Comparison of Health Behaviour Mortality Hazards in Canada and the United States

Introduction National health surveys, available in over 100 countries, are the most common data used for health behaviour surveillance and are increasingly being linked to individual-level health outcomes. We propose that improved health behaviour hazard estimates can be obtained from pooled international population health surveys linked to outcome data. Objectives and Approach The objective of this study was to compare smoking, alcohol, diet and physical activity all-cause mortality hazards in Canada and the United States using individual-level, linked population health survey data and common model specifications. The Canadian Community Health Survey (CCHS) (2003-2007) and the United States National Health Interview Survey (NHIS) (2000, 2005) linked to individual-level mortality outcomes with follow up to December 31, 2011 were used. Variable definitions consistent across the CCHS and NHIS were developed and used to estimate country-specific mortality hazards with sex-specific Cox proportional hazard models, including health behaviours, sociodemographic indicators and proximal factors including disease history. Results A total of 296,407 respondents and 1,813,884 million person-years of follow-up from the CCHS and 62,226 respondents and 497,909 person-years from the NHIS were included. Hazards of smoking, alcohol consumption, diet and physical activity in Canada and the United States are of similar magnitude and direction, with similar dose response relationships. The largest health behaviour mortality hazards were associated with female heavy smokers in both Canada (HR: 3.36, 95% CI: 2.86, 3.95) and the United States (Female HR: 2.63, 95% CI: 2.11, 3.27), compared to non-smokers. Conclusion/Implications Health behaviour mortality hazards are comparable in Canada and the United States, supporting the use of hazards obtained from pooled analyses for population heath. These hazards can replace those obtained from independent epidemiology studies that are often incompletely adjusted, rarely population-based and often not generalizable to the population of interest

The risk of stroke and stroke type in patients with atrial fibrillation and chronic kidney disease

Background: Atrial fibrillation (AF) and chronic kidney disease (CKD) are known to increase the risk of stroke. Objectives: We set out to examine the risk of stroke by kidney function and albuminuria in patients with and without AF. Design: Retrospective cohort study. Settings: Ontario, Canada. Participants: A total of 736 666 individuals (>40 years) from 2002 to 2015. Measurements: New-onset AF, albumin-to-creatinine ratio (ACR), and an estimated glomerular filtration rate (eGFR). Methods: A total of 39 120 matched patients were examined for the risk of ischemic, hemorrhagic, or any stroke event, accounting for the competing risk of all-cause mortality. Interaction terms for combinations of ACR/eGFR and the outcome of stroke with and without AF were examined. Results: In a total of 4086 (5.2%) strokes (86% ischemic), the presence of AF was associated with a 2-fold higher risk for any stroke event and its subtypes of ischemic and hemorrhagic stroke. Across eGFR levels, the risk of stroke was 2-fold higher with the presence of AF except for low levels of eGFR (eGFR < 30 mL/min/1.73 m2, hazard ratio [HR]: 1.38, 95% confidence interval [CI]: 0.99-1.92). Similarly across ACR levels, the risk of stroke was 2-fold higher except for high levels of albuminuria (ACR > 30 mg/g, HR: 1.61, 95% CI: 1.31-1.99). The adjusted risk of stroke with AF differed by combinations of ACR and eGFR categories (interaction P value = .04) compared with those without AF. Both stroke types were more common in patients with AF, and ischemic stroke rates differed significantly by eGFR and ACR categories. Limitations: Medication information was not included. Conclusions: Patients with CKD and AF are at a high risk of total, ischemic, and hemorrhagic strokes; the risk is highest with lower eGFR and higher ACR and differs based on eGFR and the degree of ACR

Comparison of mortality hazard ratios associated with health behaviours in Canada and the United States:a population-based linked health survey study

Background Modern health surveillance and planning requires an understanding of how preventable risk factors impact population health, and how these effects vary between populations. In this study, we compare how smoking, alcohol consumption, diet and physical activity are associated with all-cause mortality in Canada and the United States using comparable individual-level, linked population health survey data and identical model specifications. Methods The Canadian Community Health Survey (CCHS) (2003–2007) and the United States National Health Interview Survey (NHIS) (2000, 2005) linked to individual-level mortality outcomes with follow up to December 31, 2011 were used. Consistent variable definitions were used to estimate country-specific mortality hazard ratios with sex-specific Cox proportional hazard models, including smoking, alcohol, diet and physical activity, sociodemographic indicators and proximal factors including disease history. Results A total of 296,407 respondents and 1,813,884 million person-years of follow-up from the CCHS and 58,232 respondents and 497,909 person-years from the NHIS were included. Absolute mortality risk among those with a ‘healthy profile’ was higher in the United States compared to Canada, especially among women. Adjusted mortality hazard ratios associated with health behaviours were generally of similar magnitude and direction but often stronger in Canada. Conclusion Even when methodological and population differences are minimal, the association of health behaviours and mortality can vary across populations. It is therefore important to be cautious of between-study variation when aggregating relative effect estimates from differing populations, and when using external effect estimates for population health research and policy development

Association between Surgeon/anesthesiologist Sex Discordance and One-year Mortality Among Adults Undergoing Noncardiac Surgery

Objective: To investigate the association between surgeon-anesthesiologist sex discordance and patient mortality after noncardiac surgery. Summary Background Data: Evidence suggests different practice patterns exist amongst female and male physicians. However, the influence of physician sex on team-based practices in the operating room and subsequent patient outcomes remains unclear in the context of noncardiac surgery. Methods: We conducted a population-based, retrospective cohort study of adult Ontario residents who underwent index, inpatient noncardiac surgery between January 2007 and December 2017. Primary exposure was physician sex discordance (i.e., surgeon and anesthesiologist were of the opposite sex). The primary outcome was 1-year mortality. The association between physician sex discordance and patient outcomes was modeled using multivariable Cox proportional hazard regression with adjustment for relevant physician, patient, and hospital characteristics. Results: Of 541,209 patients, 158,084 (29.2%) were treated by sex-discordant physician teams. Physician sex discordance was associated with a lower rate of mortality at 1 year (5.2% vs. 5.7%; adjusted HR 0.95 [0.91-0.99]). Patients treated by teams composed of female surgeons and male anesthesiologists were more likely to be alive at 1 year than those treated by all-male physician teams (adjusted HR 0.90 [0.81-0.99]). Conclusions: Noncardiac surgery patients had a lower likelihood of 1-year mortality when treated by sex discordant surgeon-anesthesiologist teams. The likelihood of mortality was further reduced if the surgeon was female. Further research is needed to explore the underlying mechanisms of these observations and design strategies to diversify OR teams to optimize performance and patient outcomes