Derivation and validation of predictive indices for 30-day mortality after coronary and valvular surgery in Ontario,Canada

Background:Coronary artery bypass grafting (CABG) and surgical aortic valve replacement (AVR) are the 2 most common cardiac surgery procedures in North America. We derived and externally validated clinical models to estimate the likelihood of death within 30 days of CABG, AVR or combined CABG + AVR.Methods:We obtained data from the CorHealth Ontario Cardiac Registry and several linked population health administrative databases from Ontario, Canada. We derived multiple logistic regression models from all adult patients who underwent CABG, AVR or combined CABG + AVR from April 2017 to March 2019, and validated them in 2 temporally distinct cohorts (April 2015 to March 2017 and April 2019 to March 2020).Results:The derivation cohorts included 13 435 patients who underwent CABG (30-d mortality 1.73%), 1970 patients who underwent AVR (30-d mortality 1.68%) and 1510 patients who underwent combined CABG + AVR (30-d mortality 3.05%). The final models for predicting 30-day mortality included 15 variables for patients undergoing CABG, 5 variables for patients undergoing AVR and 5 variables for patients undergoing combined CABG + AVR. Model discrimination was excellent for the CABG (c-statistic 0.888, optimism-corrected 0.866) AVR (c-statistic 0.850, optimism-corrected 0.762) and CABG + AVR (c-statistic 0.844, optimism-corrected 0.776) models, with similar results in the validation cohorts.Interpretation:Our models, leveraging readily available, multidimensional data sources, computed accurate risk-adjusted 30-day mortality rates for CABG, AVR and combined CABG + AVR, with discrimination comparable to more complex American and European models. The ability to accurately predict perioperative mortality rates for these procedures will be valuable for quality improvement initiatives across institutions.

Coronary artery bypass grafting (CABG) and surgical aortic valve replacement (AVR) are 2 of the most common cardiac surgical procedures in North America.¹ Accurate risk models of perioperative mortality for CABG and AVR are not only useful for operative decision-making,² but also valuable for quality improvement initiatives across surgeons and institutions.In North America, the most widely used 30-day mortality risk score is the Society of Thoracic Surgeons (STS)–Predicted Risk of Mortality tool, derived from more than 1000 hospitals in the United States and encompassing more than 50 variables.³ An ideal risk model should be built and validated on the patient population in which it will be applied. Although the STS–Predicted Risk of Mortality tool was derived from a large surgical population, regional differences in patient sociodemographics and health care delivery systems may preclude this model from performing optimally in the health system where cardiac surgery is publicly funded. Furthermore, collecting more than 50 variables is resource intensive and is not feasible for all institutions. Similar limitations apply to the EuroSCORE II, which was derived from a population-based cohort in Europe.⁴ Given these limitations, we developed a more parsimonious model using readily available, linked clinical and administrative data sets in Ontario, Canada, to efficiently and accurately calculate risk-adjusted 30-day mortality rates for the purpose of province-wide quality improvement after CABG, AVR and combined CABG + AVR.     

Diagnostic performance of chest radiography measurements for the assessment of cardiac chamber enlargement

Background:The cardiothoracic ratio (CTR) is commonly assessed on chest radiography for detection of cardiac chamber enlargement, but the traditional cutpoint of 0.5 has low specificity. We sought to evaluate the diagnostic accuracy of new measurement techniques for the detection of cardiac enlargement on chest radiographs.Methods:We obtained retrospective cross-sectional data on consecutive patients who underwent both chest radiography and cardiac magnetic resonance imaging (MRI) within a 14-day interval between 2006 and 2016 at a large academic hospital network. We established the presence of cardiac chamber enlargement using cardiac MRI as the reference standard. We evaluated the diagnostic performance of different techniques for measuring heart size and CTR on frontal chest radiographs.Results:Of 152 patients included, 81 (53%) were men and the mean age was 52 years. Maximum heart diameter had the highest area under the receiver operating characteristic curve for detection of cardiac enlargement (0.827, 95% confidence interval 0.760–0.894). In the subgroup of posteroanterior chest radiography studies (n = 101), a CTR cutpoint of 0.50 had only moderate sensitivity (72%) and specificity (72%). In men, a maximum heart diameter cutpoint of 15 cm had a sensitivity of 86% and a negative likelihood ratio of 0.24, and a cutpoint of 19 cm had a specificity of 100% and a positive likelihood ratio of infinity. In women, a maximum heart diameter cutpoint of 13 cm had a sensitivity of 91% and a negative likelihood ratio of 0.15, and a cutpoint of 17 cm had a specificity of 91% and a positive likelihood ratio of 3.5.Interpretation:A traditional CTR cutpoint of 0.5 has limited diagnostic value. Simple heart diameter measurements have higher diagnostic performance measures than CTR.

Cardiac chamber enlargement is important to identify, given that it is a predictor of poor outcomes and may reflect potentially treatable underlying disease.¹ Cardiac chamber size can be assessed using multiple imaging modalities, including chest radiography, echocardiography, computed tomography and cardiac magnetic resonance imaging (MRI).^2–4 Although cardiac MRI is considered the reference standard for the evaluation of cardiac size and function, it is rarely performed as an initial investigation because of its relatively high cost and limited availability.⁵ On the other hand, chest radiography is frequently performed as the initial imaging investigation for suspected pulmonary and cardiac disease, including in patients presenting with shortness of breath and chest pain.^6,7 Therefore, accurate and reproducible measures of cardiac enlargement on chest radiography would help to identify patients with underlying cardiac disease who might benefit from further investigation.Cardiac enlargement is frequently evaluated on chest radiography using the cardiothoracic ratio (CTR), which was originally described in 1919.⁸ Although this sign is an accepted and frequently used marker of cardiac enlargement, it has not been validated against cardiac MRI or other contemporary methods of objectively assessing cardiac chamber size. Some studies have shown that the CTR, as assessed using the originally described cutpoint of 0.5, has low specificity and diagnostic accuracy for cardiac enlargement, and therefore may be of limited clinical utility.^9–11 The purpose of this study was to evaluate new measurement techniques and cutpoints for the detection of cardiac chamber enlargement on chest radiography in comparison with MRI.     

Practice facilitation for improving cardiovascular care: secondary evaluation of a stepped wedge cluster randomized controlled trial using population-based administrative data

BackgroundPractice facilitation (PF), a multifaceted approach in which facilitators (external health care professionals) help family physicians to improve their adoption of best practices, has been highly successful. Improved Delivery of Cardiovascular Care (IDOCC) was an innovative PF trial designed to improve evidence-based care for people who have, or are at risk of, cardiovascular disease (CVD). The intervention was found to be ineffective as assessed by a patient-level composite score based on chart reviews from a subsample of patients (N = 5292). Here, we used population-based administrative data to examine IDOCC’s effect on CVD-related hospitalizations.MethodsIDOCC used a pragmatic, stepped wedge cluster randomized controlled design involving primary care providers recruited across Eastern Ontario, Canada. IDOCC’s effect on CVD-related hospitalizations was assessed in the 2 years of active intervention and post-intervention years. Marginal and mixed-effects regression analyses were used to account for the study design and to control for patient, physician, and practice characteristics. Secondary and subgroup analyses investigated robustness.ResultsOur sample included 262,996 patient/year observations representing 54,085 unique patients who had, or were at risk of, CVD, from 70 practices. There was a strong decreasing secular trend in CVD-related hospitalizations but no statistically significant effect of IDOCC. Relative to patients in the control condition, patients in the intervention condition were estimated to have 4 % lower odds of CVD-related hospitalizations (adjOR = 0.96, 99 % CI 0.83 to 1.11). The nonsignificant result persisted across robustness analyses.ConclusionsClinical outcomes from administrative databases were examined to form a more complete picture of the (in)effectiveness of a large-scale quality improvement intervention. IDOCC did not have a significant effect on CVD hospitalizations, suggesting that the results from the primary composite adherence score analysis were neither due to choice of outcome nor relatively short follow-up period.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00574808","term_id":"NCT00574808"}}NCT00574808, registered on 14 December 2007.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1547-2) contains supplementary material, which is available to authorized users.     

Effects of remote ischemic preconditioning in high-risk patients undergoing cardiac surgery (Remote IMPACT): a randomized controlled trial

Background:Remote ischemic preconditioning is a simple therapy that may reduce cardiac and kidney injury. We undertook a randomized controlled trial to evaluate the effect of this therapy on markers of heart and kidney injury after cardiac surgery.Methods:Patients at high risk of death within 30 days after cardiac surgery were randomly assigned to undergo remote ischemic preconditioning or a sham procedure after induction of anesthesia. The preconditioning therapy was three 5-minute cycles of thigh ischemia, with 5 minutes of reperfusion between cycles. The sham procedure was identical except that ischemia was not induced. The primary outcome was peak creatine kinase–myocardial band (CK-MB) within 24 hours after surgery (expressed as multiples of the upper limit of normal, with log transformation). The secondary outcome was change in creatinine level within 4 days after surgery (expressed as log-transformed micromoles per litre). Patient-important outcomes were assessed up to 6 months after randomization.Results:We randomly assigned 128 patients to remote ischemic preconditioning and 130 to the sham therapy. There were no significant differences in postoperative CK-MB (absolute mean difference 0.15, 95% confidence interval [CI] −0.07 to 0.36) or creatinine (absolute mean difference 0.06, 95% CI −0.10 to 0.23). Other outcomes did not differ significantly for remote ischemic preconditioning relative to the sham therapy: for myocardial infarction, relative risk (RR) 1.35 (95% CI 0.85 to 2.17); for acute kidney injury, RR 1.10 (95% CI 0.68 to 1.78); for stroke, RR 1.02 (95% CI 0.34 to 3.07); and for death, RR 1.47 (95% CI 0.65 to 3.31).Interpretation:Remote ischemic precnditioning did not reduce myocardial or kidney injury during cardiac surgery. This type of therapy is unlikely to substantially improve patient-important outcomes in cardiac surgery. Trial registration: ClinicalTrials.gov, no. {"type":"clinical-trial","attrs":{"text":"NCT01071265","term_id":"NCT01071265"}}NCT01071265.Each year, 2 million patients worldwide undergo cardiac surgery. For more than 25% of these patients, the surgery is complicated by myocardial infarction (MI) and/or acute kidney injury, both of which are strongly associated with morbidity and mortality.^1–3 Preventing MI and acute kidney injury after cardiac surgery would improve survival.An important cause of MI and acute kidney injury in patients undergoing cardiac surgery is ischemia–reperfusion injury.^4,5 This type of injury begins as ischemia, which is then exacerbated by a systemic inflammatory response upon restoration of organ perfusion.⁶ Remote ischemic preconditioning may mitigate ischemia–reperfusion damage. It is accomplished by inducing, before surgery, brief episodes of ischemia in a limb, which lead to widespread activation of endogenous cellular systems that may protect organs from subsequent severe ischemia and reperfusion.^7–9Small randomized controlled trials evaluating the efficacy of remote ischemic preconditioning have had mixed results.^10–17 Interpretation of their data is difficult because of small sample sizes and heterogeneity in the preconditioning procedures and patient populations (e.g., few trials have evaluated patients at high risk of organ injury and postoperative death). Whether remote ischemic preconditioning effectively mitigates ischemia–reperfusion injury therefore remains uncertain. We undertook the Remote Ischemic Preconditioning in Cardiac Surgery Trial (Remote IMPACT) to determine whether this procedure reduces myocardial and kidney injury. We proposed that a large trial to determine the effect on clinically important outcomes would be worthwhile only if a substantial effect on myocardial or kidney injury, or both, were observed in the current study.     

