occurred in 958 (28.2%) of the 3392 participants who had metabolic syndrome at baseline. Compared with the control group, participants on either Mediterranean diet were more likely to undergo reversion (control v. olive oil HR 1.35, 95% CI 1.15–1.58, p < 0.001; control v. nuts HR 1.28, 95% CI 1.08–1.51, p < 0.001). Participants in the group receiving olive oil supplementation showed significant decreases in both central obesity and high fasting glucose (p = 0.02); participants in the group supplemented with nuts showed a significant decrease in central obesity.

Interpretation:

A Mediterranean diet supplemented with either extra virgin olive oil or nuts is not associated with the onset of metabolic syndrome, but such diets are more likely to cause reversion of the condition. An energy-unrestricted Mediterranean diet may be useful in reducing the risks of central obesity and hyperglycemia in people at high risk of cardiovascular disease. Trial registration: ClinicalTrials.gov, no. ISRCTN35739639.Metabolic syndrome is a cluster of 3 or more related cardiometabolic risk factors: central obesity (determined by waist circumference), hypertension, hypertriglyceridemia, low plasma high-density lipoprotein (HDL) cholesterol levels and hyperglycemia. Having the syndrome increases a person’s risk for type 2 diabetes and cardiovascular disease.^1,2 In addition, the condition is associated with increased morbidity and all-cause mortality.^1,3–5 The worldwide prevalence of metabolic syndrome in adults approaches 25%^6–8 and increases with age,⁷ especially among women,^8,9 making it an important public health issue.Several studies have shown that lifestyle modifications,¹⁰ such as increased physical activity,¹¹ adherence to a healthy diet^12,13 or weight loss,^14–16 are associated with reversion of the metabolic syndrome and its components. However, little information exists as to whether changes in the overall dietary pattern without weight loss might also be effective in preventing and managing the condition.The Mediterranean diet is recognized as one of the healthiest dietary patterns. It has shown benefits in patients with cardiovascular disease^17,18 and in the prevention and treatment of related conditions, such as diabetes,^19–21 hypertension^22,23 and metabolic syndrome.²⁴Several cross-sectional^25–29 and prospective^30–32 epidemiologic studies have suggested an inverse association between adherence to the Mediterranean diet and the prevalence or incidence of metabolic syndrome. Evidence from clinical trials has shown that an energy-restricted Mediterranean diet³³ or adopting a Mediterranean diet after weight loss³⁴ has a beneficial effect on metabolic syndrome. However, these studies did not determine whether the effect could be attributed to the weight loss or to the diets themselves.Seminal data from the PREDIMED (PREvención con DIeta MEDiterránea) study suggested that adherence to a Mediterranean diet supplemented with nuts reversed metabolic syndrome more so than advice to follow a low-fat diet.³⁵ However, the report was based on data from only 1224 participants followed for 1 year. We have analyzed the data from the final PREDIMED cohort after a median follow-up of 4.8 years to determine the long-term effects of a Mediterranean diet on metabolic syndrome.     

Development of guidelines for recently arrived immigrants and refugees to Canada: Delphi consensus on selecting preventable and treatable conditions

Background:

Setting priorities is critical to ensure guidelines are relevant and acceptable to users, and that time, resources and expertise are used cost-effectively in their development. Stakeholder engagement and the use of an explicit procedure for developing recommendations are critical components in this process.

Methods:

We used a modified Delphi consensus process to select 20 high-priority conditions for guideline development. Canadian primary care practitioners who care for immigrants and refugees used criteria that emphasize inequities in health to identify clinical care gaps.

Results:

Nine infectious diseases were selected, as well as four mental health conditions, three maternal and child health issues, caries and periodontal disease, iron-deficiency anemia, diabetes and vision screening.

