HBV转基因小鼠--乙型肝炎研究的重要工具

HBV感染具有严格的种属特异性和组织亲嗜性,所以可用于研究的动物模型很少。随着转基因技术的出现和发展,人们通过研制转基因动物模型来研究病毒致病机理。把HBV的DNA或其片段转入小鼠受精卵建立起来的HBV转基因小鼠,已被广泛地应用于乙型肝炎的研究中,主要体现在以下3个方面：研究HBV的致病机制、与肝细胞癌的关系及寻找、评价治疗乙肝的方法。     

Risk of stillbirth in the relation to water disinfection by-products: a population-based case-control study in Taiwan

Background

Few epidemiological studies that have assessed the relation between water disinfection by-products (DBPs) and the risk of stillbirth provide inconsistent results. The objective was to assess the relation between exposure to water disinfection by-products and the risk of stillbirth.

Methods

We conducted a population-based case-control study of 3,289 cases of stillbirth and a random sample of 32,890 control subjects from 396,049 Taiwanese newborns in 2001–2003 using information from the Birth Registry and Waterworks Registry in Taiwan. We compared the risk of stillbirth in four disinfection by-product exposure categories based on the levels of total trihalomethanes (TTHMs) representing high (TTHMs 20+ µg/L), medium (TTHMs 10–19 µg/L), low exposure (TTHMs 5–9 µg/L), and 0–4 µg/L as the reference category. In addition, we conducted a meta-analysis of the results from the present and 5 previous studies focusing on stillbirth.

Findings

In logistic regression analysis adjusting for gender, maternal age, plurality, conception of season and population density of the municipality where the mother lived during pregnancy, the odds ratio (OR) for stillbirth was 1.10 (95% CI 1.00–1.21) for medium exposure and 1.06 (95% 0.96–1.17) for high exposure compared to reference category. In the meta-analysis, the summary odds ratio for stillbirth (1.11, 95% CI: 1.03, 1.19) was consistently elevated.

Conclusions

The present study is consistent with the hypothesis that the risk of stillbirth is related to prenatal exposure to disinfection by-products. This finding on stillbirth is consistent with previous epidemiologic studies, which strengthens the weight of evidence.     

Interpretations of condom use and nonuse among young Norwegian gay men: a qualitative study

Among the strategies adopted by gay men and the gay community for HIV prevention, the promotion of condom use has been pivotal. This article discusses young gay Norwegian men's interpretations of condom use and nonuse. Meanings mediated by (non)use of condoms are meanings in the making rather than antecedently and inalterably fixed. How young gay men interpret (non)use of condoms varies with and depends upon context or relationship. In this article, young men's readings of (non)use of condoms are discussed in the contexts of (anal) sex; surrender to pleasure; semen and intimacy; and respect, disrespect, and humiliation. How condom use functions as a sign for both trust and mistrust also is discussed.     

Risk of cancer among patients with herpes zoster infection: a population-based study

Background:

Whether the risk of cancer is increased among patients with herpes zoster is unclear. We investigated the risk of cancer among patients with herpes zoster using a nationwide health registry in Taiwan.

Methods:

We identified 35 871 patients with newly diagnosed herpes zoster during 2000–2008 from the National Health Insurance Research Database in Taiwan. We analyzed the standardized incidence ratios for various types of cancer.

Results:

Among patients with herpes zoster, 895 cases of cancer were reported. Patients with herpes zoster were not at increased risk of cancer (standardized incidence ratio 0.99, 95% confidence interval 0.93–1.06). Among the subgroups stratified by sex, age and years of follow-up, there was also no increased risk of overall cancer.

