Long-term ambient air pollution exposure and cardio-respiratory disease in China: findings from a prospective cohort study.

BACKGROUND: Existing evidence on long-term ambient air pollution (AAP) exposure and risk of cardio-respiratory diseases in China is mainly on mortality, and based on area average concentrations from fixed-site monitors for individual exposures. Substantial uncertainty persists, therefore, about the shape and strength of the relationship when assessed using more personalised individual exposure data. We aimed to examine the relationships between AAP exposure and risk of cardio-respiratory diseases using predicted local levels of AAP. METHODS: A prospective study included 50,407 participants aged 30-79 years from Suzhou, China, with concentrations of nitrogen dioxide (NO2), sulphur dioxide (SO2), fine (PM2.5), and inhalable (PM10) particulate matter, ozone (O3) and carbon monoxide (CO) and incident cases of cardiovascular disease (CVD) (n = 2,563) and respiratory disease (n = 1,764) recorded during 2013-2015. Cox regression models with time-dependent covariates were used to estimate adjusted hazard ratios (HRs) for diseases associated with local-level concentrations of AAP exposure, estimated using Bayesian spatio-temporal modelling. RESULTS: The study period of 2013-2015 included a total of 135,199 person-years of follow-up for CVD. There was a positive association of AAP, particularly SO2 and O3, with risk of major cardiovascular and respiratory diseases. Each 10 µg/m3 increase in SO2 was associated with adjusted hazard ratios (HRs) of 1.07 (95% CI: 1.02, 1.12) for CVD, 1.25 (1.08, 1.44) for COPD and 1.12 (1.02, 1.23) for pneumonia. Similarly, each 10 µg/m3 increase in O3 was associated with adjusted HR of 1.02 (1.01, 1.03) for CVD, 1.03 (1.02, 1.05) for all stroke, and 1.04 (1.02, 1.06) for pneumonia. CONCLUSIONS: Among adults in urban China, long-term exposure to ambient air pollution is associated with a higher risk of cardio-respiratory disease.

Occupational inhalant exposures and longitudinal lung function decline.

BACKGROUND: Airborne exposures at the workplace are believed to be associated with lung function decline. However, longitudinal studies are few, and results are conflicting. METHODS: Participants from two general population-based cohorts, the Copenhagen City Heart Study and the Copenhagen General Population Study, with at least two lung function measurements were followed for a mean of 9 years (range 3-27 years). Occupational exposure was assigned to each year of follow-up between the two lung function measurements by a job exposure matrix. Associations between mean occupational exposure per year and mean annual decline in forced expiratory volume in 1 s (FEV1) were investigated using linear mixed-effects models according to cohort and time period (1976-1983 and 2003-2015). We adjusted for sex, height, weight, education, baseline FEV1 and pack-years of smoking per year during follow-up. RESULTS: A total of 16 144 individuals were included (mean age 48 years and 43% male). Occupational exposure to mineral dusts, biological dusts, gases and fumes and a composite category was not associated with FEV1 decline in analyses with dichotomised exposure. In analyses with an indexed measure of exposure, gases and fumes were associated with an FEV1 change of -5.8 mL per unit per year (95% CI -10.8- -0.7 mL per unit per year) during 1976-1983, but not during 2001-2015. CONCLUSION: In two cohorts from the Danish general population, occupational exposure to dusts, gases and fumes was not associated with excess lung function decline in recent years but might have been of importance decades ago.

Impact of deprivation, dementia prevalence and regional demography on prescribing of antidementia drugs in England: A time trend analysis.

AIM: This study aimed to examine trends in prescribing of antidementia drugs in primary care in England between 2009 and 2019, and investigate the impact of deprivation, regional demography and disease prevalence on prescribing practices. METHODS: Analysis of publicly available government data from various sources pertaining to primary care prescribing and demographics was conducted. All primary care prescription data pertaining to antidementia drugs in England between 2009 and 2019 were extracted and adjusted for inflation and population changes. Data across English clinical commissioning regions were compared to explore the association between prescribing trend, deprivation, regional demography and dementia prevalence. RESULTS: The number of prescription items for antidementia drugs in England increased by approximately 3-fold (195.4%) from 24 items/1000 population in 2009 to 70.9 items/1000 population in 2019. In 2019, the least-deprived areas had approximately twice the rate of prescribing of antidementia drugs compared to the most-deprived areas (median [IQR] values of 46.7 [36.6-64.8] vs 91.23 [76.2-95.1] items/1000 population, respectively). In the multivariable analysis, the number of prescription items showed an inverse relationship with deprivation (coefficient -0.046, 95% CI -0.47 to -0.045) after adjustment for number of populations aged 65+ years and prevalence of dementia. CONCLUSIONS: The 3-fold rise in the number of prescription items for antidementia drugs in the study period reflects the policy emphasis on early diagnosis and treatment of dementia. Higher rates of prescribing in the least-deprived areas may be reflective of better and early diagnoses and access to treatments. Such inequality in access to the treatments needs to be investigated further.

