Sickness absence and disability pension among injured car occupants, and associations with injury and car safety factors: A prospective cohort study.

Objective: Knowledge regarding sickness absence (SA) and disability pension (DP) following a road traffic injury, is lacking. The aim of this study was to investigate SA and DP among injured car occupants before and after a crash, accounting for permanent medical impairment (PMI). Further, to explore associations between injured body region, car model year of introduction (MYI), and European New Car Assessment Programme (Euro NCAP) safety rating and number of SA/DP days in year two and four following the crash date.

Methods: A longitudinal cohort study including 63,358 individuals injured when aged 17-62, in crashes occurring 2001-2013 and involving a car insured by the Folksam Insurance Group. Mean numbers of SA/DP net days per year were calculated, in total and by injury diagnosis category, for all, for those with SA or DP with the same diagnosis as the initial injury, and for those with and those without injuries resulting in PMI. Logistic regressions were performed to calculate odds ratios with 95% confidence intervals for having 90-180 or ≥181 combined SA/DP days, respectively, among those with injury diagnoses, in year two and four after the crash. Associations with injured body region, car model introduction year, and Euro NCAP star ratings, was investigated, with adjustments made for sociodemographics.

Results: The mean number of SA/DP days/year was higher in the years following the crash (56-50 days) compared to the year prior (41). In year one and two the increase in days was mainly with SA due to injury diagnoses and musculoskeletal diagnoses, and in year three and four, with DP due to injury diagnoses, musculoskeletal diagnoses, and mental diagnoses, respectively. Individuals whose injuries resulted in PMI had more future SA/DP days compared to those without PMI. Individuals with injuries to the torso/back and with multiple injuries were more likely to have > 180 SA/DP days both year two (2.9 and 2.2 times, respectively) and year four (2.0 and 1.6 times), compared to individuals with head injuries. Injured occupants in Euro NCAP 2-3-star rated cars as well as in untested cars, were more likely to have > 180 days in year four (1.4 and 2.0 times, respectively), compared to 4-5 stars.

Conclusion: Higher levels of SA/DP remained throughout the four years following the crash, with substantial differences between those with PMI and those with no PMI. Low overall car safety level, injuries to the torso/back, and multiple injuries were associated with high SA/DP.