Interpretation:

Herpes zoster is not associated with increased risk of cancer in the general population. These findings do not support extensive investigations for occult cancer or enhanced surveillance for cancer in patients with herpes zoster.Herpes zoster, or shingles, is caused by reactivation of the varicella–zoster virus, a member of the Herpesviridae family. Established risk factors for herpes zoster include older age, chronic kidney disease, malignant disease and immunocompromised conditions (e.g., those experienced by patients with AIDS, transplant recipients, and those taking immunosuppressive medication because of autoimmune diseases).^1–5 Herpes zoster occurs more frequently among patients with cancer than among those without cancer;^6,7 however the relation between herpes zoster and risk of subsequent cancer is not well established.In 1955, Wyburn-Mason and colleagues reported several cases of skin cancer that arose from the healed lesions of herpes zoster.⁸ In 1972, a retrospective cohort study and a case series reported a higher prevalence of herpes zoster among patients with cancer, especially hematological cancer;^6,7 however, they did not investigate whether herpes zoster was a risk factor for cancer. In 1982, Ragozzino and colleagues found no increased incidence of cancer (including hematologic malignancy) among patients with herpes zoster.⁹ There have been reports of significantly increased risk of some subtypes of cancer among patients aged more than 65 years with herpes zoster¹⁰ and among those admitted to hospital because of herpes zoster.¹¹ Although these studies have suggested an association between herpes zoster and subsequent cancer, their results might not be generalizable because of differences in the severity of herpes zoster in the enrolled patients.Whether the risk of cancer is increased after herpes zoster remains controversial. The published studies^8–11 were nearly all conducted in western countries, and data focusing on Asian populations are lacking.¹² The results from western countries may not be directly generalizable to other ethnic groups because of differences in cancer types and profiles. Recently, a study reported that herpes zoster ophthalmicus may be a marker of increased risk of cancer in the following year.¹³ In the present study, we investigated the incidence rate ratio of cancer, including specific types of cancer, after diagnosis of herpes zoster.     

Research ethics training in Peru: a case study

With the rapidly increasing number of health care professionals seeking international research experience, comes an urgent need for enhanced capacity of host country institutional review boards (IRB) to review research proposals and ensure research activities are both ethical and relevant to the host country customs and needs. A successful combination of distance learning, interactive courses and expert course instructors has been applied in Peru since 2004 through collaborations between the U.S. Naval Medical Research Center Detachment, the University of Washington and the Department of Clinical Bioethics of the National Institutes of Health to provide training in ethical conduct of research to IRB members and researchers from Peru and other Latin American countries. All training activities were conducted under the auspices of the Peruvian National Institute of Health (INS), Ministry of Health. To date, 927 people from 12 different Latin American countries have participated in several of these training activities. In this article we describe our training model.     

Photoperiodism: the consistent use of CONSTANS

Photoperiodic induction of flowering in the long-day plant Arabidopsis is mediated by the circadian regulated CONSTANS gene. New evidence suggests that CONSTANS-like genes have a similar role in short-day induction of flowering of rice and Pharbitis.     

Rates of health services use among residents of retirement homes in Ontario: a population-based cohort study

Background:Because there are no standardized reporting systems specific to residents of retirement homes in North America, little is known about the health of this distinct population of older adults. We evaluated rates of health services use by residents of retirement homes relative to those of residents of long-term care homes and other populations of older adults.Methods:We conducted a retrospective cohort study using population health administrative data from 2018 on adults 65 years or older in Ontario. We matched the postal codes of individuals to those of licensed retirement homes to identify residents of retirement homes. Outcomes included rates of hospital-based care and physician visits.Results:We identified 54 733 residents of 757 retirement homes (mean age 86.7 years, 69.0% female) and 2 354 385 residents of other settings. Compared to residents of long-term care homes, residents of retirement homes had significantly higher rates per 1000 person months of emergency department visits (10.62 v. 4.48, adjusted relative rate [RR] 2.61, 95% confidence interval [CI] 2.55 to 2.67), hospital admissions (5.42 v. 2.08, adjusted RR 2.77, 95% CI 2.71 to 2.82), alternate level of care (ALC) days (6.01 v. 2.96, adjusted RR 1.51, 95% CI 1.48 to 1.54), and specialist physician visits (6.27 v. 3.21, adjusted RR 1.64, 95% CI 1.61 to 1.68), but a significantly lower rate of primary care visits (16.71 v. 108.47, adjusted RR 0.13, 95% CI 0.13 to 0.14).Interpretation:Residents of retirement homes are a distinct population with higher rates of hospital-based care. Our findings can help to inform policy debates about the need for more coordinated primary and supportive health care in privately operated congregate care homes.

