82 research outputs found
Job strain and the risk of stroke: an individual-participant data meta-analysis
Background and Purpose—Psychosocial stress at work has been proposed to be a risk factor for cardiovascular disease. However, its role as a risk factor for stroke is uncertain.
Methods—We conducted an individual-participant-data meta-analysis of 196 380 males and females from 14 European cohort studies to investigate the association between job strain, a measure of work-related stress, and incident stroke.
Results—In 1.8 million person-years at risk (mean follow-up 9.2 years), 2023 first-time stroke events were recorded. The age- and sex-adjusted hazard ratio for job strain relative to no job strain was 1.24 (95% confidence interval, 1.05;1.47) for ischemic stroke, 1.01 (95% confidence interval, 0.75;1.36) for hemorrhagic stroke, and 1.09 (95% confidence interval, 0.94;1.26) for overall stroke. The association with ischemic stroke was robust to further adjustment for socioeconomic status.
Conclusion—Job strain may be associated with an increased risk of ischemic stroke, but further research is needed to determine whether interventions targeting job strain would reduce stroke risk beyond existing preventive strategies
Job strain as a risk factor for leisure-time physical inactivity: an individual-participant meta-analysis of up to 170,000 men and women: the IPD-Work Consortium
Unfavorable work characteristics, such as low job control and too high or too low job demands, have been suggested to increase the likelihood of physical inactivity during leisure time, but this has not been verified in large-scale studies. The authors combined individual-level data from 14 European cohort studies (baseline years from 1985–1988 to 2006–2008) to examine the association between unfavorable work characteristics and leisure-time physical inactivity in a total of 170,162 employees (50% women; mean age, 43.5 years). Of these
employees, 56,735 were reexamined after 2–9 years. In cross-sectional analyses, the odds for physical inactivity were 26% higher (odds ratio = 1.26, 95% confidence interval: 1.15, 1.38) for employees with high-strain jobs (low control/high demands) and 21% higher (odds ratio = 1.21, 95% confidence interval: 1.11, 1.31) for those with
passive jobs (low control/low demands) compared with employees in low-strain jobs (high control/low demands). In prospective analyses restricted to physically active participants, the odds of becoming physically inactive during follow-up were 21% and 20% higher for those with high-strain (odds ratio = 1.21, 95% confidence interval: 1.11, 1.32) and passive (odds ratio = 1.20, 95% confidence interval: 1.11, 1.30) jobs at baseline. These data
suggest that unfavorable work characteristics may have a spillover effect on leisure-time physical activity
Long working hours and risk of coronary heart disease and stroke: a systematic review and meta-analysis of published and unpublished data for 603 838 individuals
Background Long working hours might increase the risk of cardiovascular disease, but prospective evidence is scarce,
imprecise, and mostly limited to coronary heart disease. We aimed to assess long working hours as a risk factor for
incident coronary heart disease and stroke.
Methods We identifi ed published studies through a systematic review of PubMed and Embase from inception to
Aug 20, 2014. We obtained unpublished data for 20 cohort studies from the Individual-Participant-Data Meta-analysis
in Working Populations (IPD-Work) Consortium and open-access data archives. We used cumulative random-eff ects
meta-analysis to combine eff ect estimates from published and unpublished data.
Findings We included 25 studies from 24 cohorts in Europe, the USA, and Australia. The meta-analysis of coronary
heart disease comprised data for 603 838 men and women who were free from coronary heart disease at baseline; the
meta-analysis of stroke comprised data for 528 908 men and women who were free from stroke at baseline. Follow-up
for coronary heart disease was 5·1 million person-years (mean 8·5 years), in which 4768 events were recorded, and
for stroke was 3·8 million person-years (mean 7·2 years), in which 1722 events were recorded. In cumulative
meta-analysis adjusted for age, sex, and socioeconomic status, compared with standard hours (35–40 h per week),
working long hours (≥55 h per week) was associated with an increase in risk of incident coronary heart disease
(relative risk [RR] 1·13, 95% CI 1·02–1·26; p=0·02) and incident stroke (1·33, 1·11–1·61; p=0·002). The excess risk of
stroke remained unchanged in analyses that addressed reverse causation, multivariable adjustments for other risk
factors, and diff erent methods of stroke ascertainment (range of RR estimates 1·30–1·42). We recorded a
dose–response association for stroke, with RR estimates of 1·10 (95% CI 0·94–1·28; p=0·24) for 41–48 working
hours, 1·27 (1·03–1·56; p=0·03) for 49–54 working hours, and 1·33 (1·11–1·61; p=0·002) for 55 working hours or
more per week compared with standard working hours (ptrend<0·0001).