Interpretation:

Immigrant and refugee medicine covers the full spectrum of primary care, and although infectious disease continues to be an important area of concern, we are now seeing mental health and chronic diseases as key considerations for recently arriving immigrants and refugees.Canada consistently receives more than 239 000 immigrants yearly, up to 35 000 of whom are refugees.¹ Many arrive with similar or better self-reported health than the general Canadian population reports, a phenomenon described as the “healthy immigrant effect.”^2–6 However, subgroups of immigrants, for example refugees, face health disparities and often a greater burden of infectious diseases.^7,8 These health issues sometimes differ from the general population because of differing disease exposures, vulnerabilities, social determinants of health and access to health services before, during and after migration. Cultural and linguistic differences combined with lack of evidence-based guidelines can contribute to poor delivery of services.^9,10Community-based primary health care practitioners see most of the immigrants and refugees who arrive in Canada. This is not only because Canada’s health system centres on primary care practice, but also because people with lower socioeconomic status, language barriers and less familiarity with the system are much less likely to receive specialist care.¹¹Guideline development can be costly in terms of time, resources and expertise.¹² Setting priorities is critical, particularly when dealing with complex situations and limited resources.¹³ There is no standard algorithm on who should and how they should determine top priorities for guidelines, although burden of illness, feasibility and economic considerations are all important.¹⁴ Stakeholder engagement to ensure relevance and acceptability, and the use of an explicit procedure for developing recommendations are critical in guideline development.^15–17 We chose primary care practitioners, particularly those who care for immigrants and refugees, to help the guideline committee select conditions for clinical preventive guidelines for immigrants and refugees with a focus on the first five years of settlement.     

Use of acid-suppressive drugs and risk of pneumonia: a systematic review and meta-analysis

Background

Observational studies and randomized controlled trials have yielded inconsistent findings about the association between the use of acid-suppressive drugs and the risk of pneumonia. We performed a systematic review and meta-analysis to summarize this association.

Methods

We searched three electronic databases (MEDLINE [PubMed], Embase and the Cochrane Library) from inception to Aug. 28, 2009. Two evaluators independently extracted data. Because of heterogeneity, we used random-effects meta-analysis to obtain pooled estimates of effect.

Results

We identified 31 studies: five case–control studies, three cohort studies and 23 randomized controlled trials. A meta-analysis of the eight observational studies showed that the overall risk of pneumonia was higher among people using proton pump inhibitors (adjusted odds ratio [OR] 1.27, 95% confidence interval [CI] 1.11–1.46, I² 90.5%) and histamine₂ receptor antagonists (adjusted OR 1.22, 95% CI 1.09–1.36, I² 0.0%). In the randomized controlled trials, use of histamine₂ receptor antagonists was associated with an elevated risk of hospital-acquired pneumonia (relative risk 1.22, 95% CI 1.01–1.48, I² 30.6%).

Interpretation

Use of a proton pump inhibitor or histamine₂ receptor antagonist may be associated with an increased risk of both community- and hospital-acquired pneumonia. Given these potential adverse effects, clinicians should use caution in prescribing acid-suppressive drugs for patients at risk.Recently, the medical literature has paid considerable attention to unrecognized adverse effects of commonly used medications and their potential public health impact.¹ One group of medications in widespread use is acid-suppressive drugs, which represent the second leading category of medication worldwide, with sales totalling US$26.9 billion in 2005.²Over the past 40 years, the development of potent acid-suppressive drugs, including proton pump inhibitors, has led to considerable improvements in the treatment of acid-related disorders of the upper gastrointestinal tract.³ Experts have generally viewed proton pump inhibitors as safe.⁴ However, potential complications such as gastrointestinal neoplasia, malabsorption of nutrients and increased susceptibility to infection have caused concern.⁵Of special interest is the possibility that acid-suppressive drugs could increase susceptibility to respiratory infections because these drugs increase gastric pH, thus allowing bacterial colonization.^6,7 Several previous studies have shown that treatment with acid-suppressive drugs might be associated with an increased risk of respiratory tract infections⁸ and community-acquired pneumonia in adults^6,7 and children.⁹ However, the association between use of acid-suppressive drugs and risk of pneumonia has been inconsistent.^10–13Given the widespread use of proton pump inhibitors and histamine₂ receptor antagonists, clarifying the potential impact of acid-suppressive therapy on the risk of pneumonia is of great importance to public health.¹⁴ Previous meta-analyses have focused on the role of acid-suppressive drugs in preventing stress ulcer,^11,13,15 but none have examined pneumonia as the primary outcome.The aim of this study was to summarize the association between the use of acid-suppressive drugs and the risk of pneumonia in observational studies and randomized controlled trials.     