Chronic productive cough and inhalant occupational exposure-a study of the general population.

PURPOSE: Occupational inhalant exposures have been linked with a higher occurrence of chronic productive cough, but recent studies question the association. METHODS: We included participants from two general population studies, the Copenhagen City General Population Study and the Copenhagen City Heart Study, to assess contemporary (year 2003-2017) and historical (1976-1983) occupational inhalant hazards. Job titles one year prior to study inclusion and an airborne chemical job-exposure matrix (ACE JEM) were used to estimate occupational exposure. The association between occupational exposures and self-reported chronic productive cough was studied using generalized estimating equations stratified by smoking status and cohort. RESULTS: The population consisted of 5210 working individuals aged 20-65 from 1976 to 1983 and 64,279 from 2003 to 2017. In smokers, exposure to high levels of mineral dust, biological dust, gases & fumes and the composite variable vapours, gases, dusts or fumes (VGDF) were associated with chronic productive cough in both cohorts with odds ratios in the range of 1.2 (95% confidence interval, 1.0;1.4) to 1.6 (1.2;2.1). High levels of biological dust were only associated with an increased risk of a chronic productive cough in the 2003-2017 cohort (OR 1.5 (1.1;2.0)). In non-smokers, high levels of VGDF (OR 1.5 (1.0;2.3)) and low levels of mineral dust (OR 1.7 (1.1;2.4)) were associated with chronic productive cough in the 1976-1983 cohort, while no associations were seen in non-smokers in the 2003-2017 cohort. CONCLUSION: Occupational inhalant exposure remains associated with a modestly increased risk of a chronic productive cough in smokers, despite declining exposure levels during the past four decades.

Prevalence of Stroke and Stroke Risk Factors in a South-Western Community of Nepal.

BACKGROUND: Stroke related studies in Nepal are primarily hospital-based and mainly from the capital city. OBJECTIVES: We aimed to estimate the prevalence of stroke and stroke risk factors in the South-Western community of Nepal. METHODS: A cross-sectional study was conducted from May to August 2018 among 549 randomly selected Nepalese participants from diverse ethnicity, aged ≥15 years, in a region with the availability of neurological support facilities. Data were collected using a stroke questionnaire designed for the purpose. Stroke was identified by enumerators using the Balance-Eyes-Face-Arms-Speech-Time (BEFAST) scale, and a senior neurologist confirmed it. We assessed the presence of major risk factors associated with stroke. RESULTS: The crude and age-standardised prevalence of stroke were 2368 and 2967 per 100,000 respectively. Of all the surveyed participants, 61% (n=335) reported consumption of full-fat dairy products >3 days per week, 87.6% (n=481) reported a high intake of salt (>5 g/day), 83.6% (n=459) with a low intake of fruits and vegetables (<400 g/day), 45.2% (n=248) with perceived stress related to work or home, 51.6% (n=283) with financial stress (283, 51.6%), 86.7% (n=457) with low high-density lipoprotein, 96.2% (n=507) with high blood urea nitrogen, 47.1% (n=356) were either overweight or obese 20.4% (n=112) with hypertension and 6.2% (n=34) with diabetes. CONCLUSIONS: The prevalence of stroke in the community of the South-Western part of Nepal is relatively higher than that estimated in South-Asia and global context. Our findings suggest an urgent community intervention, particularly with healthy lifestyles changes for future stroke prevention in the high-risk group.

The burden of chronic respiratory diseases in adults in Nepal: A systematic review.