Interpretation Employees who work long hours have a higher risk of stroke than those working standard hours; the
association with coronary heart disease is weaker. These findings suggest that more attention should be paid to the
management of vascular risk factors in individuals who work long hours
Long working hours and change in body weight : analysis of individual-participant data from 19 cohort studies
Objective To examine the relation between long working hours and change in body mass index (BMI). Methods We performed random effects meta-analyses using individual-participant data from 19 cohort studies from Europe, US and Australia (n = 122,078), with a mean of 4.4-year follow-up. Working hours were measured at baseline and categorised as part time (= 55 h/week (long working hours). There were four outcomes at follow-up: (1) overweight/obesity (BMI >= 25 kg/m(2)) or (2) overweight (BMI 25-29.9 kg/m(2)) among participants without overweight/obesity at baseline; (3) obesity (BMI >= 30 kg/m(2)) among participants with overweight at baseline, and (4) weight loss among participants with obesity at baseline. Results Of the 61,143 participants without overweight/obesity at baseline, 20.2% had overweight/obesity at follow-up. Compared with standard weekly working hours, the age-, sex- and socioeconomic status-adjusted relative risk (RR) of overweight/obesity was 0.95 (95% CI 0.90-1.00) for part-time work, 1.07 (1.02-1.12) for 41-48 weekly working hours, 1.09 (1.03-1.16) for 49-54 h and 1.17 (1.08-1.27) for long working hours (Pfor trendPeer reviewe
Effort-Reward Imbalance at Work and Incident Coronary Heart Disease: A Multicohort Study of 90,164 Individuals.
BACKGROUND: Epidemiologic evidence for work stress as a risk factor for coronary heart disease is mostly based on a single measure of stressful work known as job strain, a combination of high demands and low job control. We examined whether a complementary stress measure that assesses an imbalance between efforts spent at work and rewards received predicted coronary heart disease. METHODS: This multicohort study (the "IPD-Work" consortium) was based on harmonized individual-level data from 11 European prospective cohort studies. Stressful work in 90,164 men and women without coronary heart disease at baseline was assessed by validated effort-reward imbalance and job strain questionnaires. We defined incident coronary heart disease as the first nonfatal myocardial infarction or coronary death. Study-specific estimates were pooled by random effects meta-analysis. RESULTS: At baseline, 31.7% of study members reported effort-reward imbalance at work and 15.9% reported job strain. During a mean follow-up of 9.8 years, 1,078 coronary events were recorded. After adjustment for potential confounders, a hazard ratio of 1.16 (95% confidence interval, 1.00-1.35) was observed for effort-reward imbalance compared with no imbalance. The hazard ratio was 1.16 (1.01-1.34) for having either effort-reward imbalance or job strain and 1.41 (1.12-1.76) for having both these stressors compared to having neither effort-reward imbalance nor job strain. CONCLUSIONS: Individuals with effort-reward imbalance at work have an increased risk of coronary heart disease, and this appears to be independent of job strain experienced. These findings support expanding focus beyond just job strain in future research on work stress
Long working hours, socioeconomic status, and the risk of incident type 2 diabetes : a meta-analysis of published and unpublished data from 222 120 individuals
Background Working long hours might have adverse health effects, but whether this is true for all socioeconomic status groups is unclear. In this meta-analysis stratified by socioeconomic status, we investigated the role of long working hours as a risk factor for type 2 diabetes. Methods We identified four published studies through a systematic literature search of PubMed and Embase up to April 30, 2014. Study inclusion criteria were English-language publication; prospective design (cohort study); investigation of the effect of working hours or overtime work; incident diabetes as an outcome; and relative risks, odds ratios, or hazard ratios (HRs) with 95% CIs, or sufficient information to calculate these estimates. Additionally, we used unpublished individual-level data from 19 cohort studies from the