In the continuum of care services and settings for older adults lies home care at one end and long-term care at the other.¹ Home care services may include, but are not limited to, nursing care, personal care, homemaking services, and physiotherapy and occupational therapy for older adults who live independently in their community. Home care services are publicly funded under the Ontario Health Insurance Plan (OHIP).^2,3 Long-term care homes provide access to 24-hour nursing and personal care and operate at full capacity in Ontario, with waiting lists of 6 months or longer before an older adult in the community could receive an offer for a bed.^2,4 Retirement homes are thought to fit between home care and long-term care in this continuum.¹Retirement homes are referred to as assisted-living facilities in other North American jurisdictions, and they are private, congregate living environments that deliver supportive care to adults who are 65 years of age and older.^3,5,6 These homes are often marketed to provide a lifestyle and community, and they provide a range of assisted-living care services (e.g., meals, nursing services, etc.).^5,7 Retirement homes predominately operate on a private, for-profit business model, and the room, board and services are purchased by residents.^3,5 In Ontario, retirement homes are regulated through an independent, not-for-profit regulator (i.e., Retirement Homes Regulatory Authority [RHRA]).⁵ There are more than 700 licensed retirement homes in Ontario with over 70 000 available beds occupied by over 55 000 residents, which is comparable to the number of available beds in the long-term care sector.^3,5,6,8 Retirement homes are legislated differently from long-term care homes and primarily cater to adults who do not require 24-hour nursing care.^1,5,9 Unlike long-term care homes, no standardized reporting system is available to identify and describe residents of retirement homes.¹⁰ These residents are conceptualized as having fewer needs for care because they reside in a congregate care home to support independent living; however, this has been difficult to verify given there are no population-level data.A body of literature from the United States has described residents of assisted-living facilities and the sector,^11–17 but Canadian literature is comparatively nascent. Canadian studies have investigated transitions to a long-term care home, risk of hospital admission among those who live with dementia, and life events and health conditions associated with the transition to a congregate care setting.^7,9,18–20 At present, a Canadian population-level cohort of residents of retirement homes that describes the individual-level characteristics and use of health services of the older adults who reside in these homes appears to be lacking. Therefore, it is difficult to position this sector in the gradient of services and housing options for older adults in Canada.We created a population-level cohort of residents in retirement homes and sought to evaluate their rates of health services utilization relative to residents of long-term care homes and other populations of older adults (i.e., home care recipients and community-dwelling older adults) in Ontario.     

Determinants of condom use among youth in Madagascar

The objective of this study was to identify the key determinants of condom use with regular and casual partners among youth in Madagascar.Data stem from a reproductive health survey conducted in October-December 2000 among a representative sample of 2440 youth aged 15-24 living in Toamasina province. Following theoretical models of behaviour change, logistic regression was used to assess the effect of AIDS awareness,personal risk perception, condom access, perceived condom effectiveness,self-efficacy and social support on condom use. Among sexually experienced youth, only about four in ten males and two in ten females have ever used condoms. Fewer than 15% of youth used a condom in last intercourse with their regular partner. Whether youth will try condoms appears to depend largely on the perceived effectiveness of condoms for family planning, access to a nearby condom source, parental support for condom use, and patterns of risky sexual behaviour. Young males' likelihood of using a condom with a regular partner increases significantly if they perceive condoms to be effective for family planning (OR=11.4; p=0.019). For females, it increases with level of self-efficacy (OR=2 1; p=0.042) and having discussed HIV prevention with someone in the last year (OR=2.8; p=0.022). Among males,condom use with casual partners is significantly higher among those who perceive themselves to be at high risk of sexually transmitted infections(OR=2.3; p=0.014), who believe condoms are effective for family planning(OR=2.8; p=0.048), who have good access to condoms (OR=2.9; p=0.002)and who perceive their parents support condom use (OR=1-7; p=0.048). In conclusion, very few youth in Toamasina are using condoms, highlighting the need to continue and expand adolescent reproductive health interventions. In this low HIV prevalence setting, it is important for these programmes to emphasize that condoms are effective for both pregnancy prevention and STI/HIV prevention.     

