Ueda K, Takura T, Fujikoshi S, et al. - This study was undertaken to investigate comorbidity burden and pain-management patterns among working-aged patients with knee osteoarthritis only (KOA/O) and patients with knee osteoarthritis plus osteoarthritis at another site (KOA/+) in Japan. The Japan Medical Data Center database were applied to perform retrospective claims data analysis. Between January 1, 2011, and December 31, 2012, researchers assessed working-aged adults (aged 40 to 71 years) with 5 years of follow-up and diagnosed with knee osteoarthritis (KOA). Individuals were classified into two mutually exclusive cohorts: KOA/O and KOA/+. They further examined longitudinal pain-management patterns during each year of follow-up. The study population consisted of 2,542 patients: 1575 KOA/O and 967 KOA/+. The findings reveal that in comparison with patients with KOA/O, a greater proportion of the working population with KOA/+ received pain-related treatment. Future research is needed to investigate appropriate pain management for both KOA only and KOA with other sites.