Individual-Participant-Data Meta-analysis in Working-Populations Consortium and international open-access data archives. Effect estimates from published and unpublished data from 222 120 men and women from the USA, Europe, Japan, and Australia were pooled with random-effects meta-analysis. Findings During 1.7 million person-years at risk, 4963 individuals developed diabetes (incidence 29 per 10 000 person-years). The minimally adjusted summary risk ratio for long (>= 55 h per week) compared with standard working hours (35-40 h) was 1.07 (95% CI 0.89-1.27, difference in incidence three cases per 10 000 person-years) with significant heterogeneity in study-specific estimates (I-2 = 53%, p = 0.0016). In an analysis stratified by socioeconomic status, the association between long working hours and diabetes was evident in the low socioeconomic status group (risk ratio 1.29, 95% CI 1.06-1.57, difference in incidence 13 per 10 000 person-years, I-2 = 0%, p = 0.4662), but was null in the high socioeconomic status group (1. 00, 95% CI 0.80-1.25, incidence diff erence zero per 10 000 person-years, I-2 = 15%, p = 0.2464). The association in the low socioeconomic status group was robust to adjustment for age, sex, obesity, and physical activity, and remained after exclusion of shift workers. Interpretation In this meta-analysis, the link between longer working hours and type 2 diabetes was apparent only in individuals in the low socioeconomic status groups. Copyright (C) Kivimaki et al. Open Access article distributed under the terms of CC BY.Peer reviewe
Work stress and risk of cancer: meta-analysis of 5700 incident cancer events in 116 000 European men and women
Peer reviewe
Comparison of alternative versions of the job demand-control scales in 17 European cohort studies : the IPD-Work consortium
BACKGROUND: Job strain (i.e., high job demands combined with low job control) is a frequently used indicator of harmful work stress, but studies have often used partial versions of the complete multi-item job demands and control scales. Understanding whether the different instruments assess the same underlying concepts has crucial implications for the interpretation of findings across studies, harmonisation of multi-cohort data for pooled analyses, and design of future studies. As part of the 'IPD-Work' (Individual-participant-data meta-analysis in working populations) consortium, we compared different versions of the demands and control scales available in 17 European cohort studies. METHODS: Six of the 17 studies had information on the complete scales and 11 on partial scales. Here, we analyse individual level data from 70 751 participants of the studies which had complete scales (5 demand items, 6 job control items). RESULTS: We found high Pearson correlation coefficients between complete scales of job demands and control relative to scales with at least three items (r > 0.90) and for partial scales with two items only (r = 0.76-0.88). In comparison with scores from the complete scales, the agreement between job strain definitions was very good when only one item was missing in either the demands or the control scale (kappa > 0.80); good for job strain assessed with three demand items and all six control items (kappa > 0.68) and moderate to good when items were missing from both scales (kappa = 0.54-0.76). The sensitivity was >0.80 when only one item was missing from either scale, decreasing when several items were missing in one or both job strain subscales. CONCLUSIONS: Partial job demand and job control scales with at least half of the items of the complete scales, and job strain indices based on one complete and one partial scale, seemed to assess the same underlying concepts as the complete survey instruments.Peer reviewe
Overweight, obesity and risk of cardiometabolic multimorbidity: pooled analysis of individual-level data for 120,813 adults from 16 cohort studies from the USA and Europe
Background Although overweight and obesity have been studied in relation to individual cardiometabolic diseases, their association with risk of cardiometabolic multimorbidity is poorly understood. Here we aimed to establish the risk of incident cardiometabolic multimorbidity (ie, at least two from: type 2 diabetes, coronary heart disease, and
stroke) in adults who are overweight and obese compared with those who are a healthy weight.
