Influence of occupational factors on regional differences in sick leave: A prospective population study.

Abstract

Number of sick leave days vary by county, but little is known about the extent to which this gradient may be explained by differences pertaining to occupational composition and occupational exposure. A randomly drawn cohort from the general population in Norway, aged 18-69 years, was interviewed by telephone in the second half of 2009 ( n=12,255; response at baseline=60.9%) and followed up in national registries to the end of 2010. Eligible respondents were registered with an active employee relationship in 2009 and 2010 ( n=8275). Information on counties ( n=19) was based on the administrative register. The outcome of interest was the number of physician-certified sick-leave days divided by scheduled man-days during 2010 (i.e. sick-leave percentage (SLP)). The average SLP during 2010 was 5.2%. The between-county variation in SLP ranged from 4.0% to 7.2%. Compared to the age- and gender-adjusted model, adjustment for occupation, economic sector and self-reported occupational exposure reduced the median difference in SLP between the county with the lowest SLP (reference county) and the SLP in the other counties by 1.08 percentage points (i.e. a 58% reduction). The impact of occupational composition and occupational exposure on the total between-county variance in SLP was a 16% reduction. Occupational composition and self-reported occupational exposure help to explain a significant part of the difference in SLP between counties, and appear to be more important explanatory factors than demographic variables, self-reported health and smoking.