Potential influencing factor on health-related quality of life in Japanese with knee osteoarthritis: the Locomotive syndrome and Health outcome in Aizu cohort Study (LOHAS).

PURPOSE: Several studies have investigated the factors that influence health-related quality of life in patients with knee osteoarthritis (KOA). This study aimed to identify and investigate the degree of involvement of potential factors influencing health-related quality of life (HRQOL) in an aged population with or without KOA.

METHODS: This multi-centered study included 651 participants who underwent health checkups in rural areas of Japan in 2010. The association between three component summary score of short-form 12 (physical component summary; PCS, mental component summary; MCS, and role-social component summary; RCS) and covariates were investigated using multiple linear regression model and calculated the scaled estimated regression coefficient.

RESULTS: Decreasing mobility, severity of knee pain, high pain-related self-efficacy (PSE), older age, high functional self-efficacy (FSE), and female gender had significant effect on PCS (p < 0.05). However, radiographic KOA had no influence on PCS. Presence of depression and body mass index had a significant influence on the MCS (p < 0.05). Decreasing mobility, presence of depression, PSE and older age had significant influence on the RCS (p < 0.05).

CONCLUSION: Our study results showed that physical, mental, and role/social QOL were affected by different influencing factors. Physical QOL was strongly influenced by subjective pain, physical performance, and self-efficacy, whereas radiographic KOA had no such effect. Depressive mood is associated with both mental and role/social QOL. The role/social QOL was predominantly affected by physical function and pain-related self-efficacy. Taking measure to improving functional ability and mental status might be the key factor to improve HRQOL in patient with KOA.

LEVEL OF EVIDENCE: Level 3: Epidemiologic cross-sectional study (prognostic study).