Multicomponent Interdisciplinary Group Intervention for Self-Management of Fibromyalgia: A Mixed-Methods Randomized Controlled Trial

BackgroundThis study evaluated the efficacy of the PASSAGE Program, a structured multicomponent interdisciplinary group intervention for the self-management of FMS.MethodsA mixed-methods randomized controlled trial (intervention (INT) vs. waitlist (WL)) was conducted with patients suffering from FMS. Data were collected at baseline (T₀), at the end of the intervention (T₁), and 3 months later (T₂). The primary outcome was change in pain intensity (0-10). Secondary outcomes were fibromyalgia severity, pain interference, sleep quality, pain coping strategies, depression, health-related quality of life, patient global impression of change (PGIC), and perceived pain relief. Qualitative group interviews with a subset of patients were also conducted. Complete data from T₀ to T₂ were available for 43 patients.ResultsThe intervention had a statistically significant impact on the three PGIC measures. At the end of the PASSAGE Program, the percentages of patients who perceived overall improvement in their pain levels, functioning and quality of life were significantly higher in the INT Group (73%, 55%, 77% respectively) than in the WL Group (8%, 12%, 20%). The same differences were observed 3 months post-intervention (Intervention group: 62%, 43%, 38% vs Waitlist Group: 13%, 13%, 9%). The proportion of patients who reported ≥50% pain relief was also significantly higher in the INT Group at the end of the intervention (36% vs 12%) and 3 months post-intervention (33% vs 4%). Results of the qualitative analysis were in line with the quantitative findings regarding the efficacy of the intervention. The improvement, however, was not reflected in the primary outcome and other secondary outcome measures.ConclusionThe PASSAGE Program was effective in helping FMS patients gain a sense of control over their symptoms. We suggest including PGIC in future clinical trials on FMS as they appear to capture important aspects of the patients’ experience.

Trial registration

International Standard Randomized Controlled Trial Number Register ISRCTN14526380     

Gender-based differences in physician payments within the fee-for-service system in Ontario: a retrospective,cross-sectional study

Background:Differences in physician income by gender have been described in numerous jurisdictions, but few studies have looked at a Canadian cohort with adjustment for confounders. In this study, we aimed to understand differences in fee-for-service payments to men and women physicians in Ontario.Methods:We conducted a cross-sectional analysis of all Ontario physicians who submitted claims to the Ontario Health Insurance Plan (OHIP) in 2017. For each physician, we gathered demographic information from the College of Physicians and Surgeons of Ontario registry. We compared differences in physician claims between men and women in the entire cohort and within each specialty using multivariable linear regressions, controlling for length of practice, specialty and practice location.Results:We identified a cohort of 30 167 physicians who submitted claims to OHIP in 2017, including 17 992 men and 12 175 women. When controlling for confounding variables in a linear mixed-effects regression model, annual physician claims were $93 930 (95% confidence interval $88 434 to $99 431) higher for men than for women. Women claimed 74% as much as men when adjusting for covariates. This discrepancy was present in nearly all specialty categories. Men claimed more than women throughout their careers, with the greatest gap 10–15 years into practice.Interpretation:We found a gender gap in fee-for-service claims in Ontario, with women claiming less than men overall and in nearly every specialty. Further work is required to understand the root causes of the gender pay gap.

A gender pay gap in physician incomes has been described across numerous jurisdictions.¹ Previous analyses have found income differences between women and men in the general physician population, among academic physicians and among physicians within the same specialty, ^2–8 and when controlling for years of experience, hours worked, geographic location, race and practice type.^9–13Although the difference in physician income between women and men is well described in the United States, fewer studies have looked at a Canadian cohort. An analysis of surgeons in Ontario found that female surgeons earned less per hour spent operating than male surgeons, and suggested that female physicians were more likely to perform less lucrative procedures than male physicians.¹⁴ A recent report released by the Ontario Medical Association highlighted income disparity between men and women physicians in Ontario, but did not provide a detailed breakdown by specialty.¹⁵ Transparent and detailed reporting on gender differences in physician payments can provide data to guide advocacy for greater pay equity.In this study, we aimed to describe payments to physicians across the province of Ontario by gender when controlling for specialty choice, career stage and physician demographics.     

Prospective validation of a 1-hour algorithm to rule-out and rule-in acute myocardial infarction using a high-sensitivity cardiac troponin T assay

Background:We aimed to prospectively validate a novel 1-hour algorithm using high-sensitivity cardiac troponin T measurement for early rule-out and rule-in of acute myocardial infarction (MI).Methods:In a multicentre study, we enrolled 1320 patients presenting to the emergency department with suspected acute MI. The high-sensitivity cardiac troponin T 1-hour algorithm, incorporating baseline values as well as absolute changes within the first hour, was validated against the final diagnosis. The final diagnosis was then adjudicated by 2 independent cardiologists using all available information, including coronary angiography, echocardiography, follow-up data and serial measurements of high-sensitivity cardiac troponin T levels.Results:Acute MI was the final diagnosis in 17.3% of patients. With application of the high-sensitivity cardiac troponin T 1-hour algorithm, 786 (59.5%) patients were classified as “rule-out,” 216 (16.4%) were classified as “rule-in” and 318 (24.1%) were classified to the “observational zone.” The sensitivity and the negative predictive value for acute MI in the rule-out zone were 99.6% (95% confidence interval [CI] 97.6%–99.9%) and 99.9% (95% CI 99.3%–100%), respectively. The specificity and the positive predictive value for acute MI in the rule-in zone were 95.7% (95% CI 94.3%–96.8%) and 78.2% (95% CI 72.1%–83.6%), respectively. The 1-hour algorithm provided higher negative and positive predictive values than the standard interpretation of highsensitivity cardiac troponin T using a single cut-off level (both p < 0.05). Cumulative 30-day mortality was 0.0%, 1.6% and 1.9% in patients classified in the rule-out, observational and rule-in groups, respectively (p = 0.001).Interpretation:This rapid strategy incorporating high-sensitivity cardiac troponin T baseline values and absolute changes within the first hour substantially accelerated the management of suspected acute MI by allowing safe rule-out as well as accurate rule-in of acute MI in 3 out of 4 patients. Trial registration: ClinicalTrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT00470587","term_id":"NCT00470587"}}NCT00470587Acute myocardial infarction (MI) is a major cause of death and disability worldwide. As highly effective treatments are available, early and accurate detection of acute MI is crucial.^1–5 Clinical assessment, 12-lead electrocardiography (ECG) and measurement of cardiac troponin levels form the pillars for the early diagnosis of acute MI in the emergency department. Major advances have recently been achieved by the development of more sensitive cardiac troponin assays.^6–15 High-sensitivity cardiac troponin assays, which allow measurement of even low concentrations of cardiac troponin with high precision, have been shown to largely overcome the sensitivity deficit of conventional cardiac troponin assays within the first hours of presentation in the diagnosis of acute MI.^6–15 These studies have consistently shown that the classic diagnostic interpretation of cardiac troponin as a dichotomous variable (troponin-negative and troponin-positive) no longer seems appropriate, because the positive predictive value for acute MI of being troponin-positive was only about 50%.^6–15 The best way to interpret and clinically use high-sensitivity cardiac troponin levels in the early diagnosis of acute MI is still debated.^3,5,7In a pilot study, a novel high-sensitivity cardiac troponin T 1-hour algorithm was shown to allow accurate rule-out and rule-in of acute MI within 1 hour in up to 75% of patients.¹¹ This algorithm is based on 2 concepts. First, high-sensitivity cardiac troponin T is interpreted as a quantitative variable where the proportion of patients who have acute MI increases with increasing concentrations of cardiac troponin T.^6–15 Second, early absolute changes in the concentrations within 1 hour provide incremental diagnostic information when added to baseline levels, with the combination acting as a reliable surrogate for late concentrations at 3 or 6 hours.^6–15 However, many experts remained skeptical regarding the safety of the high-sensitivity cardiac troponin T 1-hour algorithm and its wider applicability.¹⁶ Accordingly, this novel diagnostic concept has not been adopted clinically to date. Because the clinical application of this algorithm would represent a profound change in clinical practice, prospective validation in a large cohort is mandatory before it can be considered for routine clinical use. The aim of this multicentre study was to prospectively validate the high-sensitivity cardiac troponin T 1-hour algorithm in a large independent cohort.     