Effectiveness of training family physicians to deliver a brief intervention to address excessive substance use among young patients: a cluster randomized controlled trial

Background:

Brief interventions delivered by family physicians to address excessive alcohol use among adult patients are effective. We conducted a study to determine whether such an intervention would be similarly effective in reducing binge drinking and excessive cannabis use among young people.

Methods:

We conducted a cluster randomized controlled trial involving 33 family physicians in Switzerland. Physicians in the intervention group received training in delivering a brief intervention to young people during the consultation in addition to usual care. Physicians in the control group delivered usual care only. Consecutive patients aged 15–24 years were recruited from each practice and, before the consultation, completed a confidential questionnaire about their general health and substance use. Patients were followed up at 3, 6 and 12 months after the consultation. The primary outcome measure was self-reported excessive substance use (≥ 1 episode of binge drinking, or ≥ 1 joint of cannabis per week, or both) in the past 30 days.

Results:

Of the 33 participating physicians, 17 were randomly allocated to the intervention group and 16 to the control group. Of the 594 participating patients, 279 (47.0%) identified themselves as binge drinkers or excessive cannabis users, or both, at baseline. Excessive substance use did not differ significantly between patients whose physicians were in the intervention group and those whose physicians were in the control group at any of the follow-up points (odds ratio [OR] and 95% confidence interval [CI] at 3 months: 0.9 [0.6–1.4]; at 6 mo: 1.0 [0.6–1.6]; and at 12 mo: 1.1 [0.7–1.8]). The differences between groups were also nonsignificant after we re stricted the analysis to patients who reported excessive substance use at baseline (OR 1.6, 95% CI 0.9–2.8, at 3 mo; OR 1.7, 95% CI 0.9–3.2, at 6 mo; and OR 1.9, 95% CI 0.9–4.0, at 12 mo).

Interpretation:

Training family physicians to use a brief intervention to address excessive substance use among young people was not effective in reducing binge drinking and excessive cannabis use in this patient population. Trial registration: Australian New Zealand Clinical Trials Registry, no. ACTRN12608000432314.Most health-compromising behaviours begin in adolescence.¹ Interventions to address these behaviours early are likely to bring long-lasting benefits.² Harmful use of alcohol is a leading factor associated with premature death and disability worldwide, with a disproportionally high impact on young people (aged 10–24 yr).^3,4 Similarly, early cannabis use can have adverse consequences that extend into adulthood.^5–8In adolescence and early adulthood, binge drinking on at least a monthly basis is associated with an increased risk of adverse outcomes later in life.^9–12 Although any cannabis use is potentially harmful, weekly use represents a threshold in adolescence related to an increased risk of cannabis (and tobacco) dependence in adulthood.¹³ Binge drinking affects 30%–50% and excessive cannabis use about 10% of the adolescent and young adult population in Europe and the United States.^10,14,15Reducing substance-related harm involves multisectoral approaches, including promotion of healthy child and adolescent development, regulatory policies and early treatment interventions.¹⁶ Family physicians can add to the public health messages by personalizing their content within brief interventions.^17,18 There is evidence that brief interventions can encourage young people to reduce substance use, yet most studies have been conducted in community settings (mainly educational), emergency services or specialized addiction clinics.^1,16 Studies aimed at adult populations have shown favourable effects of brief alcohol interventions, and to some extent brief cannabis interventions, in primary care.^19–22 These interventions have been recommended for adolescent populations.^4,5,16 Yet young people have different modes of substance use and communication styles that may limit the extent to which evidence from adult studies can apply to them.Recently, a systematic review of brief interventions to reduce alcohol use in adolescents identified only 1 randomized controlled trial in primary care.²³ The tested intervention, not provided by family physicians but involving audio self-assessment, was ineffective in reducing alcohol use in exposed adolescents.²⁴ Sanci and colleagues showed that training family physicians to address health-risk behaviours among adolescents was effective in improving provider performance, but the extent to which this translates into improved outcomes remains unknown.^25,26 Two nonrandomized studies suggested screening for substance use and brief advice by family physicians could favour reduced alcohol and cannabis use among adolescents,^27,28 but evidence from randomized trials is lacking.²⁹We conducted the PRISM-Ado (Primary care Intervention Addressing Substance Misuse in Adolescents) trial, a cluster randomized controlled trial of the effectiveness of training family physicians to deliver a brief intervention to address binge drinking and excessive cannabis use among young people.     