Helicobacter pylori infection and gastroesophageal reflux in a population-based study (The HUNT Study)

BACKGROUND AND AIM: It has been suggested that Helicobacter pylori infection may prevent gastroesophageal reflux, possibly through gastric atrophy. Since, however, previous results are contradictory and no population-based studies are available, the relationship between H. pylori and reflux remains uncertain. The aim of this study was to investigate this relationship in a population-based, nested, case-control study. METHODS: From a cohort of 65,363 individuals, representing 71.2% of the adult population in the Norwegian county of Nord-Trondelag, we randomly selected 472 persons with recurrent reflux symptoms (cases) and 472 without such symptoms (controls). Occurrence of H. pylori and its virulence factor cagA was determined serologically, using an immunoblot assay. Gastric atrophy was assessed through serum levels of pepsinogen I. Odds ratios (OR) with 95% confidence intervals (CI), adjusted for potential confounding factors, represented relative risks. RESULTS: H. pylori infection was not associated with a decreased risk of reflux symptoms (OR 1.1, 95% CI 0.8-1.6), irrespective of positive cagA status (OR 1.1, 95% CI 0.8-1.5). Gastric atrophy reduced the risk of reflux symptoms (OR 0.2, 95% CI 0.0-0.6). Infection with H. pylori entailed a ninefold increase in the risk of gastric atrophy compared to non-infection (OR 8.9, 95% CI 2.0-39.9). CONCLUSIONS: H. pylori infection, irrespective of cagA status, did not affect the occurrence of reflux symptoms in this population-based setting. Infected individuals are at increased risk of gastric atrophy, which in turn reduces reflux symptoms, but due to the low frequency of gastric atrophy among infected individuals overall, there was no association with reflux symptoms on a population level.     

From awareness to adoption: the effect of AIDS education and condom social marketing on condom use in Tanzania (1993-1996)

This paper uses retrospective event-history data covering a four-year period to examine the timing of exposure to HIV/AIDS education and social marketing condom promotion campaigns, relative to the timing of changes in sexual risk behaviour in Tanzania. Analysis of the event-history data shows that the process of exposure to AIDS education messages and exposure to brand advertising for Salama brand condoms was very different. While exposure to AIDS education was early and gradual, exposure to Salama brand condoms started later, but was much more rapid. After one year of advertising, over half of the target population had been reached by the Salama advertising campaign, mostly through newspapers, radio and television. During the study period, condom use increased from 15% at the beginning of 1993 to 42% at the end of 1996. Increases in condom use were driven both by men who became sexually active, and by men who were not yet protected, or not fully protected. The results further show that it is uncommon for men who adopted condom use to return to more risky behaviour, which suggests that behaviour change in the study population is permanent.     

Early medication use in new-onset rheumatoid arthritis may delay joint replacement: results of a large population-based study