Use of standardized brief geriatric evaluation compared with routine care in general practice for preventing functional decline: a pragmatic cluster-randomized trial

Background:Although assessment of geriatric syndromes is increasingly encouraged in older adults, little evidence exists to support its systematic use by general practitioners (GPs). The aim of this study was to determine whether a systematic geriatric evaluation performed by GPs can prevent functional decline.Methods:We conducted a controlled, open-label, pragmatic cluster-randomized trial in 42 general practices in Switzerland. Participating GPs were expected to enrol an average of 10 community-dwelling adults (aged ≥ 75 yr) who understood French, and had visited their GP at least twice in the previous year. The intervention consisted of yearly assessment by the GP of 8 geriatric syndromes with an associated tailored management plan according to assessment results, compared with routine care. Our primary outcomes were the proportion of patients who lost at least 1 instrumental activity of daily living (ADL) and the proportion who lost at least 1 basic ADL, over 2 years. Our secondary outcomes were quality-of-life scores, measured using the older adult module of the World Health Organization Quality of Life Instrument, and health care use.Results:Forty-two GPs recruited 429 participants (63% women) with a mean age of 82.5 years (standard deviation 4.8 yr) at time of recruitment. Of these, we randomly assigned 217 participants to the intervention and 212 to the control arm. The proportion of patients who lost at least 1 instrumental ADL in the intervention and control arms during the course of the study was 43.6% and 47.6%, respectively (risk difference −4.0%, 95% confidence interval [CI] −14.9% to 6.7%, p = 0.5). The proportion of patients who lost at least 1 basic ADL was 12.4% in the intervention arm and 16.9% in the control arm (risk difference −5.1%, 95% CI −14.3% to 4.1%, p = 0.3).Interpretation:A yearly geriatric evaluation with an associated management plan, conducted systematically in GP practices, does not significantly lessen functional decline among community-dwelling, older adult patients, compared with routine care.Trial registration:ClinicalTrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT02618291","term_id":"NCT02618291"}}NCT02618291.

The World Health Organization has defined healthy aging as the process of developing and maintaining functional ability that enables well-being in older age.¹ Functional ability is often measured by an individual’s ability to perform activities of daily living (ADLs) without assistance. Geriatric syndromes, corresponding to multifactorial, chronic conditions, can impair physical and mental capacities,^2–4 and are directly associated with functional decline.⁵ If recognized early, adapted preventive measures and management strategies can be started to limit functional decline.^6–8 Interventions that have been shown to delay functional decline include comprehensive geriatric assessment, regular home visits and physical therapy.^6,8,9 Comprehensive geriatric assessment consists of a “multidisciplinary diagnostic and treatment process that identifies medical, psychosocial, and functional capabilities of older adults to develop a coordinated plan to maximize overall health with ageing.”¹⁰ These assessments are usually performed by specialized geriatric teams for patients who have already been identified as frail or in the context of rehabilitation. However, most older patients see only their general practitioner (GP) and are not provided a comprehensive geriatric assessment, considering that this is a lengthy process that is often beyond the scope of a usual primary care consultation. A recent systematic review of comprehensive geriatric assessment in primary care found only 4 studies conducted in this setting,¹¹ showing mixed effects on clinical outcomes. Only 1 study assessed functional ability, and it showed no impact in this context.¹²In primary care, it may be more beneficial to use shorter screening tools.^13–19 Previous studies using shorter tools adapted for primary care have failed to show a difference for patients compared with routine care.^17,18 These interventions usually targeted patients who were already identified as frail or with a predefined number of problems.^17,18,20In contrast, our Active Geriatric Evaluation (AGE) tool targets all patients aged 75 and older. This clinical tool can be easily integrated to clinical encounters in GP practices, without the need for additional organizational changes. For this study, we aimed to determine whether the AGE tool, specifically designed for GPs and consisting of a brief assessment of the most relevant geriatric syndromes combined with management plans, could slow functional decline in older patients.     