Oral administration of morphine versus ibuprofen to manage postfracture pain in children: a randomized trial

Background:

Recent warnings from Health Canada regarding codeine for children have led to increased use of nonsteroidal anti-inflammatory drugs and morphine for common injuries such as fractures. Our objective was to determine whether morphine administered orally has superior efficacy to ibuprofen in fracture-related pain.

Methods:

We used a parallel group, randomized, blinded superiority design. Children who presented to the emergency department with an uncomplicated extremity fracture were randomly assigned to receive either morphine (0.5 mg/kg orally) or ibuprofen (10 mg/kg) for 24 hours after discharge. Our primary outcome was the change in pain score using the Faces Pain Scale — Revised (FPS-R). Participants were asked to record pain scores immediately before and 30 minutes after receiving each dose.

Results:

We analyzed data from 66 participants in the morphine group and 68 participants in the ibuprofen group. For both morphine and ibuprofen, we found a reduction in pain scores (mean pre–post difference ± standard deviation for dose 1: morphine 1.5 ± 1.2, ibuprofen 1.3 ± 1.0, between-group difference [δ] 0.2 [95% confidence interval (CI) −0.2 to 0.6]; dose 2: morphine 1.3 ± 1.3, ibuprofen 1.3 ± 0.9, δ 0 [95% CI −0.4 to 0.4]; dose 3: morphine 1.3 ± 1.4, ibuprofen 1.4 ± 1.1, δ −0.1 [95% CI −0.7 to 0.4]; and dose 4: morphine 1.5 ± 1.4, ibuprofen 1.1 ± 1.2, δ 0.4 [95% CI −0.2 to 1.1]). We found no significant differences in the change in pain scores between morphine and ibuprofen between groups at any of the 4 time points (p = 0.6). Participants in the morphine group had significantly more adverse effects than those in the ibuprofen group (56.1% v. 30.9%, p < 0.01).

Interpretation:

We found no significant difference in analgesic efficacy between orally administered morphine and ibuprofen. However, morphine was associated with a significantly greater number of adverse effects. Our results suggest that ibuprofen remains safe and effective for outpatient pain management in children with uncomplicated fractures. Trial registration: ClinicalTrials.gov, no. {"type":"clinical-trial","attrs":{"text":"NCT01690780","term_id":"NCT01690780"}}NCT01690780.There is ample evidence that analgesia is underused,¹ underprescribed,² delayed in its administration² and suboptimally dosed ³ in clinical settings. Children are particularly susceptible to suboptimal pain management⁴ and are less likely to receive opioid analgesia.⁵ Untreated pain in childhood has been reported to lead to short-term problems such as slower healing⁶ and to long-term issues such as anxiety, needle phobia,⁷ hyperesthesia⁸ and fear of medical care.⁹ The American Academy of Pediatrics has reaffirmed its advocacy for the appropriate use of analgesia for children with acute pain.¹⁰Fractures constitute between 10% and 25% of all injuries.¹¹ The most severe pain after an injury occurs within the first 48 hours, with more than 80% of children showing compromise in at least 1 functional area.¹² Low rates of analgesia have been reported after discharge from hospital.¹³ A recently improved understanding of the pharmacogenomics of codeine has raised significant concerns about its safety,^14,15 and has led to a Food and Drug Administration boxed warning¹⁶ and a Health Canada advisory¹⁷ against its use. Although ibuprofen has been cited as the most common agent used by caregivers to treat musculoskeletal pain,^12,13 there are concerns that its use as monotherapy may lead to inadequate pain management.^6,18 Evidence suggests that orally administered morphine¹³ and other opioids are increasingly being prescribed.¹⁹ However, evidence for the oral administration of morphine in acute pain management is limited.^20,21 Thus, additional studies are needed to address this gap in knowledge and provide a scientific basis for outpatient analgesic choices in children. Our objective was to assess if orally administered morphine is superior to ibuprofen in relieving pain in children with nonoperative fractures.     

Secular trends in acute dialysis after elective major surgery �� 1995 to 2009

Background:

Acute kidney injury is a serious complication of elective major surgery. Acute dialysis is used to support life in the most severe cases. We examined whether rates and outcomes of acute dialysis after elective major surgery have changed over time.

