Population-attributable Fraction Of Mortality Research Articles

All-Cause and Cause-Specific Mortality Attributable to Seasonal Influenza: A Nationwide Matched Cohort Study.

Although influenza poses substantial mortality burden, most studies have estimated excess mortality using time-aggregated data. Here, we estimated mortality risk and population attributable fraction (PAF) attributed to seasonal influenza using individual-level data from a nationwide matched cohort. Individuals with influenza during four consecutive influenza seasons (2013-2017) (n = 5,497,812) and 1:4 age- and sex-matched individuals without influenza (n = 20,990,683) were identified from a national health insurance database. The endpoint was mortality within 30 days after influenza diagnosis. All-cause and cause-specific mortality risk ratios (RRs) attributed to influenza were estimated. Excess mortality, mortality RR, and PAF of mortality were determined, including for underlying disease subgroups. Excess mortality rate, mortality RR, and PAF of all-cause mortality were 49.5 per 100,000, 4.03 (95% confidence interval [CI], 3.63-4.48), and 5.6% (95% CI, 4.5-6.7%). Cause-specific mortality RR (12.85; 95% CI, 9.40-17.55) and PAF (20.7%; 95% CI, 13.2-27.0%) were highest for respiratory diseases. In subgroup analysis according to underlying disorders, PAF of all-cause mortality was 5.9% (95% CI, 0.6-10.7%) for liver disease, 5.8% (95% CI, 2.9-8.5%) for respiratory disease, and 3.8% (95% CI, 1.4-6.1%) for cancer. Individuals with influenza had a 4-fold higher mortality risk than individuals without influenza. Preventing seasonal influenza may lead to 5.6% and 20.7% reductions in all-cause and respiratory mortality, respectively. Individuals with respiratory disease, liver disease, and cancer may benefit from prioritization when establishing influenza prevention strategies.

Impact of cold spells on COPD mortality in Jiangsu Province, China.

Ambient cold is associated with substantial population attributable fraction of mortality in China, and respiratory health is vulnerable to cold exposure. This study aimed to examine the effect of cold spells on risk of deaths from chronic obstructive pulmonary disease (COPD). We collected daily data on deaths from COPD and climatic factors from 1 January 2016 to 31 December 2019 in 13 cities of Jiangsu Province, China. We used a quasi-Poisson generalized linear model coupled with a distributed lag non-linear model to quantify the association between risk of COPD deaths and exposure to cold spells (defined as 2 or more consecutive days with mean temperature ≤ 5th percentile of daily mean temperature distribution in cold months). Stratification analyses by age, sex, education, and occupation were undertaken to identify vulnerable subgroups. The results suggested that exposure to cold spells was associated with a higher risk of COPD deaths in Lianyungang (relative risk (RR): 1.70; 95% confidence interval (CI): 1.31, 2.21), Nanjing (RR: 1.54; 95% CI: 1.16, 2.04), Nantong (RR: 1.97; 95% CI: 1.68, 2.31), Suzhou (RR: 1.97; 95% CI: 1.55, 2.50), Suqian (RR: 1.68; 95% CI: 1.23, 2.29), Taizhou (RR: 1.70; 95% CI: 1.32, 2.19), Wuxi (RR: 1.99; 95% CI: 1.53, 2.60), Xuzhou (RR: 1.71; 95% CI: 1.01, 2.90), Yancheng (RR: 1.78; 95% CI: 1.53, 2.06), Yangzhou (RR: 2.78; 95% CI: 2.06, 3.76), and Zhenjiang (RR: 1.79; 95% CI: 1.26, 2.55). All subgroups seemed to be vulnerable to the effect of cold spells. The recommendation of this study is that individuals with pre-existing COPD, regardless of age, sex, education, or occupation, should be made aware of the health risk posed by cold spells and should be encouraged to take cold adaptation actions before cold season arrives. The main limitation of this study is that it is subject to ecological fallacy.

