Smoking and absence from work: Systematic review and meta-analysis of occupational studies

Aims: This study aimed to assess the association between smoking and absenteeism in working adults. Methods: A systematic review and meta-analysis was performed by electronic database searches in MEDLINE, EMBASE, CAB Abstracts, PubMed, Science Direct and National Health Service Economic Evaluation Database (February 2012). Longitudinal, prospective cohorts or retrospective cohorts were included in the review. Summary effect estimates were calculated using random-effects meta-analysis. Heterogeneity was assessed by I² and publication bias was investigated. Results: A total of 29 longitudinal or cohort studies were included. Compared with non-smokers, current smokers had a 33% increase in risk of absenteeism [95% confidence interval (CI): 1.25-1.41; I²=62.7%; 17 studies]. Current smokers were absent for an average of 2.74 more days per year compared with non-smokers (95% CI: 1.54-3.95; I²=89.6%; 13 studies). Compared with never smokers, ex-smokers had a 14% increase in risk of absenteeism (95% CI: 1.08-1.21; I²=62.4%; eight studies); however, no increase in duration of absence could be detected. Current smokers also had a 19% increase in risk of absenteeism compared with ex-smokers (95% CI: 1.09-1.32, P<0.01, eight studies). There was no evidence of publication bias. The total cost of absenteeism due to smoking in the United Kingdom was estimated to be £1.4 billion in 2011. Conclusions: Quitting smoking appears to reduce absenteeism and result in substantial cost-savings for employers.