Methods:

We used data from Ontario’s universal health care databases to study all consecutive patients who had elective major surgery at 118 hospitals between 1995 and 2009. Our primary outcomes were acute dialysis within 14 days of surgery, death within 90 days of surgery and chronic dialysis for patients who did not recover kidney function.

Results:

A total of 552 672 patients underwent elective major surgery during the study period, 2231 of whom received acute dialysis. The incidence of acute dialysis increased steadily from 0.2% in 1995 (95% confidence interval [CI] 0.15–0.2) to 0.6% in 2009 (95% CI 0.6–0.7). This increase was primarily in cardiac and vascular surgeries. Among patients who received acute dialysis, 937 died within 90 days of surgery (42.0%, 95% CI 40.0–44.1), with no change in 90-day survival over time. Among the 1294 patients who received acute dialysis and survived beyond 90 days, 352 required chronic dialysis (27.2%, 95% CI 24.8–29.7), with no change over time.

Interpretation:

The use of acute dialysis after cardiac and vascular surgery has increased substantially since 1995. Studies focusing on interventions to better prevent and treat perioperative acute kidney injury are needed.More than 230 million elective major surgeries are done annually worldwide.¹ Acute kidney injury is a serious complication of major surgery. It represents a sudden loss of kidney function that affects morbidity, mortality and health care costs.² Dialysis is used for the most severe forms of acute kidney injury. In the nonsurgical setting, the incidence of acute dialysis has steadily increased over the last 15 years, and patients are now more likely to survive to discharge from hospital.^3–5 Similarly, in the surgical setting, the incidence of acute dialysis appears to be increasing over time,^6–10 with declining inhospital mortality.^8,10,11Although previous studies have improved our understanding of the epidemiology of acute dialysis in the surgical setting, several questions remain. Many previous studies were conducted at a single centre, thereby limiting their generalizability.^6,12–14 Most multicentre studies were conducted in the nonsurgical setting and used diagnostic codes for acute kidney injury not requiring dialysis; however, these codes can be inaccurate.^15,16 In contrast, a procedure such as dialysis is easily determined. The incidence of acute dialysis after elective surgery is of particular interest given the need for surgical consent, the severe nature of the event and the potential for mitigation. The need for chronic dialysis among patients who do not recover renal function after surgery has been poorly studied, yet this condition has a major affect on patient survival and quality of life.¹⁷ For these reasons, we studied secular trends in acute dialysis after elective major surgery, focusing on incidence, 90-day mortality and need for chronic dialysis.     

Effectiveness of interventions to reduce aggression and injuries among ice hockey players: a systematic review

Background:

The increasing incidence of injuries related to playing ice hockey is an important public health issue. We conducted a systematic review to evaluate the effectiveness of interventions designed to reduce injuries related to aggressive acts in ice hockey.

Methods:

We identified relevant articles by searching electronic databases from their inception through July 2012, by using Internet search engines, and by manually searching sports medicine journals, the book series Safety in Ice Hockey and reference lists of included articles. We included studies that evaluated interventions to reduce aggression-related injuries and reported ratings of aggressive behaviour or rates of penalties or injuries.

Results:

We identified 18 eligible studies. Most involved players in minor hockey leagues. Of 13 studies that evaluated changes in mandatory rules intended to lessen aggression (most commonly the restriction of body-checking), 11 observed a reduction in penalty or injury rates associated with rule changes, and 9 of these showed a statistically significant decrease. The mean number of penalties decreased by 1.2–5.9 per game, and injury rates decreased 3- to 12-fold. All 3 studies of educational interventions showed a reduction in penalty rates, but they were not powered or designed to show a change in injury rates. In 2 studies of cognitive behavioural interventions, reductions in aggressive behaviours were observed.