IntroductionUse of disease-modifying anti-rheumatic drugs (DMARDs) in rheumatoid arthritis (RA) may prevent joint damage and potentially reduce joint replacement surgeries. We assessed the association between RA drug use and joint replacement in Quebec, Canada.MethodsA cohort of new-onset RA patients was identified from Quebec’s physician billing and hospitalization databases from 2002–2011. The outcome was defined using procedure codes submitted by orthopedic surgeons. Medication use was obtained from pharmacy databases. We used alternative Cox regression models with time-dependent variables measuring the cumulative effects of past use during different time windows (one model focussing on the first year after cohort entry) for methotrexate (MTX), and other DMARDs. Models were adjusted for baseline sociodemographics, co-morbidity and prior health service use, time-dependent cumulative use of other drugs (anti-tumor necrosis factor [anti-TNF] agents, other biologics, cyclooxygenase-2 inhibitors [COXIBs], nonselective nonsteroidal antiinflammatory drugs [NSAIDs], and systemic steroids), and markers of disease severity.ResultsDuring follow-up, 608 joint replacements occurred among 11,333 patients (median follow-up: 4.6 years). The best-fitting model relied on the cumulative early use (within the first year after cohort entry) of MTX and of other DMARDs, with an interaction between MTX and other DMARDs. In this model, greater exposure within the first year, to either MTX (adjusted hazard ratio, HR = 0.95 per 1 month, 95 % confidence interval, 95 % CI 0.93-0.97) or other DMARDs (HR = 0.97, 95 % CI 0.95-0.99) was associated with longer time to joint replacement.ConclusionsOur results suggest that longer exposure to either methotrexate (MTX) or other DMARDs within the first year after RA diagnosis is associated with longer time to joint replacement surgery.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0713-3) contains supplementary material, which is available to authorized users.     

Mortality among patients with frequent emergency department use for alcohol-related reasons in Ontario: a population-based cohort study

BACKGROUND:Little is known about the risk of death among people who visit emergency departments frequently for alcohol-related reasons, including whether mortality risk increases with increasing frequency of visits. Our primary objective was to describe the sociodemographic and clinical characteristics of this high-risk population and examine their 1-year overall mortality, premature mortality and cause of death as a function of emergency department visit frequency in Ontario, Canada.METHODS:We conducted a population-based retrospective cohort study using linked health administrative data (Jan. 1, 2010, to Dec. 31, 2016) in Ontario for people aged 16–105 years who made at least 2 emergency department visits for mental or behavioural disorders due to alcohol within 1 year. We subdivided the cohort based on visit frequency (2, 3 or 4, or ≥ 5). The primary outcome was 1-year mortality, adjusted for age, sex, income, rural residence and presence of comorbidities. We examined premature mortality using years of potential life lost (YPLL).RESULTS:Of the 25 813 people included in the cohort, 17 020 (65.9%) had 2 emergency department visits within 1 year, 5704 (22.1%) had 3 or 4 visits, and 3089 (12.0%) had 5 or more visits. Males, people aged 45–64 years, and those living in urban centres and lower-income neighbourhoods were more likely to have 3 or 4 visits, or 5 or more visits. The all-cause 1-year mortality rate was 5.4% overall, ranging from 4.7% among patients with 2 visits to 8.8% among those with 5 or more visits. Death due to external causes (e.g., suicide, accidents) was most common. The adjusted mortality rate was 38% higher for patients with 5 or more visits than for those with 2 visits (adjusted hazard ratio 1.38, 95% confidence interval 1.19–1.59). Among 25 298 people aged 16–74 years, this represented 30 607 YPLL.INTERPRETATION:We observed a high mortality rate among relatively young, mostly urban, lower-income people with frequent emergency department visits for alcohol-related reasons. These visits are opportunities for intervention in a high-risk population to reduce a substantial mortality burden.

