Sickness absence and return to work among employees with knee osteoarthritis with and without total knee arthroplasty: a prospective register linkage study among Finnish public sector employees

Objective This study aimed to examine duration of sickness absence due to knee osteoarthritis (OA) and sustained return to work (RTW) among municipal employees, who had at least one compensated sickness absence period due to knee OA. The contribution of sociodemographic characteristics, diabetes and previous sickness absence were assessed. We differentiated between participants with and without total knee arthroplasty (TKA). Methods Data from 123 506 employees in the Finnish Public Sector Study were linked with national health and mortality register information. There were 3 231 sickness absence periods (2372 participants) due to knee OA in 2005−2011. Kaplan-Meier curves for sustained RTW were obtained and median time with inter-quartile range (IQR) calculated for those with and without TKA. Cox regression analyses were carried out in multivariable analyses. Results The median time to RTW from the beginning of sickness absence was 21–28 days when TKA was not related to sickness absence and 92–145 days when it was. Among participants with no TKA, age 60−64, non-sedentary work, diabetes, and previous sickness absences predicted longer time to RTW, while pain medication predicted a shorter time. Among participants with TKA, non-sedentary work and previous sickness absences predicted a longer time to RTW. Conclusions The clinical relevance of the difference in time to RTW between employees with or without TKA was substantial. Employees with knee OA working in physically demanding jobs need work modifications after TKA, and this calls for a dialog between occupational health care professionals and workplaces.