While chronic lung disease causes substantial global morbidity and mortality, global estimates have primarily been based on broad assumptions. Specific country data from low-income countries such as Nepal are limited. This review assessed primary evidence on chronic respiratory disease burden among adults in Nepal. A systematic search was performed in June 2019 (updated May 2020) for studies through nine databases. High levels of heterogeneity deemed a narrative synthesis appropriate. Among 27 eligible studies identified, most were low-moderate quality with cross-sectional and retrospective study design. Chronic lung diseases identified were chronic obstructive pulmonary disease (COPD), asthma, bronchiectasis and restrictive lung diseases. Studies were categorised as: (i) community-based, (ii) hospital-based and (iii) comorbidity-related and disease burden. Reported disease prevalence varied widely (COPD, 1.67-14.3%; asthma, 4.2-8.9%). The prevalence of airflow obstruction was higher among rural dwellers (15.8%) and those exposed to household air pollution from domestic biomass burning as opposed to liquid petroleum gas users (Odds Ratio: 2.06). Several comorbidities, including hypertension and diabetes mellitus added to the disease burden. The review shows limited literature on lung disease burden in Nepal. Publications varied in terms of overall quality. Good quality research studies with prospective cohorts related to respiratory conditions are required.

Occupational exposure to inhaled pollutants and risk of airflow obstruction: a large UK population-based UK Biobank cohort.

BACKGROUND: Although around 10% to 15% of COPD burden can be attributed to workplace exposures, little is known about the role of different airborne occupational pollutants (AOP). The main aim of the study was to assess the effect size of the relationship between various AOP, their level and duration of exposure with airflow obstruction (AFO). METHODS: A cross-sectional analysis was conducted in 228 614 participants from the UK Biobank study who were assigned occupational exposure using a job exposure matrix blinded to health outcome. Adjusted prevalence ratios (PRs) and 95% CI for the risk of AFO for ever and years of exposure to AOPs were estimated using robust Poisson model. Sensitivity analyses were conducted for never-smokers, non-asthmatic and bi-pollutant model. RESULTS: Of 228 614 participants, 77 027 (33.7%) were exposed to at least one AOP form. 35.5% of the AFO cases were exposed to vapours, gases, dusts or fumes (VGDF) and 28.3% to dusts. High exposure to vapours increased the risk of occupational AFO by 26%. Exposure to dusts (adjusted PR=1.05; 95% CI 1.01 to 1.08), biological dusts (1.05; 1.01 to 1.10) and VGDF (1.04; 1.01 to 1.07) showed a significantly increased risk of AFO, however, statistically not significant following multiple testing. There was no significant increase in risk of AFO by duration (years) of exposure in current job. The results were null when restricted to never-smokers and when a bi-pollutant model was used. However, when data was analysed based on the level of exposure (low, medium and high) compared with no exposure, directionally there was increase in risk for those with high exposure to vapours, gases, fumes, mists and VGDF but statistically significant only for vapours. CONCLUSION: High exposure (in current job) to airborne occupational pollutants was suggestive of higher risk of AFO. Future studies should investigate the relationship between lifetime occupational exposures and COPD.

Solid Fuel Use and Risks of Respiratory Diseases. A Cohort Study of 280,000 Chinese Never-Smokers.

RATIONALE: Little evidence from large-scale cohort studies exists about the relationship of solid fuel use with hospitalization and mortality from major respiratory diseases. OBJECTIVES: To examine the associations of solid fuel use and risks of acute and chronic respiratory diseases. METHODS: A cohort study of 277,838 Chinese never-smokers with no prior major chronic diseases at baseline. During 9 years of follow-up, 19,823 first hospitalization episodes or deaths from major respiratory diseases, including 10,553 chronic lower respiratory disease (CLRD), 4,398 chronic obstructive pulmonary disease (COPD), and 7,324 acute lower respiratory infection (ALRI), were recorded. Cox regression yielded adjusted hazard ratios (HRs) for disease risks associated with self-reported primary cooking fuel use. MEASUREMENTS AND MAIN RESULTS: Overall, 91% of participants reported regular cooking, with 52% using solid fuels. Compared with clean fuel users, solid fuel users had an adjusted HR of 1.36 (95% confidence interval, 1.32-1.40) for major respiratory diseases, whereas those who switched from solid to clean fuels had a weaker HR (1.14, 1.10-1.17). The HRs were higher in wood (1.37, 1.33-1.41) than coal users (1.22, 1.15-1.29) and in those with prolonged use (≥40 yr, 1.54, 1.48-1.60; <20 yr, 1.32, 1.26-1.39), but lower among those who used ventilated than nonventilated cookstoves (1.22, 1.19-1.25 vs. 1.29, 1.24-1.35). For CLRD, COPD, and ALRI, the HRs associated with solid fuel use were 1.47 (1.41-1.52), 1.10 (1.03-1.18), and 1.16 (1.09-1.23), respectively. CONCLUSIONS: Among Chinese adults, solid fuel use for cooking was associated with higher risks of major respiratory disease admissions and death, and switching to clean fuels or use of ventilated cookstoves had lower risk than not switching.