The dietary transition and its association with cardiometabolic mortality among Chinese adults, 1982–2012: a cross-sectional population-based study

Few studies have used nationally representative data to describe dietary trends and the related cardiometabolic mortality burden in China. Thus, we aimed to characterise the trends in disease-related dietary factors as well as their associated disease burden among Chinese adults from 1982 to 2012. For this cross-sectional population-based study, we analysed a nationally representative sample of 204 802 adults aged 20 years or older, using data from the 1982, 1992, 2002, and 2010-12 China National Nutrition Surveys (CNNS). We did a comparative risk assessment, in which the effects of suboptimal intakes of 12 dietary factors, individually and collectively, on cardiometabolic mortality were estimated by calculating the population attributable fraction (PAF) to estimate the proportional reduction in cardiometabolic deaths that would occur if exposure to each dietary risk factor was reduced to an alternative optimal level. The overall PAF of mortality from cardiovascular disease and type 2 diabetes that was associated with suboptimal dietary quality was 62·2% in 1982, 57·9% in 1992, 56·2% in 2002, and 51·0% in 2010-12, which accounted for 21·6% of total mortality in China in 1982, 16·6% in 1992, 17·6% in 2002, and 20·8% in 2010-12. The estimated number of cardiometabolic deaths associated with suboptimal dietary intakes was 1·07 million in 1982, 0·93 million in 1992, 1·18 million in 2002, and 1·51 million in 2010-12. Of all 12 dietary factors examined, high sodium intake (17·3%), low fruit consumption (11·5%), and low marine omega-3 fatty acids (9·7%) were associated with the largest numbers of estimated cardiometabolic deaths in 2010-12. We observed an improvement in several dietary factors in China in the past few decades. However, current intakes of these dietary factors remain suboptimal. Poor diet quality is estimated to be associated with a substantial proportion of deaths from heart disease, stroke, and type 2 diabetes in China. Ministry of Health, China, and Ministry of Science and Technology, China.

Using longitudinal syndromic surveillance to describe small ruminant health in village production systems in Myanmar

A novel syndromic surveillance approach was used to describe small ruminant health in Myanmar, to help overcome limitations in disease diagnosis common in many parts of the world, especially in low and middle income countries (LMICs). Observations were made from July 2015 to June 2016 of ten clinical syndromes in 12 goat herds and sheep flocks owned by smallholders in the Central Dry Zone. Strengths and weaknesses to using syndromic surveillance in a village setting were identified using a formal surveillance evaluation framework, ‘SERVAL’. Larger reporting teams made disproportionately more reports than smaller ones (86% compared to 14% of all reports, with a reporting rate ratio of 4.3 95% CI 3.5–5.4), which may have affected surveillance sensitivity. The benefits of the syndromic surveillance included its relatively low cost and ability to produce quantitative disease estimates that could be used to prioritise further disease investigation and extension activities. In particular, significant mortality was observed, with monthly mortality of 3.0% (95% CI 2.5–3.7%) and 0.28% (0.15–0.53%) in young and adult animals, respectively, and a population attributable fraction of mortality for young animals of 82% (68–91%). Mortality was associated with ill-thrift in young animals but had not previously been considered an important production-limiting condition in Myanmar. This information contributes to an understanding of the prevalence of excessive mortality in smallholder goat and sheep production systems. It is a practical example of the use of syndromic surveillance in a LMIC livestock production system, the results of which can direct future disease research, treatment and prevention to improve the health and productivity of small ruminants in Myanmar.

Epidemiology, Management, and Risk-Adjusted Mortality of ICU-Acquired Enterococcal Bacteremia.

Enterococcal bacteremia has been associated with high case fatality, but it remains unknown to what extent death is caused by these infections. We therefore quantified attributable mortality of intensive care unit (ICU)-acquired bacteremia caused by enterococci. From 2011 to 2013 we studied consecutive patients who stayed >48 hours in 2 tertiary ICUs in the Netherlands, using competing risk survival regression and marginal structural modeling to estimate ICU mortality caused by enterococcal bacteremia. Among 3080 admissions, 266 events of ICU-acquired bacteremia occurred in 218 (7.1%) patients, of which 76 were caused by enterococci (incidence rate, 3.0 per 1000 patient-days at risk; 95% confidence interval [CI], 2.3-3.7). A catheter-related bloodstream infection (CRBSI) was suspected in 44 (58%) of these, prompting removal of 68% of indwelling catheters and initiation of antibiotic treatment for a median duration of 3 (interquartile range 1-7) days. Enterococcal bacteremia was independently associated with an increased case fatality rate (adjusted subdistribution hazard ratio [SHR], 2.68; 95% CI, 1.44-4.98). However, for patients with CRBSI, case fatality was similar for infections caused by enterococci and coagulase-negative staphylococci (CoNS; adjusted SHR, 0.91; 95% CI, .50-1.67). Population-attributable fraction of mortality was 4.9% (95% CI, 2.9%-6.9%) by day 90, reflecting a population-attributable risk of 0.8% (95% CI, .4%-1.1%). ICU-acquired enterococcal bacteremia is associated with increased case fatality; however, the mortality attributable to these infections is low from a population perspective. The virulence of enterococci and CoNS in a setting of CRBSI seems comparable.