Evaluation of the relative virulence of novel SARS-CoV-2 variants: a retrospective cohort study in Ontario,Canada

Background:Between February and June 2021, the initial wild-type strains of SARS-CoV-2 were supplanted in Ontario, Canada, by new variants of concern (VOCs), first those with the N501Y mutation (i.e., Alpha/B1.1.17, Beta/B.1.351 and Gamma/P.1 variants) and then the Delta/B.1.617 variant. The increased transmissibility of these VOCs has been documented, but knowledge about their virulence is limited. We used Ontario’s COVID-19 case data to evaluate the virulence of these VOCs compared with non-VOC SARS-CoV-2 strains, as measured by risk of hospitalization, intensive care unit (ICU) admission and death.Methods:We created a retrospective cohort of people in Ontario who tested positive for SARS-CoV-2 and were screened for VOCs, with dates of test report between Feb. 7 and June 27, 2021. We constructed mixed-effect logistic regression models with hospitalization, ICU admission and death as outcome variables. We adjusted models for age, sex, time, vaccination status, comorbidities and pregnancy status. We included health units as random intercepts.Results:Our cohort included 212 326 people. Compared with non-VOC SARS-CoV-2 strains, the adjusted elevation in risk associated with N501Y-positive variants was 52% (95% confidence interval [CI] 42%–63%) for hospitalization, 89% (95% CI 67%–117%) for ICU admission and 51% (95% CI 30%–78%) for death. Increased risk with the Delta variant was more pronounced at 108% (95% CI 78%–140%) for hospitalization, 235% (95% CI 160%–331%) for ICU admission and 133% (95% CI 54%–231%) for death.Interpretation:The increasing virulence of SARS-CoV-2 VOCs will lead to a considerably larger, and more deadly, pandemic than would have occurred in the absence of the emergence of VOCs.

Novel SARS-CoV-2 variants of concern (VOCs), including viral lineages carrying the N501Y (Alpha/B.1.1.7) or both the N501Y and E484K mutations (Beta/B.1.351 and Gamma/P.1), were first identified in Ontario, Canada, in December 2020.¹ Although initially uncommon in Ontario, these VOCs outcompeted earlier SARS-CoV-2 lineages and, as of late April 2021, were responsible for almost all new infections in Ontario, with Alpha the most prevalent lineage.¹ In April 2021, the B.1.617.2 variant, now known as Delta under the revised nomenclature from the World Health Organization, emerged in the province, outcompeted earlier VOCs and, by July 2021, represented most infections in the province.^2,3This serial replacement by emerging variants reflects progressively higher effective reproduction numbers that allow novel variants to outcompete previously dominant strains in the face of identical measures to control spread of infection.^4–6 However, VOCs are also concerning because emerging evidence points to increased virulence, with increased risk of hospitalization, intensive care unit (ICU) admission and death, after adjustment for age and other predictive factors among patients with VOC infections.^7–10 Although the increased virulence of strains with the N501Y mutation relative to strains that lack this mutation has been described,^7–9 only limited information is available on the virulence of infection with the Delta variant, relative to earlier N501Y-positive VOCs (i.e., Alpha, Beta and Gamma).^10–12 Our objectives were to evaluate the virulence of N501Y-positive variants relative to earlier SARS-CoV-2 lineages and to evaluate the virulence of the Delta variant of SARS-CoV-2 relative to N501Y-positive VOCs using Ontario’s COVID-19 case data.     

Predictors of early and late stroke following cardiac surgery

Background:

Much is known about the short-term risks of stroke following cardiac surgery. We examined the rate and predictors of long-term stroke in a cohort of patients who underwent cardiac surgery.

Methods:

We obtained linked data for patients who underwent cardiac surgery in the province of Ontario between 1996 and 2006. We analyzed the incidence of stroke and death up to 2 years postoperatively.

Results:

Of 108 711 patients, 1.8% (95% confidence interval [CI] 1.7%–1.9%) had a stroke perioperatively, and 3.6% (95% CI 3.5%–3.7%) had a stroke within the ensuing 2 years. The strongest predictors of both early and late stroke were advanced age (≥ 65 year; adjusted hazard ratio [HR] for all stroke 1.9, 95% CI 1.8–2.0), a history of stroke or transient ischemic attack (adjusted HR 2.1, 95% CI 1.9–2.3), peripheral vascular disease (adjusted HR 1.6, 95% CI 1.5–1.7), combined coronary bypass grafting and valve surgery (adjusted HR 1.7, 95% CI 1.5–1.8) and valve surgery alone (adjusted HR 1.4, 95% CI 1.2–1.5). Preoperative need for dialysis (adjusted odds ratio [OR] 2.1, 95% CI 1.6–2.8) and new-onset postoperative atrial fibrillation (adjusted OR 1.5, 95% CI 1.3–1.6) were predictors of only early stroke. A CHADS₂ score of 2 or higher was associated with an increased risk of stroke or death compared with a score of 0 or 1 (19.9% v. 9.3% among patients with a history of atrial fibrillation, 16.8% v. 7.8% among those with new-onset postoperative atrial fibrillation and 14.8% v. 5.8% among those without this condition).

Interpretation:

Patients who had cardiac surgery were at highest risk of stroke in the early postoperative period and had continued risk over the ensuing 2 years, with similar risk factors over these periods. New-onset postoperative atrial fibrillation was a predictor of only early stroke. The CHADS₂ score predicted stroke risk among patients with and without atrial fibrillation.Stroke remains a devastating complication following cardiac surgery, with substantial functional and economic impact.^1–3 Stroke research in cardiac surgery has focused on the immediate postoperative period;^4–9 however, most patients undergoing cardiac surgery have conditions such as hypertension, diabetes and atrial fibrillation, which place them at long-term risk of stroke.Early and late outcomes among patients undergoing cardiac surgery could be improved if the risk of postoperative stroke was defined and predictors of stroke identified. With this information, clinicians could optimize medical therapy for stroke risk factors such as hypertension,^10,11 improve the evidence-based use of oral anticoagulation in patients with atrial fibrillation and evaluate intraoperative surgical strategies (e.g., removal of the left atrial appendage¹²) in patients whose clinical characteristics predict an increased risk of stroke. We examined the rate and predictors of long-term stroke within 2 years after cardiac surgery.     