ERS/ATS workshop report on respiratory health effects of household air pollution.

Exposure to household air pollution (HAP) from solid fuel combustion affects almost half of the world population. Adverse respiratory outcomes such as respiratory infections, impaired lung growth and chronic obstructive pulmonary disease have been linked to HAP exposure. Solid fuel smoke is a heterogeneous mixture of various gases and particulates. Cell culture and animal studies with controlled exposure conditions and genetic homogeneity provide important insights into HAP mechanisms. Impaired bacterial phagocytosis in exposed human alveolar macrophages possibly mediates several HAP-related health effects. Lung pathological findings in HAP-exposed individuals demonstrate greater small airways fibrosis and less emphysema compared with cigarette smokers. Field studies using questionnaires, air pollution monitoring and/or biomarkers are needed to better establish human risks. Some, but not all, studies suggest that improving cookstove efficiency or venting emissions may be associated with reduced respiratory symptoms, lung function decline in women and severe pneumonia in children. Current studies focus on fuel switching, stove technology replacements or upgrades and air filter devices. Several governments have initiated major programmes to accelerate the upgrade from solid fuels to clean fuels, particularly liquid petroleum gas, which provides research opportunities for the respiratory health community.

Cardiorespiratory health effects of gaseous ambient air pollution exposure in low and middle income countries: a systematic review and meta-analysis.

BACKGROUND: Lack of research on the effects of gaseous pollutants (nitrogen oxides [NOx], sulfur dioxide [SO2], carbon monoxide [CO] and ozone [O3]) in the ambient environment on health outcomes from within low and middle income countries (LMICs) is leading to reliance on results from studies performed within high income countries (HICs). This systematic review and meta-analysis examines the cardiorespiratory health effects of gaseous pollutants in LMICs exclusively. METHODS: Systematic searching was carried out and estimates pooled by pollutant, lag and outcome, and presented as excess relative risk per 10 µg/m3 (NOx, SO2, O3) or 1 ppm (CO) increase pollutant. Sub-group analysis was performed examining estimates by specific outcomes, city and co-pollutant adjustment. RESULTS: Sixty studies met the inclusion criteria, most (44) from the East Asia and Pacific region. A 10 µg/m3 increase in same day NOx was associated with 0.92% (95% CI: 0.44, 1.39), and 0.70% (0.01, 1.40) increases in cardiovascular and respiratory mortality respectively, same day NOx was not associated with morbidity. Same day sulfur dioxide was associated with 0.73% (0.04, 1.42) and 0.50% (0.01, 1.00) increases in respiratory morbidity and in cardiovascular mortality respectively. CONCLUSIONS: Acute exposure to gaseous ambient air pollution (AAP) is associated with increases in morbidity and mortality in LMICs, with greatest associations observed for cardiorespiratory mortality.

Association of Solid Fuel Use With Risk of Cardiovascular and All-Cause Mortality in Rural China.