Abstract 2517: Deaths due to smoking in a population where women started to smoke as teenagers: Nationally representative prospective cohort study.

Abstract Background: Recent studies suggest that the population attributable fraction (PAF) of mortality due to smoking is larger than previously reported. We wanted to examine the effect of smoking on all-cause and cause-specific mortality and calculate the corresponding PAF in the Norwegian Women and Cancer Study, a nationally representative prospective cohort study. Methods: We followed 85,320 women, aged 31-70 years, who completed a questionnaire in 1991-1997, through linkages to national registries through December 2008. Questionnaire data included information on lifestyle factors, including lifetime history of smoking. Poisson regression models were fitted to estimate relative risk s (RR) with 95% confidence intervals (CIs) adjusting for age, birth cohort, education, alcohol consumption and body mass index, all at enrollment. During a mean follow-up time of 14 years 2,842 deaths occurred. Compared with that of never smokers, current smokers had a mortality rate that was double (RR=2.38; 95% CI 2.17-2.62) from deaths overall, triple (RR=3.32; 95% CI 2.27-4.85) from cerebrovascular diseases, almost four fold (RR=3.71; 95% CI 2.21-6.21) from myocardial infarction (MI), twelve times (RR=12.26; 95% CI 7.89-19.07) from lung cancer and seventeen times (RR=17.08; 95% CI 5.98-48.81) from chronic obstructive pulmonary diseases . The attributable fraction and the PAF of mortality due to smoking was 47% and 30%, respectively Conclusions: We find that one in two deaths among ever smokers, and one in three deaths among middle aged women in Norway can be attributed to smoking. Our results may be generalizable to populations where women start to smoke as teenagers. Citation Format: Inger T. Gram, Sven Sandin, Tonje Braaten, Eiliv Lund, Elisabete Weiderpass. Deaths due to smoking in a population where women started to smoke as teenagers: Nationally representative prospective cohort study. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2517. doi:10.1158/1538-7445.AM2013-2517

Population attributable fraction of mortality associated with tobacco smoking in Japan: a pooled analysis of three large-scale cohort studies.

BackgroundQuantitative measures of the burden of tobacco smoking in Asian countries are limited. We estimated the population attributable fraction (PAF) of mortality associated with smoking in Japan, using pooled data from three large-scale cohort studies.MethodsIn total, 296,836 participants (140,026 males and 156,810 females) aged 40-79 years underwent baseline surveys during the 1980s and early 1990s. The average follow-up period was 9.6 years. PAFs for all-cause mortality and individual tobacco-related diseases were estimated from smoking prevalence and relative risks.ResultsThe prevalence of current and former smokers was 54.4% and 25.1% for males, and 8.1% and 2.4% for females. The PAF of all-cause mortality was 27.8% [95% confidence interval (CI): 25.2-30.4] for males and 6.7% (95% CI: 5.9-7.5) for females. The PAF of all-cause mortality calculated by summing the disease-specific PAFs was 19.1% (95% CI: 16.0-22.2) for males and 3.6% (95% CI: 3.0-4.2) for females. The estimated number of deaths attributable to smoking in Japan in 2005 was 163,000 for males and 33,000 for females based on the former set of PAFs, and 112,000 for males and 19,000 for females based on the latter set. The leading causes of smoking-attributable deaths were cancer (61% for males and 31% for females), ischemic heart diseases and stroke (23% for males and 51% for females), and chronic obstructive pulmonary diseases and pneumonia (11% for males and 13% for females).ConclusionThe health burden due to smoking remains heavy among Japanese males. Considering the high prevalence of male current smokers and increasing prevalence of young female current smokers, effective tobacco controls and quantitative assessments of the health burden of smoking need to be continuously implemented in Japan.