Worked to death? A census-based longitudinal study of the relationship between the numbers of hours spent working and mortality risk.
BACKGROUND
There has been an increasing interest in the health effects of long working hours, but little empirical evidence to substantiate early case series suggesting an increased mortality risk. The aim of the current study is to quantify the mortality risk associated with long working hours and to see if this varies by employment relations and conditions of occupation.


METHODS
A census-based longitudinal study of 414 949 people aged 20-59/64 years, working at least 35 h/week, subdivided into four occupational classes (managerial/professional, intermediate, own account workers, workers in routine occupations) with linkage to deaths records over the following 8.7 years. Cox proportional hazards models were used to examine all-cause and cause-specific mortality risk.


RESULTS
Overall 9.4% of the cohort worked 55 or more h/week, but this proportion was greater in the senior management and professional occupations and in those who were self-employed. Analysis of 4447 male and 1143 female deaths showed that hours worked were associated with an increased risk of all-cause mortality only for men working for more than 55 or more h/week in routine/semi-routine occupations [adjusted hazard ratios (adjHR) 1.31: 95% confidence interval (CI) 1.11, 1.55] compared with their peers working 35-40 h/week. Their equivalent risk of death from cardiovascular disease was (adjHR 1.49: 95% CI 1.10, 2.00).


CONCLUSIONS
These findings substantiate and add to the earlier studies indicating the deleterious impact of long working hours but also suggest that the effects are moderated by employment relations or conditions of occupation. The policy implications of these findings are discussed.
["O'Reilly|Dermot|D|", 'Rosato|Michael|M|']
D000059:Accidents D000328:Adult D002318:Cardiovascular Diseases D002423:Cause of Death D019352:Censuses D004651:Employment D005260:Female D006801:Humans D008137:Longitudinal Studies D008297:Male D008875:Middle Aged D009026:Mortality D009660:Northern Ireland D016016:Proportional Hazards Models D012307:Risk Factors D016526:Workload D055815:Young Adult
longitudinal study mortality Hours worked