Preterm birth and stillbirth rates during the COVID-19 pandemic: a population-based cohort study

BACKGROUND:Conflicting reports have emerged for rates of preterm births and stillbirths during the COVID-19 pandemic. Most of these reports did not account for natural variation in these rates. We aimed to evaluate variations in preterm birth and stillbirth rates before and during the COVID-19 pandemic in Ontario, Canada.METHODS:We conducted a retrospective cohort study using linked population health administrative databases of pregnant people giving birth in any hospital in Ontario between July 2002 and December 2020. We calculated preterm birth and stillbirth rates. We assessed preterm birth at 22–28, 29–32 and 33–36 weeks’ gestation, and stillbirths at term and preterm gestation. We used Laney control P′ charts for the 18-year study period (6-mo observation periods) and interrupted time-series analyses for monthly rates for the most recent 4 years.RESULTS:We evaluated 2 465 387 pregnancies, including 13 781 that resulted in stillbirth. The mean preterm birth rate for our cohort was 7.96% (range 7.32%–8.59%). From January to December 2020, we determined that the preterm birth rate in Ontario was 7.87%, with no special cause variation. The mean stillbirth rate for the cohort was 0.56% (range 0.48%–0.70%). From January to December 2020, the stillbirth rate was 0.53%, with no special cause variation. We did not find any special cause variation for preterm birth or stillbirth subgroups. We found no changes in slope or gap between prepandemic and pandemic periods using interrupted time-series analyses.INTERPRETATION:In Ontario, Canada, we found no special cause variation (unusual change) in preterm birth or stillbirth rates, overall or by subgroups, during the first 12 months of the COVID-19 pandemic compared with the previous 17.5 years.

Preterm birth (birth before 37 weeks’ gestation) is a leading cause of mortality and morbidities in the neonatal period,¹ childhood and adulthood.² Stillbirth has devastating consequences for families.³ The causes of both preterm birth and stillbirth are multifactorial. During the pandemic, reports described reductions in preterm birth rates in Denmark,⁴ the Netherlands,⁵ Ireland⁶ and the United States.⁷ At the same time, increases in stillbirth rates were reported from the United Kingdom,⁸ Italy,⁹ Nepal¹⁰ and India,¹¹ with or without changes in rates of preterm births. Meta-analyses have emerged with differing conclusions.^12,13 Some speculated reasons for reductions in preterm births included reductions in physical activity during pregnancy, reduced stress related to work–life balance, less exposure to infection, fewer medical interventions, reduced travel and pollution,¹⁴ and improved hygiene and rest. Proposed reasons for increases in preterm birth rates include higher stress due to worry about the pandemic, employment or financial challenges, home schooling and reduced maternity services.¹⁵ Less stringent fetal surveillance from reduced attendance at medical appointments for fear of infection, cancellation of face-to-face appointments and reduced staffing for maternity services are possible reasons for increased rates of stillbirths. Thus, it is important to evaluate preterm births and stillbirths simultaneously to understand the true impact.¹⁶Some previous reports compared preterm birth and stillbirth rates during the pandemic to similar time periods in the past few years. However, within a jurisdiction, these rates are known to fluctuate between epochs¹⁷ and, thus, it is preferable to evaluate rates over longer periods to establish whether observed variations are usual (common cause variation) or unusual (special cause variation). Our objective was to evaluate whether the COVID-19 pandemic affected preterm birth or stillbirth rates in Ontario by comparing rates for the early COVID-19 pandemic time period with rates from the previous 17.5 years to identify patterns of variation.     

Prevention of catheter-related bladder discomfort – pudendal nerve block with ropivacaine versus intravenous tramadol: study protocol for a randomized controlled trial

BackgroundCatheter-related bladder discomfort (CRBD) is a common distressing symptom complex during the postoperative period, especially after urologic procedures with a relatively greater size urinary catheter. In this study, we will enroll male patients undergoing elective prostate surgery with urinary catheterization under general anesthesia, and we will compare the efficacy of pudendal nerve block (PNB) and intravenous tramadol in CRBD prevention.Methods/designThis trial is a prospective, randomized controlled trial that will test the superiority of bilateral PNB with 0.33 % ropivacaine compared with intravenous tramadol 1.5 mg/kg for CRBD prevention. A total of 94 male patients undergoing elective prostate surgery with urinary catheterization after anesthesia induction will be randomized to receive either bilateral PNB with 0.33 % ropivacaine (the PNB group) or intravenous tramadol 1.5 mg/kg (the tramadol group) after the completion of surgery. The primary outcome is the incidence of CRBD. The most important secondary outcome is the severity of postoperative CRBD, and other secondary outcomes include Numeric Rating Scale (NRS) score for postoperative pain; incidence of postoperative side effects such as postoperative nausea/vomiting, sedation, dizziness, and dry mouth; postoperative requirement for tramadol as a rescue treatment for CRBD and sufentanil as a rescue analgesic for postoperative pain; and NRS score for acceptance of an indwelling urinary catheter.DiscussionThis trial is planned to test the superiority of PNB with 0.33 % ropivacaine compared with intravenous tramadol 1.5 mg/kg. It may provide a basis for a new clinical practice for the prevention of CRBD.

Trial registration

ClinicalTrials.gov identifier {"type":"clinical-trial","attrs":{"text":"NCT02683070","term_id":"NCT02683070"}}NCT02683070. Registered on 11 February 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1575-y) contains supplementary material, which is available to authorized users.     

Measurement of Cardiac Index by Transpulmonary Thermodilution Using an Implanted Central Venous Access Port: A Prospective Study in Patients Scheduled for Oncologic High-Risk Surgery

Background

Transpulmonary thermodilution allows the measurement of cardiac index for high risk surgical patients. Oncologic patients often have a central venous access (port-a-catheter) for chronic treatment. The validity of the measurement by a port-a-catheter of the absolute cardiac index and the detection of changes in cardiac index induced by fluid challenge are unknown.