Alcohol is a leading driver of morbidity and mortality worldwide.¹ An estimated 3 million deaths in 2016 — 5% of all global deaths — were attributable to alcohol consumption.² The 2016 Global Burden of Disease Study showed that alcohol was the single greatest risk factor for ill health worldwide among people aged 15–49 years.³ In Canada, hospital admissions for alcohol-attributable conditions out-number those for myocardial infarction.⁴ Alcohol-related harms cost Canadians about $14.6 billion annually, with $3.3 billion in health care costs.⁵In addition to the societal impact of mental and behavioural disorders due to alcohol (henceforth referred to as alcohol-related) — mainly acute intoxication and withdrawal — these disorders are common reasons for emergency department visits.^6,7 Data from the United States and Canada, furthermore, suggest that alcohol-related emergency department visits have increased in recent years.^8,9 For example, a study in Ontario showed that, between 2003 and 2016, the age-standardized rates of alcohol-attributable emergency department visits increased by 86.5% in women and 53.2% in men.⁸ People who visit emergency departments frequently for alcohol-related reasons have high levels of comorbidity and social disadvantage,^10,11 and represent a readily identifiable patient population for whom interventions to address unmet social and health care needs could be developed.^12–14 A systematic review suggested that screening and brief intervention for alcohol-related problems in the emergency department is a promising approach for reducing problematic alcohol consumption.¹³Despite this, little is known about the risk of death, a key outcome for health system performance, among people who use emergency departments frequently for alcohol-related reasons, including whether mortality risk increases with increasing frequency of visits. To address this gap, our primary objective was to describe the sociodemographic and clinical characteristics of this high-risk population and examine their 1-year overall mortality, premature mortality and cause of death as a function of emergency department visit frequency in Ontario, the most populous Canadian province.¹⁵     

Pain following stroke: a population-based follow-up study

Background and Purpose

Chronic pain is increasingly recognized as a consequence of stroke. This study aimed to describe the prevalence and pain types of new onset chronic pain (“novel pain”) in patients with stroke compared with a randomly selected reference group from the general population and to identify factors associated with pain development in stroke patients.

Methods

In a population-based follow-up design, development of chronic pain after stroke was assessed by a questionnaire sent to consecutive stroke patients, registered in a Danish national stroke database, two years after their stroke. A randomly selected sex- and age-matched reference group from the same catchment area received a similar questionnaire about development of new types of chronic pain in the same time period. A total of 608 stroke patients and 519 reference subjects were included in the study.

Results

Development of novel pain was reported by 39.0% of stroke patients and 28.9% of reference subjects (OR 1.57, CI 1.21-2.04), and was associated with low age and depression in a multivariate model. Daily intake of pain medication for novel pain was reported by 15.3% and 9.4% of the stroke and reference population, respectively. Novel headache, shoulder pain, pain from increased muscle stiffness, and other types of novel pain were more common in stroke patients, whereas joint pain was equally common in the two groups.

Conclusions

Development of chronic pain is more common in stroke patients compared with sex- and age-matched reference subjects. Evaluation of post-stroke pain should be part of stroke follow-up.     

Oncogenic human papillomavirus genital infection in southern Iranian women: population-based study versus clinic-based data

ABSTRACT: BACKGROUND: Epidemiological studies on genital human papilloma viruses infection (HPVs) in general population are crucial for the implementation of health policy guidelines for developing the strategies to prevent the primary and secondary cervical cancer. In different parts of Iran, there is a lack of population-based studies to determine the prevalence of HPV in the general population. The aim of this population-based study is to compare the prevalence rate of genital HPV infection among reproductive women with our previous clinic-based data, which showed a prevalence rate of 5% in women in southern Iran. RESULTS: Using general primers for all genotypes of HPV, of 799 randomly selected women, five (0.63%, 95% CI 0.23-1.55%) tested positive for HPV DNA. Overall, seven different HPV genotypes were detected: six types (16, 18, 31, 33, 51 and 56) were carcinogenic, or "high risk genotypes" and one genotype (HPV-66) was "probably carcinogenic." CONCLUSIONS: In a population-based study, the prevalence of HPV infection among southern Iranian women was lower than that observed worldwide. However, our gynaecological clinic-based study on the prevalence of HPV infection showed results comparable with other studies in the Middle East and Persian Gulf countries. Since gynaecological clinic-based data may generally overestimate HPV prevalence, estimates of prevalence according to clinic-based data should be adjusted downward by the population-based survey estimates.     