Interpretation:

Changes to mandatory rules were associated with reductions in penalties for aggressive acts and in injuries related to aggression among ice hockey players. Effects of educational and cognitive behavioural interventions on injury rates are less clear. Well-designed studies of multifaceted strategies that combine such approaches are required.Over the last 15 years, the incidence of brain and spinal cord injuries among ice hockey players has increased.¹ A recent study involving players in junior leagues found that, in the 2009/10 hockey season, the incidence of game-related concussions was 7 times higher than the highest rate previously reported in 1998/99.² Brain injuries frequently result from aggressive bodychecking³ and account for 15% of injuries among players 9–16 years of age.^4,5 In a study of a community-based hockey program involving boys aged 9–15 years, hostile aggressive acts, which have an intention to do harm,⁶ were the primary cause of injury in one-third of games in which an injury resulted.⁷ Among high school students in Minnesota who played varsity ice hockey, those who played to relieve aggression were 4 times more likely than other players to experience a concussion.⁸ These findings highlight the association between aggressive behaviour and injury in ice hockey. However, little is known about what can be done to reduce this behaviour to create a safer environment for the sport.Existing reviews about reducing injury in sport have primarily assessed equipment or risk factors associated with injury.^9–11 Recent systematic reviews highlighted the risks of bodychecking and renewed calls for policies to disallow bodychecking among youth playing ice hockey.^3,12 We conducted a systematic review to assess the effectiveness of interventions designed to reduce aggressive acts and related injuries among ice hockey players. We were particularly interested in evaluating the effectiveness of rule changes, educational interventions and behavioural modification in reducing aggressive acts and related injuries.     

Trends in suicidal behaviour and use of mental health services in Canadian military and civilian populations

Background:In the context of the Canadian mission in Afghanistan, substantial media attention has been placed on mental health and lack of access to treatment among Canadian Forces personnel. We compared trends in the prevalence of suicidal behaviour and the use of mental health services between Canadian military personnel and the general population from 2002 to 2012/13.Methods:We obtained data for respondents aged 18–60 years who participated in 4 nationally representative surveys by Statistics Canada designed to permit comparisons between populations and trends over time. Surveys of the general population were conducted in 2002 (n = 25 643) and 2012 (n = 15 981); those of military personnel were conducted in 2002 (n = 5153) and 2013 (n = 6700). We assessed the lifetime and past-year prevalence of suicidal ideation, plans and attempts, as well as use of mental health services.Results:In 2012/13, but not in 2002, military personnel had significantly higher odds of both lifetime and past-year suicidal ideation than the civilian population (lifetime: adjusted odds ratio [OR] 1.32, 95% confidence interval [CI] 1.17–1.50; past year: adjusted OR 1.34, 95% CI 1.09–1.66). The same was true for suicidal plans (lifetime: adjusted OR 1.64, 95% CI 1.35–1.99; past year: adjusted OR 1.66, 95% CI 1.18–2.33). Among respondents who reported past-year suicidal ideation, those in the military had a significantly higher past-year utilization rate of mental health services than those in the civilian population in both 2002 (adjusted OR 2.02, 95% CI 1.31–3.13) and 2012/13 (adjusted OR 3.14, 95% CI 1.86–5.28).Interpretation:Canadian Forces personnel had a higher prevalence of suicidal ideation and plans in 2012/13 and a higher use of mental health services in 2002 and 2012/13 than the civilian population.Suicide is a leading cause of death around the world in military and civilian populations. ^1–3 There has been increased attention paid to suicidal behaviour in Canada, and a number of initiatives are being put in place to prevent suicide through better recognition and treatment of mental disorders.⁴ Examples of major Canadian initiatives include creation of a national Mental Health Commission of Canada,⁵ development of a federal framework for suicide prevention,⁶ large investments in military and veteran mental health services, and targeted efforts to formulate comprehensive suicide prevention strategies among military and veteran populations.^4,7 Despite these initiatives, the prevalence of suicide in Canada has not changed appreciably in recent years.^8,9A recent report on suicides in the Canadian Forces did not find an overall increase in the prevalence of suicide between 1995 and 2014.¹⁰ However, the prevalence increased substantially over that time in the subgroup of male army personnel in the Regular Force.¹⁰ In the United States, the army has observed steady increases in the prevalence of suicide attempts and completed suicide by soldiers since 2004, whereas the prevalence of suicide has remained unchanged in the general population.^3,11,12 Findings from the US are not generalizable to the Canadian military because of differences in recruitment, deployment policies and health care systems.¹³Suicidal ideation, plans and attempts are strong risk factors for death by suicide.¹⁴ A history of suicide attempt is the strongest predictor of future attempts.¹⁵ Suicidal ideation is also an important target for intervention because previous work has shown a rapid transition from first-onset suicidal ideation to plans and attempts within the same year.¹⁶ It remains unknown whether nonfatal suicidal behaviour in military and civilian populations in Canada has changed over time.Another area of major public health concern is that most people with suicidal behaviour do not receive mental health services. In nationally representative civilian samples in Canada and 21 other countries, most respondents with suicidal behaviours (60%) did not receive mental health services. ^17,18 The use of such services among Canadian military personnel with suicidal behaviours remains unknown. The media has recently been critical of the Canadian Armed Forces and Veterans Affairs Canada about insufficient services available to military personnel and veterans.¹⁹We compared trends in the prevalence of suicidal behaviours and help-seeking between Canadian civilian and military populations over a 10-year period from 2002 to 2012/13 using data from 4 nationally representative surveys.     