Importance: When combusted indoors, solid fuels generate a large amount of pollutants such as fine particulate matter. Objective: To assess the associations of solid fuel use for cooking and heating with cardiovascular and all-cause mortality. Design, Setting, and Participants: This nationwide prospective cohort study recruited participants from 5 rural areas across China between June 2004 and July 2008; mortality follow-up was until January 1, 2014. A total of 271 217 adults without a self-reported history of physician-diagnosed cardiovascular disease at baseline were included, with a random subset (n = 10 892) participating in a resurvey after a mean interval of 2.7 years. Exposures: Self-reported primary cooking and heating fuels (solid: coal, wood, or charcoal; clean: gas, electricity, or central heating), switching of fuel type before baseline, and use of ventilated cookstoves. Main Outcomes and Measures: Death from cardiovascular and all causes, collected through established death registries. Results: Among the 271 217 participants, the mean (SD) age was 51.0 (10.2) years, and 59% (n = 158 914) were women. A total of 66% (n = 179 952) of the participants reported regular cooking (at least weekly) and 60% (n = 163 882) reported winter heating, of whom 84% (n = 150 992) and 90% (n = 147 272) used solid fuels, respectively. There were 15 468 deaths, including 5519 from cardiovascular causes, documented during a mean (SD) of 7.2 (1.4) years of follow-up. Use of solid fuels for cooking was associated with greater risk of cardiovascular mortality (absolute rate difference [ARD] per 100 000 person-years, 135 [95% CI, 77-193]; hazard ratio [HR], 1.20 [95% CI, 1.02-1.41]) and all-cause mortality (ARD, 338 [95% CI, 249-427]; HR, 1.11 [95% CI, 1.03-1.20]). Use of solid fuels for heating was also associated with greater risk of cardiovascular mortality (ARD, 175 [95% CI, 118-231]; HR, 1.29 [95% CI, 1.06-1.55]) and all-cause mortality (ARD, 392 [95% CI, 297-487]; HR, 1.14 [95% CI, 1.03-1.26]). Compared with persistent solid fuel users, participants who reported having previously switched from solid to clean fuels for cooking had a lower risk of cardiovascular mortality (ARD, 138 [95% CI, 71-205]; HR, 0.83 [95% CI, 0.69-0.99]) and all-cause mortality (ARD, 407 [95% CI, 317-497]; HR, 0.87 [95% CI, 0.79-0.95]), while for heating, the ARDs were 193 (95% CI, 128-258) and 492 (95% CI, 383-601), and the HRs were 0.57 (95% CI, 0.42-0.77) and 0.67 (95% CI, 0.57-0.79), respectively. Among solid fuel users, use of ventilated cookstoves was also associated with lower risk of cardiovascular mortality (ARD, 33 [95% CI, -9 to 75]; HR, 0.89 [95% CI, 0.80-0.99]) and all-cause mortality (ARD, 87 [95% CI, 20-153]; HR, 0.91 [95% CI, 0.85-0.96]). Conclusions and Relevance: In rural China, solid fuel use for cooking and heating was associated with higher risks of cardiovascular and all-cause mortality. These risks may be lower among those who had previously switched to clean fuels and those who used ventilation.

Informed Consent in Health Research: Challenges and Barriers in Low-and Middle-Income Countries with Specific Reference to Nepal.

Obtaining 'informed consent' from every individual participant involved in health research is a mandatory ethical practice. Informed consent is a process whereby potential participants are genuinely informed about their role, risk and rights before they are enrolled in the study. Thus, ethics committees in most countries require 'informed consent form' as part of an ethics application which is reviewed before granting research ethics approval. Despite a significant increase in health research activity in low-and middle-income countries (LMICs) in recent years, only limited work has been done to address ethical concerns. Most ethics committees in LMICs lack the authority and/or the capacity to monitor research in the field. This is important since not all research, particularly in LMICs region, complies with ethical principles, sometimes this is inadvertently or due to a lack of awareness of their importance in assuring proper research governance. With several examples from Nepal, this paper reflects on the steps required to obtain informed consents and highlights some of the major challenges and barriers to seeking informed consent from research participants. At the end of this paper, we also offer some recommendations around how can we can promote and implement optimal informed consent taking process. We believe that paper is useful for researchers and members of ethical review boards in highlighting key issues around informed consent.

Prevalence and correlates of airflow obstruction in ∼317,000 never-smokers in China.

In China, the burden of chronic obstructive disease (COPD) is high in never-smokers but little is known about its causes in this group. We analysed data on 287 000 female and 30 000 male never-smokers aged 30-79 years from 10 regions in China, who participated in the China Kadoorie Biobank baseline survey (2004-2008). Prevalence of airflow obstruction (AFO) (pre-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.7 and below the lower limit of normal (LLN)) was estimated, by age and region. Cross-sectional associations of AFO (FEV1/FVC <0.7), adjusted for confounding, were examined. AFO prevalence defined as FEV1/FVC <0.7 was 4.0% in females and 5.1% in males (mean ages 51 and 54 years, respectively). AFO prevalence defined as FEV1/FVC

The effect of exposure to biomass smoke on respiratory symptoms in adult rural and urban Nepalese populations.

