Background: Active transportation such as walking and bicycling provides an opportunity for individuals to incorporate physical activity into daily life. It has a positive impact on public health and is an important aspect of a sustainable road transport system. However, it also involves some risks. Globally, about a fifth of all fatalities within the road transport system are represented by pedestrians, and bicyclists are the road user group with the highest number of severe injuries in the European Union. Being injured in a road traffic accident may affect the individuals’ work ability and lead to sickness absence (SA) and disability pension (DP). Still, knowledge is lacking on the short- and long-term consequences of road traffic injuries among bicyclists and pedestrians in terms of SA and DP. Therefore, the aim of this thesis was to generate broader and deeper knowledge of SA and DP after a road traffic accident among injured working aged bicyclists and pedestrians.
Method: Five nationwide studies using Swedish register data of working-age individuals were conducted. Study I and Study II included all bicyclists injured in a road traffic accident in 2010. Study III and Study IV included all pedestrians injured in a road traffic accident (including fall accidents) in 2010 and 2014-2016, respectively. In Study I - Study IV SA and DP were analysed with logistic regression, sequence analysis, cluster analysis, and multinomial logistic regression. Study V included all working individuals injured in a road traffic accident (pedestrians, bicyclists, car occupants, and other road users) in 2015 and population-based matched references (matched on: sex, year of birth, level of education, country of birth, type of living area) without any traffic-related injury during 2014-2015. Mean SA and DP net days/year for each road traffic group and excess SA and DP net days/year compared with their matched references were calculated.
Results: In Study I, 85% of the 7643 injured bicyclists were injured in a single-bicycle crash. Among all, 10% were already on SA or full-time DP, while 18% started a new SA spell (>14 days) in connection with the crash. Women and older individuals had higher OR for new SA. The injury types with the highest ORs for new SA were fractures (8.04; 6.62–9.77) and internal injuries (7.34; 3.67–14.66), compared with external injuries. For the injured bicyclists in Study II, seven clusters of SA and DP were identified: “No SA or DP” (58.2% of the cohort), “Low SA or DP” (7.4%), “Immediate SA” (20.3%), “Episodic SA” (5.9%), “Long-term SA” (1.7%), “Ongoing part-time DP” (1.7%), and “Ongoing full-time DP” (4.8%). Compared to the cluster “No SA or DP”, all other clusters had higher ORs for women and older age groups. The clusters “Immediate SA” and “Episodic SA” had higher ORs for fractures, whereas the cluster “Long-term SA” had higher ORs for traumatic brain injury, not including concussion (18.4; 2.2–155.2). In Study III, 75% of the 5576 injured pedestrians were injured in a fall accident, and half of the falls were related to snow and ice. Among the injured pedestrians, 18.3% were already on SA or full-time DP, and 20% started a new SA spell in connection with the accident. Older individuals had a higher OR for new SA. Fractures were the injury type with the highest OR for new SA when compared with the reference group external injuries (9.58; 7.39-12.43). The injured body region with the highest OR for new SA, was lower leg, ankle, foot, and other leg, compared with the reference group head, face, and neck (4.52; 2.78-7.36). For the injured pedestrians in Study IV, eight clusters of SA patterns were identified. The largest cluster was characterized by no SA or DP (46.7%), four clusters had different SA patterns due to injury diagnoses (immediate (17.9%), episodic (3.9%), later (3.2%), and combined with SA due to other diagnoses (7.0%)). Two clusters had SA due to other diagnoses (short-term (16.6%) and long-term (2.0%)) and one cluster mainly consisted of individuals with DP (2.7%). Compared to the cluster “No SA”, all other clusters were associated with older age, hospitalized at inclusion, and working in health & social care. The clusters “Immediate SA”, “Episodic SA” and “Both SA due to injury and other diagnoses” were also associated with sustaining a fracture. In Study V a third of the individuals injured in a road traffic accident were bicyclists, 31% car occupants, 16% pedestrians, and 19% were other road users (mostly motorcyclists and mopeds). Pedestrians and other road users were the road user groups with the highest mean number of SA days during the first year following the accident (51 and 49 days/year respectively). The matched references had between 8 and 13 SA days/year throughout the study period. The excess SA days/year was elevated for all road user groups the whole study period. Excess SA due to injury diagnoses was 15-35 days/year during the first year following the accident. Excess SA due to diagnoses other than injuries were about eight days/year for pedestrians and car occupants during the whole study period and about zero for the bicyclists. The excess DP was low, although it increased every year for pedestrians and for car occupants; for bicyclists no excess DP was observed.
Conclusions: This thesis showed that both among injured bicyclists and pedestrians, about a fifth had new SA in connection with the accident. In addition, both groups had excess SA during the following years after the accident compared to their references. However, bicyclists’ excess SA and DP decreased faster after the accident than the pedestrians’. Fractures were associated with SA in connection with the accident for both pedestrians and bicyclists, and traumatic brain injury was associated with long-term SA for bicyclists.