Methods We pooled individual-participant data for BMI and incident cardiometabolic multimorbidity from
16 prospective cohort studies from the USA and Europe. Participants included in the analyses were 35 years or older and had data available for BMI at baseline and for type 2 diabetes, coronary heart disease, and stroke at baseline and follow-up. We excluded participants with a diagnosis of diabetes, coronary heart disease, or stroke at or before study
baseline. According to WHO recommendations, we classified BMI into categories of healthy (20·0–24·9 kg/m²), overweight (25·0–29·9 kg/m²), class I (mild) obesity (30·0–34·9 kg/m²), and class II and III (severe) obesity (≥35·0 kg/m²). We used an inclusive definition of underweight (<20 kg/m²) to achieve sufficient case numbers for analysis. The main outcome was cardiometabolic multimorbidity (ie, developing at least two from: type 2 diabetes,
coronary heart disease, and stroke). Incident cardiometabolic multimorbidity was ascertained via resurvey or linkage to electronic medical records (including hospital admissions and death). We analysed data from each cohort separately
using logistic regression and then pooled cohort-specific estimates using random-effects meta-analysis. Findings Participants were 120 813 adults (mean age 51·4 years, range 35–103; 71445 women) who did not have diabetes, coronary heart disease, or stroke at study baseline (1973–2012). During a mean follow-up of 10·7 years (1995–2014), we
identified 1627 cases of multimorbidity. After adjustment for sociodemographic and lifestyle factors, compared with individuals with a healthy weight, the risk of developing cardiometabolic multimorbidity in overweight individuals was
twice as high (odds ratio [OR] 2·0, 95% CI 1·7–2·4; p<0·0001), almost five times higher for individuals with class I obesity (4·5, 3·5–5·8; p<0·0001), and almost 15 times higher for individuals with classes II and III obesity combined (14·5, 10·1–21·0; p<0·0001). This association was noted in men and women, young and old, and white and non-white
participants, and was not dependent on the method of exposure assessment or outcome ascertainment. In analyses of different combinations of cardiometabolic conditions, odds ratios associated with classes II and III obesity were 2·2
(95% CI 1·9–2·6) for vascular disease only (coronary heart disease or stroke), 12·0 (8·1–17·9) for vascular disease followed by diabetes, 18·6 (16·6–20·9) for diabetes only, and 29·8 (21·7–40·8) for diabetes followed by vascular disease. Interpretation The risk of cardiometabolic multimorbidity increases as BMI increases; from double in overweight people to more than ten times in severely obese people compared with individuals with a healthy BMI. Our findings highlight the need for clinicians to actively screen for diabetes in overweight and obese patients with vascular disease,
and pay increased attention to prevention of vascular disease in obese individuals with diabetes
systematic review and meta-analysis of published studies and unpublished individual participant data
Objective To quantify the association between long working hours and alcohol
use. Design Systematic review and meta-analysis of published studies and
unpublished individual participant data. Data sources A systematic search of
PubMed and Embase databases in April 2014 for published studies, supplemented
with manual searches. Unpublished individual participant data were obtained
from 27 additional studies. Review methods The search strategy was designed to
retrieve cross sectional and prospective studies of the association between
long working hours and alcohol use. Summary estimates were obtained with
random effects meta-analysis. Sources of heterogeneity were examined with
meta-regression. Results Cross sectional analysis was based on 61 studies
representing 333 693 participants from 14 countries. Prospective analysis was
based on 20 studies representing 100 602 participants from nine countries. The
pooled maximum adjusted odds ratio for the association between long working
hours and alcohol use was 1.11 (95% confidence interval 1.05 to 1.18) in the
cross sectional analysis of published and unpublished data. Odds ratio of new
onset risky alcohol use was 1.12 (1.04 to 1.20) in the analysis of prospective
published and unpublished data. In the 18 studies with individual participant
data it was possible to assess the European Union Working Time Directive,
which recommends an upper limit of 48 hours a week. Odds ratios of new onset
risky alcohol use for those working 49-54 hours and ≥55 hours a week were 1.13
(1.02 to 1.26; adjusted difference in incidence 0.8 percentage points) and
1.12 (1.01 to 1.25; adjusted difference in incidence 0.7 percentage points),
respectively, compared with working standard 35-40 hours (incidence of new
onset risky alcohol use 6.2%). There was no difference in these associations
between men and women or by age or socioeconomic groups, geographical regions,
sample type (population based v occupational cohort), prevalence of risky
alcohol use in the cohort, or sample attrition rate. Conclusions Individuals
whose working hours exceed standard recommendations are more likely to
increase their alcohol use to levels that pose a health risk
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