Diagnosed hypertension in Canada: incidence, prevalence and associated mortality

Background:

Hypertension is a leading risk factor for cardiovascular diseases. Our objectives were to examine the prevalence and incidence of diagnosed hypertension in Canada and compare mortality among people with and without diagnosed hypertension.

Methods:

We obtained data from linked health administrative databases from each province and territory for adults aged 20 years and older. We used a validated case definition to identify people with hypertension diagnosed between 1998/99 and 2007/08. We excluded pregnant women from the analysis.

Results:

This retrospective population-based study included more than 26 million people. In 2007/08, about 6 million adults (23.0%) were living with diagnosed hypertension and about 418 000 had a new diagnosis. The age-standardized prevalence increased significantly from 12.5% in 1998/99 to 19.6% in 2007/08, and the incidence decreased from 2.7 to 2.4 per 100. Among people aged 60 years and older, the prevalence was higher among women than among men, as was the incidence among people aged 75 years and older. The prevalence and incidence were highest in the Atlantic region. For all age groups, all-cause mortality was higher among adults with diagnosed hypertension than among those without diagnosed hypertension.

Interpretation:

The overall prevalence of diagnosed hypertension in Canada from 1998 to 2008 was high and increasing, whereas the incidence declined during the same period. These findings highlight the need to continue monitoring the effectiveness of efforts for managing hypertension and to enhance public health programs aimed at preventing hypertension.Globally, raised blood pressure is the leading risk factor for death, accounting for about 13% of all deaths,^1,2 and it is the strongest risk factor for lost years of healthy life.¹ Left untreated, hypertension can increase the risk of stroke, coronary artery disease, dementia, heart and kidney failure, and other chronic diseases.^3–6 Managing hypertension through lifestyle modification or the use of antihypertensive medications, or both, can help mitigate these outcomes.⁷ Over the past decades in Canada, mortality associated with cardiovascular diseases has decreased,⁸ partly because of increased awareness and diagnosis of hypertension and better control of blood pressure.^9,10 However, the prevalence of hypertension remains high, and currently there are no mechanisms to track new cases at the national level.To date, information about hypertension in Canada has been mainly obtained by health surveys conducted at the provincial or national levels. Such surveys typically provide prevalence (not incidence) data and include limited data about trends over time.^11–15 National health surveys in Canada are resource intensive, do not include information about people who live in remote areas or institutions, and may underestimate hypertension prevalence because of recall bias and non-response.¹⁶ The use of administrative data that is population-based and routinely collected, such as physician claims and hospital discharge data, allows for a more comprehensive picture of this condition. Other important advantages of using administrative data include the readiness of the data to be analyzed, cost-efficiency, wide geographic coverage and the relatively complete capture of patient contact with the health care system (i.e., less prone to selection bias).Several recent studies in Canada and the United States have established valid methods for using administrative data to identify cases of hypertension.^16–23 In a study conducted in Ontario involving women and men aged 20 years and older, Tu and colleagues found that the prevalence and incidence of diagnosed hypertension were 24.5% in 2005 and 3.2% in 2004, respectively.²⁴ We used the same validated case definition to examine the prevalence and incidence of diagnosed hypertension in Canada from 1998/99 to 2007/08 by age and by province and territory. We also compared all-cause mortality by age and sex among those with and without diagnosed hypertension.