BACKGROUND: Half of the world's population is exposed to household air pollution from biomass burning. This study aimed to assess the relationship between respiratory symptoms and biomass smoke exposure in rural and urban Nepal. METHODS: A cross-sectional study of adults (16+ years) in a rural population (n = 846) exposed to biomass smoke and a non-exposed urban population (n = 802) in Nepal. A validated questionnaire was used along with measures of indoor air quality (PM2.5 and CO) and outdoor PM2.5. RESULTS: Both men and women exposed to biomass smoke reported more respiratory symptoms compared to those exposed to clean fuel. Women exposed to biomass were more likely to complain of ever wheeze (32.0 % vs. 23.5%; p = 0.004) and breathlessness (17.8% vs. 12.0%, p = 0.017) compared to males with tobacco smoking being a major risk factor. Chronic cough was similar in both the biomass and non-biomass smoke exposed groups whereas chronic phlegm was reported less frequently by participants exposed to biomass smoke. Higher PM2.5 levels (≥2 SDs of the 24-hour mean) were associated with breathlessness (OR = 2.10, 95% CI 1.47, 2.99) and wheeze (1.76, 1.37, 2.26). CONCLUSIONS: The study suggests that while those exposed to biomass smoke had higher prevalence of respiratory symptoms, urban dwellers (who were exposed to higher ambient air pollution) were more at risk of having productive cough.

Association between PM10 exposure and risk of myocardial infarction in adults: A systematic review and meta-analysis.

BACKGROUND: Air pollution has several negative health effects. Particulate matter (PM) is a pollutant that is often linked to health adversities. PM2.5 (PM with an aerodynamic diameter of ≤2.5µm) exposure has been associated with negative cardiovascular (CV) outcomes. However, the impact of PM10 (PM with an aerodynamic diameter of ≤10µm) exposure is often overlooked due to its limited ability to pass the alveolar barrier. This study aims to assess the association between PM10 exposure and risk of myocardial infarction (MI) amongst adults (≥18 years of age) as this has been poorly studied. METHODS: The study protocol was published on the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023409796) on March 31, 2023. Literature searches were conducted on 4 databases (Ovid Medline, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Web of Science) on January 17, 2023, for studies looking at associations between PM and MI. English studies from all time periods were assessed. Studies selected for review were time-series, case-crossover, and cohort studies which investigated the risk of MI as an outcome upon PM10 exposure. The quality of evidence was assessed using Cochrane's Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Data for different risk outcomes (risk ratio (RR), odds ratio (OR), hazard ratio (HR)) and 3 lags was meta-analyzed using an inverse variance statistical analysis using a random effects model. The pooled effect sizes and the 95% confidence intervals (CIs) were reported in forest plots. RESULTS: Among the 1,099 studies identified, 41 were included for review and 23 were deemed eligible for meta-analysis. Our analysis revealed that there is an increased risk (OR = 1.01; 95% CI:1.00-1.02) of MI with a 10 µg/m3 increase in PM10 after a lag 0 and lag 1 delay. CONCLUSIONS: Our findings indicate that PM10 exposure is associated with an increased risk of MI. This can aid in informing environmental policy-making, personal-level preventative measures, and global public health action.

Effects of ambient air pollution on obesity and ectopic fat deposition: a protocol for a systematic review and meta-analysis.