Methods

We conducted a monocentric prospective study. 27 patients were enrolled. 250 ml colloid volume expansions for fluid challenge were performed during ovarian cytoreductive surgery. The volume expansion-induced changes in cardiac index measured by transpulmonary thermodilution by a central venous access (CIcvc) and by a port-a-catheter (CIport) were recorded.

Results

23 patients were analyzed with 123 pairs of measurements. Using a Bland and Altman for repeated measurements, the bias (lower and upper limits of agreement) between CIport and CIcvc was 0.14 (−0.59 to 0.88) L/min/m². The percentage error was 22%. The concordance between the changes in CIport and CIcvc observed during volume expansion was 92% with an r = 0.7 (with exclusion zone). No complications (included sepsis) were observed during the follow up period.

Conclusions

The transpulmonary thermodilution by a port-a-catheter is reliable for absolute values estimation of cardiac index and for measurement of the variation after fluid challenge.

Trial Registration

clinicaltrials.gov NCT02063009     

Validation of Cell-Cycle Arrest Biomarkers for Acute Kidney Injury after Pediatric Cardiac Surgery

Background

The lack of early biomarkers for acute kidney injury (AKI) seriously inhibits the initiation of preventive and therapeutic measures for this syndrome in a timely manner. We tested the hypothesis that insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinases-2 (TIMP-2), both inducers of G1 cell cycle arrest, function as early biomarkers for AKI after congenital heart surgery with cardiopulmonary bypass (CPB).

Methods

We prospectively studied 51 children undergoing cardiac surgery with CPB. Serial urine samples were analyzed for [TIMP-2]•[IGFBP7]. The primary outcome measure was AKI defined by the pRIFLE criteria within 72 hours after surgery.

Results

12 children (24%) developed AKI within 1.67 (SE 0.3) days after surgery. Children who developed AKI after cardiac surgery had a significant higher urinary [TIMP-2]•[IGFBP7] as early as 4 h after the procedure, compared to children who did not develop AKI (mean of 1.93 ((ng/ml)²/1000) (SE 0.4) vs 0.47 ((ng/ml)²/1000) (SE 0.1), respectively; p<0.05). Urinary [TIMP-2]•[IGFBP7] 4 hours following surgery demonstrated an area under the receiver-operating characteristic curve of 0.85. Sensitivity was 0.83, and specificity was 0.77 for a cutoff value of 0.70 ((ng/ml)²/1000).

Conclusions

Urinary [TIMP-2]•[IGFBP7] represent sensitive, specific, and highly predictive early biomarkers for AKI after surgery for congenital heart disease.

Trial Registration

www.germanctr.de/, DRKS00005062     

The relevance,biases, and importance of digitising opportunistic non-standardised collections: A case study in Iberian harvestmen fauna with BOS Arthropod Collection datasets (Arachnida,Opiliones)

In this study, we analyse the relevance of harvestmen distribution data derived from opportunistic, unplanned, and non-standardised collection events in an area in the north of the Iberian Peninsula. Using specimens deposited in the BOS Arthropod Collection at the University of Oviedo, we compared these data with data from planned, standardised, and periodic collections with pitfall traps in several locations in the same area. The Arthropod Collection, begun in 1977, includes specimens derived from both sampling types, and its recent digitisation allows for this type of comparative analysis. Therefore, this is the first data-paper employing a hybrid approach, wherein subset metadata are described alongside a comparative analysis. The full dataset can be accessed through Spanish GBIF IPT at http://www.gbif.es:8080/ipt/archive.do?r=Bos-Opi, and the metadata of the unplanned collection events at http://www.gbif.es:8080/ipt/resource.do?r=bos-opi_unplanned_collection_events. We have mapped the data on the 18 harvestmen species included in the unplanned collections and provided records for some species in six provinces for the first time. We have also provided the locations of Phalangium opilio in eight provinces without published records. These results highlight the importance of digitising data from unplanned biodiversity collections, as well as those derived from planned collections, especially in scarcely studied groups and areas.     

Predicting death in home care users: derivation and validation of the Risk Evaluation for Support: Predictions for Elder-Life in the Community Tool (RESPECT)

BACKGROUND:Prognostication tools that report personalized mortality risk and survival could improve discussions about end-of-life and advance care planning. We sought to develop and validate a mortality risk model for older adults with diverse care needs in home care using self-reportable information — the Risk Evaluation for Support: Predictions for Elder-Life in the Community Tool (RESPECT).METHODS:Using a derivation cohort that comprised adults living in Ontario, Canada, aged 50 years and older with at least 1 Resident Assessment Instrument for Home Care (RAI-HC) record between Jan. 1, 2007, and Dec. 31, 2012, we developed a mortality risk model. The primary outcome was mortality 6 months after a RAI-HC assessment. We used proportional hazards regression with robust standard errors to account for clustering by the individual. We validated this algorithm for a second cohort of users of home care who were assessed between Jan. 1 and Dec. 31, 2013. We used Kaplan–Meier survival curves to estimate the observed risk of death at 6 months for assessment of calibration and median survival. We constructed 61 risk groups based on incremental increases in the estimated median survival of about 3 weeks among adults at high risk and 3 months among adults at lower risk.RESULTS:The derivation and validation cohorts included 435 009 and 139 388 adults, respectively. We identified a total of 122 823 deaths within 6 months of a RAI-HC assessment in the derivation cohort. The mean predicted 6-month mortality risk was 10.8% (95% confidence interval [CI] 10.7%–10.8%) and ranged from 1.54% (95% CI 1.53%–1.54%) in the lowest to 98.1% (95% CI 98.1%–98.2%) in the highest risk group. Estimated median survival spanned from 28 days (11 to 84 d at the 25th and 75th percentiles) in the highest risk group to over 8 years (1925 to 3420 d) in the lowest risk group. The algorithm had a c-statistic of 0.753 (95% CI 0.750–0.756) in our validation cohort.INTERPRETATION:The RESPECT mortality risk prediction tool that makes use of readily available information can improve the identification of palliative and end-of-life care needs in a diverse older adult population receiving home care.