Metabolic syndrome in relation to Barrett⿿s esophagus and esophageal adenocarcinoma: Results from a large population-based case-control study in the Clinical Practice Research Datalink

Gastroesophageal reflux disease (GERD) causes local chronic inflammation that increases risks of Barrett⿿s esophagus (BE) and esophageal adenocarcinoma (EA), yet symptomatic GERD is absent in approximately half of all such patients. Obesity exacerbates GERD and is also a component of metabolic syndrome (MetS). We evaluated the hypothesis that MetS is a GERD-independent mechanism by which obesity is associated with increased risks of BE and EA using data from the UK Clinical Practice Research Datalink. BE cases (n = 10,215) and EA cases (n = 592) were each individually matched to five population controls based on age, sex, and general practice. MetS was defined as occurrence of at least three of the following: obesity, type 2 diabetes, hypertension, and high cholesterol. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression. MetS was marginally associated with BE (OR = 1.12, 95%CI 1.00⿿1.25). Similar effects were found for the individual component factors of obesity, hypertension, and high cholesterol. History of GERD modified the association (P-_{effect modification} <1E⿿5), with the MetS-BE association confined to patients without a history of GERD (OR = 1.33, 95%CI 1.12⿿1.58). No association between MetS and risk of EA was detected in the main or stratified analyses. In this large population-based case-control study, individuals with MetS had a marginally increased risk of BE in the absence of GERD. The systemic inflammatory state (MetS) may represent a reflux-independent inflammatory pathway that increases the risk of BE. MetS did not increase risk of EA in this study population.     

Mortality among patients with hypertension from 1995 to 2005: a population-based study

Background

We have reported that the prevalence of diagnosed hypertension increased by 60% from 1995 to 2005 in Ontario. In the present study, we asked whether this increase is explained by a decrease in the mortality rate.

Methods

We performed a population-based cohort study using linked administrative data for Ontario, a Canadian province with over 12 million residents. We identified prevalent cases of hypertension using a validated case-definition algorithm for hypertension, and we examined trends in mortality from 1995 to 2005 among adults aged 20 years and older with hypertension.

Results

The age-and sex-adjusted mortality among patients with hypertension decreased from 11.3 per 1000 people in 1995 to 9.6 per 1000 in 2005 (p < 0.001), which is a relative reduction of 15.5%. We found that the relative decrease in age-adjusted mortality was higher among men than among women (–22.2% v. –7.3%, p < 0.001).

Interpretation

Mortality rates among patients with hypertension have decreased. Along with an increasing incidence, decreased mortality rates may contribute to the increased prevalence of diagnosed hypertension. Sex-related discrepancies in the reduction of mortality warrant further investigation.High blood pressure is the leading risk factor for mortality around the world.^1,2 Over a decade ago, the Canadian Heart Health Survey reported that 42% of Canadian adults with hypertension were unaware that they had the condition and that only 16% of cases were treated and controlled.³ More recent studies in the United States⁴ and England⁵ have reported improved awareness, treatment and control among adults with hypertension. In addition, increased initiation of hypertensive medications among elderly patients⁶ and increased use of polytherapy for treating hypertension have been reported.⁷ Given that blood pressure control has been shown to reduce mortality, one might expect that enhanced awareness and treatment of hypertension has led to improvements in mortality among patients with this condition. Greater survival of patients with hypertension would contribute to an overall increase in the prevalence of hypertension.In another article in this issue of CMAJ, we report that the prevalence of diagnosed hypertension among adults increased by 60% from 1995 to 2005, which greatly surpassed prior projections for the developed world.⁸ Previous projections may have underestimated prevalence⁹ because researchers did not adequately account for the contribution of increased survival. Indeed, the increased prevalence cannot be explained by increased incidence alone, because the incidence of hypertension increased by 25.7% between 1997 and 2004 whereas prevalence increased by 35.5% during that same period. In the present study, our objective was to examine the mortality rates among patients with hypertension to determine whether declining mortality also contributed to the rising prevalence of hypertension.