INTRODUCTION: Globally, the prevalence of obesity tripled from 1975 to 2016. There is evidence that air pollution may contribute to the obesity epidemic through an increase in oxidative stress and inflammation of adipose tissue. However, the impact of air pollution on body weight at a population level remains inconclusive. This systematic review and meta-analysis will estimate the association of ambient air pollution with obesity, distribution of ectopic adipose tissue, and the incidence and prevalence of non-alcoholic fatty liver disease among adults. METHODS AND ANALYSIS: The study will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for conduct and reporting. The search will include the following databases: Ovid Medline, Embase, PubMed, Web of Science and Latin America and the Caribbean Literature on Health Sciences, and will be supplemented by a grey literature search. Each article will be independently screened by two reviewers, and relevant data will be extracted independently and in duplicate. Study-specific estimates of associations and their 95% Confidence Intervals will be pooled using a DerSimonian and Laird random-effects model, implemented using the RevMan software. The I2 statistic will be used to assess interstudy heterogeneity. The confidence in the body of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. ETHICS AND DISSEMINATION: As per institutional policy, ethical approval is not required for secondary data analysis. In addition to being published in a peer-reviewed journal and presented at conferences, the results of the meta-analysis will be shared with key stakeholders, health policymakers and healthcare professionals. PROSPERO REGISTRATION NUMBER: CRD42023423955.

Health trends in Canada 1990-2019: An analysis for the Global Burden of Disease Study.

OBJECTIVE: Monitoring trends in key population health indicators is important for informing health policies. The aim of this study was to examine population health trends in Canada over the past 30 years in relation to other countries. METHODS: We used data on disability-adjusted life years (DALYs), years of life lost (YLL), years lived with disability, life expectancy (LE), and child mortality for Canada and other countries between 1990 and 2019 provided by the Global Burden of Disease Study. RESULTS: Life expectancy, age-standardized YLL, and age-standardized DALYs all improved in Canada between 1990 and 2019, although the rate of improvement has leveled off since 2011. The top five causes of all-age DALYs in Canada in 2019 were neoplasms, cardiovascular diseases, musculoskeletal disorders, neurological disorders, and mental disorders. The greatest increases in all-age DALYs since 1990 were observed for substance use, diabetes and chronic kidney disease, and sense organ disorders. Age-standardized DALYs declined for most conditions, except for substance use, diabetes and chronic kidney disease, and musculoskeletal disorders, which increased by 94.6%, 14.6%, and 7.3% respectively since 1990. Canada's world ranking for age-standardized DALYs declined from 9th place in 1990 to 24th in 2019. CONCLUSION: Canadians are healthier today than in 1990, but progress has slowed in Canada in recent years in comparison with other high-income countries. The growing burden of substance abuse, diabetes/chronic kidney disease, and musculoskeletal diseases will require continued action to improve population health.

RéSUMé: OBJECTIF: La surveillance des tendances des indicateurs clés de la santé de la population est importante pour éclairer les politiques de santé. Dans cette étude, nous avons examiné les tendances de la santé de la population au Canada au cours des 30 dernières années par rapport à d'autres pays. MéTHODES: Nous avons utilisé des données sur les années de vie ajustées en fonction de l'incapacité (DALY), les années de vie perdues (YLL), les années vécues avec un handicap, l'espérance de vie (LE) et la mortalité infantile pour le Canada et d'autres pays entre 1990 et 2019, fournies par l'Étude mondiale sur le fardeau de la maladie. RéSULTATS: L'espérance de vie, les YLL ajustées selon l'âge et les DALY ajustées selon l'âge ont tous connu une amélioration au Canada entre 1990 et 2019, bien que le taux d'amélioration se soit stabilisé depuis 2011. Les cinq principales causes des DALY pour tous les âges au Canada en 2019 étaient les néoplasmes, les maladies cardiovasculaires, les affections musculosquelettiques, les affections neurologiques et les troubles mentaux. Les plus fortes augmentations des DALY pour tous les âges depuis 1990 ont été observées pour l'usage de substances, le diabète et les maladies rénales chroniques, ainsi que les troubles des organes sensoriels. Les DALY ajustées selon l'âge ont diminué pour la plupart des conditions, à l'exception de l'usage de substances, du diabète et des maladies rénales chroniques, ainsi que des troubles musculosquelettiques, qui ont augmenté de 94,6 %, 14,6 % et 7,3 % respectivement depuis 1990. Le classement mondial du Canada pour les DALY ajustées selon l'âge est diminué de la 9ième place en 1990 à la 24ième place en 2019. CONCLUSION: Les Canadiens sont en meilleure santé aujourd'hui qu'en 1990, mais les progrès se sont ralentis ces dernières années par rapport à d'autres pays à revenu élevé. La croissance du fardeau lié à l'abus de substances, au diabète/maladies rénales chroniques et aux affections musculosquelettiques exigera des actions continues pour améliorer la santé de la population.