Association between obesity status and sick-leave in Swedish men: nationwide cohort study.
BACKGROUND
Sick-leave is an important source of productivity losses to society. The objective of this study was to investigate the association between body mass index (BMI) status in young adulthood and future sick-leave.


METHODS
A nation-wide cohort of 43,989 Swedish men (18.7 ± 0.5 years) performing military conscription tests in 1969-70 were followed between 1986 and 2005 regarding sick-leave. BMI was used to define underweight (<18.5), normal weight (18.5-24.9), overweight (25.0-29.9) and obesity (≥ 30.0). Relative risks of sick-leave were estimated with Cox proportional hazards models adjusted for smoking, socio-economic index and muscular strength, using normal weight as the reference.


RESULTS
During 803,684 person-years of follow-up, 488,570 sick-leave episodes were recorded. On average, one short-term (≤ 7 days) episode occurred every eight person-months, one intermediate-term (8-30 days) every five person-years and one long-term (>30 days) episode every 15 person-years. Overweight was associated with 20% and obesity with >30% risk elevation for episodes ranging from 8 to 30 days [hazard ratio (HR) 1.20; 95% CI 1.15-1.24 and HR 1.35; 95% CI 1.24-1.47, respectively] as well as for episodes >30 days (HR 1.19; 95% CI 1.15-1.23 and HR 1.34; 95% CI 1.24-1.47, respectively) compared to normal weight. Obesity was also associated with an increased risk of sick-leave episodes ≤ 7 days (HR 1.13; 95% CI 1.09-1.16), but the corresponding risk increase for overweight was very small (HR 1.02; 95% CI 1.00-1.03). Underweight showed increased risk only for short-term episodes (HR 1.05; 95% CI 1.04-1.07).


CONCLUSIONS
Overweight and obesity are associated with increased risk for sick-leave compared to normal weight, especially for sick-leave episodes of longer duration.
Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden. kristian.neovius@ki.se
Kristian
K
Neovius
Martin
M
Neovius
Malin
M
Kark
Finn
F
Rasmussen
D000293:Adolescent; D015331:Cohort Studies; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D018570:Risk Assessment; D018582:Sick Leave / Q000639:trends*; D012907:Smoking; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult