Background

Mild traumatic brain injuries (mTBI), including concussions, following traffic accidents is common. How often these injuries lead to sickness absence (SA) among working aged individuals is however insufficiently studied. Thus, the aim of this study was to examine frequency of new SA following mTBI sustained in a road traffic environment and its associations with sociodemographic and injury-related factors.

Method

Nationwide population-based register study. Working aged individuals (18–63), living in Sweden, who in 2014 to 2016 acquired an mTBI in a traffic accident were included based on in- and specialised out-patient health care records. Information on SA (> 14 days), disability pension, pre-injury factors (age, sex, education, marital status, type of living area, country of birth, income from work) as well as injury-related factors (type of road user, in- or outpatient health care) were used in analyses of risk factors for a new SA-spell. Odds ratios (ORs), both crude and adjusted, with 95% confidence intervals (CIs) were estimated with logistic regression.

Results

6073 individuals were identified. 12% had a new SA spell after injury. Sociodemographic risk factors were female sex, older age and being born outside Sweden. Car occupants had higher ORs for new SA, compared to pedestrians, bicyclists, and other road users, and was also associated with longer duration spells (> 90 days). Having received in-patient health care was associated with an OR of 3.7 for new SA compared to those only receiving out-patient health care (including emergency department visits). Having received in-patient health care was also associated with longer duration spells.

Conclusion

A traffic related mTBI is most often a benign injury, seldom resulting in a new SA spell of longer duration. When it does, it is more likely to involve car occupants, and those who have required in-patient health care.