Sickness absence and disability pension among individuals injured in a bicycle crash

Abstract: Bicyclists are the road user group with the highest number of severe injuries, yet little is known about the impact of such injuries on sickness absence (SA) and disability pension (DP). Therefore, the aim was to increase the knowledge on factors associated with SA and DP among individuals of working ages, injured in a bicycle crash. Two register-based studies were conducted, including all individuals of working age and living in Sweden, who in 2010 had in- or specialized out-patient healthcare for injuries sustained in a new bicycle crash. The individuals where categorized by age, sex, crash type, type of injury, and injured body region. Study I, analyzed SA and DP at the time of the crash, the following groups were used: No new SA, Ongoing SA or full-time DP, and New SA spells >14 days. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for New SA spells >14 days, among those at risk of SA. In Study II, weekly SA/DP data for one year before and through three years after the crash date were used in sequence and cluster analyses. Multinomial logistic regression was used to estimate OR and 95% CI for factors associated with each sequence cluster. In Study I, a total of 7643 individuals aged 16-64 years, had specialized healthcare due to a new bicycle crash in 2010, of which the majority (85%) were single-bicycle crashes. Among all, 10% were already on SA or full-time DP at the time of the crash, while 18% had a new SA spell. The most common types of injuries were external injuries (38%) and fractures (37%). The body region most frequently injured was the upper extremities (43%). The OR for New SA was higher for women compared to men (OR 1.40; 95% CI 1.23-1.58) and for higher ages compared to younger (OR 2.50; 2.02-3.09, for ages: 55-64 vs. 25-34). Fractures and internal injuries were the type of injury with the highest OR for New SA compared with external injuries (8.04; 6.62-9.77 and 7.34; 3.67-14.66, respectively). The body regions with the highest ORs for New SA, compared with injuries to the ‘head, face, and neck, not traumatic brain injury’ were injuries to the ‘spine and back’ (3.53; 2.24-5.55) and ‘traumatic brain injury, not concussion’ (2.72; 1.19-6.22). In Study II, including 6353 individuals aged 18-59 years, injured in a bicycle crash 2010, and alive and living in Sweden during the whole follow-up, seven clusters were identified and named: "No SA or DP" (58.2% of all), "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 reference cluster, "No SA or DP", all other clusters were associated with a higher proportion of women, individuals of older age, and individuals who had only high school education (compared to university/college). Further, inpatient healthcare had high OR for all clusters but "Low SA or DP" compared with the cluster “No SA or DP”. There were three clusters with different levels of SA. The clusters "Immediate SA" and "Episodic SA" had higher OR for fractures and injuries to the ‘spine and back’, the clusters "Episodic SA" and “Long-term SA” had higher OR for ‘traumatic brain injury, not concussion’, and the cluster “Long-term SA” had also higher OR for collisions with motor vehicles compared with the cluster “No SA or DP”. Bicycling is an important part of a sustainable transportation system, but is not risk-free. Among individuals of working age who in 2010 had incident in- or specialized out-patient healthcare for injuries sustained in a bicycle crash, 18% had a new SA spell in connection to the crash. Seven clusters of SA and DP sequences were identified displaying that sequence analysis enabled exploration of different characteristics across different patterns of SA and DP following a bicycle crash.