Most people in high-income countries die of causes with progressive, predictable trajectories of decline.^1–4 Since 2000, the 3 leading causes of death in Canada — accounting for 55% of all deaths — have been cancer, heart disease and stroke.¹ Other leading causes of death, such as dementia and chronic lower respiratory diseases, also share signs and symptoms of senescence that are common across chronic diseases, including deterioration of physical and cognitive function, as well as an increased need for assistance.Despite the predictable nature of most deaths, many Canadian residents who are at the end of life do not receive adequate home-based supports.⁵ In Ontario — the largest province in Canada with more than 14 million residents and the setting of this study — only 40% of decedents receive formal home care, and less than 20% receive a physician home visit in their last year of life.^6,7 Even among those who had received palliative and end-of-life care, the start of service was often too close to death and failed to have a positive impact on the quality of life in those last months.⁸ The lack of available and accurate prognostic information is a key challenge. There are few existing tools that can be used to inform palliative care planning for the general population of older adults who live in the community and in people without cancer.⁹ Other barriers to accurate prognostic estimates include clinicians’ reluctance or lack of time and existing prognostication tools’ reliance on complex or specialized inputs, such as laboratory data and previous health care use. As a result, many older and frail adults do not receive timely palliative care and do not have an advance care plan.^6,10–13Our primary objective was to develop and validate a model for predicting mortality risk among the general population of community-dwelling adults with and without cancer that spans an actionable period for end-of-life planning (5 yr to imminent death). The variables included in our prognostication model — the Risk Evaluation for Support: Predictions for Elder-life in the Community Tool (RESPECT) — were prespecified to include exposures that could be self-reported by patients and their caregivers, including family members.     

Low-dose whole thorax radiation therapy for COVID-19 pneumonia: inpatient onboarding process for a randomized controlled trial

BackgroundThe mortality of the SARS-CoV-2 virus (COVID-19) has been associated with a pulmonary inflammatory response resulting in hypoxemia and rapid clinical decline. PREVENT is an ongoing prospective multicenter Phase II randomized controlled trial where patients hospitalized with COVID-19 pneumonia are randomized to low dose radiation therapy (RT) versus control (clinicaltrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT04466683","term_id":"NCT04466683"}}NCT04466683). We describe the inpatient onboarding process of the center contributing the largest number of patients to this trial.Materials and methodsCOVID-19 hospital admissions were attained by the clinical research manager and radiation oncologist daily. Text message contact was made with infectious disease, critical care, and nursing staff with reciprocal discussion of the trial protocol and approval for virtual consulting of the patient. Witnessed informed consent was obtained first by telephone and later in person. Simulation and treatment (performed without a computer plan) was performed on a linear accelerator with one personal protective equipment-protected therapist moving in and out of the treatment room, and a second therapist manning the console. Following on-site dose calculation by physics, the radiation oncologist approved the fields prior to treatment delivery.ResultsBetween August 28, 2020 and October 6, 2020, the first 10 enrolled patients on this multicenter trial were randomized and treated at our institution; no team member (research staff, radiation oncology) contracted COVID-19 while employing this protocol.ConclusionThis represents the first published protocol to address efficient and safe recruitment of COVID-19 patients for a radiation oncology trial, serving as a model for conducting recruitment of COVID-19 patients for clinical trials.     

Factors associated with consent for organ donation: a retrospective population-based study

Background:Optimizing the approach to and consent of potential organ donors maximizes patient autonomy and the availability of organs for transplants. We set out to identify modifiable factors associated with donation consent.Methods:We conducted a retrospective cohort study of consecutive adults (≥ 18 yr) referred for organ donation in Ontario between April 2013 and June 2019. We analyzed patient clinical data and demographics, data on substitute decision-makers and characteristics of the donation consent approach. Study outcomes were consent for organ donation and approach rate. We evaluated independent associations between consent and approach-and system-level factors.Results:We identified 34 837 referrals for organ donation, of which 6548 (18.8%) substitute decision-makers were approached for consent. Of these, 3927 (60.0% of approaches) consented for organ donation and 1883 (48.0% of consents) patients proceeded to be organ donors. The most common reason substitute decision-makers were not approached for consent in a case with donation potential was a late referral by the health care team (45.2%). Modifiable factors independently associated with consent included a telephone approach for consent (adjusted odds ratio [OR] 0.46, 95% confidence interval [CI] 0.35–0.58) and a collaborative approach by a physician and donation coordinator (adjusted OR 1.26, 95% CI 1.01–1.59).Interpretation:Consent for organ donation was associated with several modifiable factors. Organizations should target interventions to ensure timely referrals to organ donation organizations, increase in-person consent approaches and increase physician participation in the approach process.

Many people die on transplant waiting lists because the demand for organs outstrips supply. Almost 4500 people are on organ transplant waiting lists in Canada. Despite public support for organ donation across Canada,¹ donation rates vary between 8.8 and 21.2 donors per million population, ² and a substantial pool of potential donors is not being realized. ^2,3 The identification, referral and approach of potential donors can be facilitated by policy, legislation and best practices, ^3,4 although the efficacy of interventions is variable across jurisdictions.^5,6 Some comprehensive interventions to increase donor numbers have not changed consent rates,⁷ suggesting that the consent approach process may be a target for improvement.Substitute decision-makers play an important role in the organ donation process, even in jurisdictions with donation consent registries or opt-out consent systems. Substitute decision-makers are almost always asked permission for organ donation, even when there is a registered donation consent,⁸ and their consent rates vary widely.⁹ Substitute decision-makers faced with consent decisions often do so in emotionally charged circumstances, and many do not know the explicit wishes of the patient.¹⁰ Given this context, the process of obtaining consent and the supports provided may have a substantial impact on the decision. Practices have been identified that improve consent rates from substitute decision-makers,¹¹ and these are routinely performed by large, high-performing organ donation organizations. Several epidemiological studies have identified nonmodifiable factors associated with donation consent (e.g., race, age, socioeconomic status and education).^12–15 The persistent variability in consent rates suggests that other modifiable factors may influence a substitute decision-maker’s decision to consent.We aimed to identify modifiable approach-and system-level factors that were associated with positive consent for organ donation in Ontario, Canada.