Association Between Knee Pain, Impaired Function, and Development of Depressive Symptoms.

OBJECTIVES: To examine the association between knee pain and function and depressive symptoms in older Japanese adults.

DESIGN: Community-based prospective cohort study.

SETTING: Kurabuchi Town, Gumma Prefecture, Japan.

PARTICIPANTS: Individuals aged 65 and older (N = 573; n = 260 men, n = 313 women) without depressive symptoms participated in baseline examinations in 2005 and 2006; 95.6% participated in follow-up interviews (2007-08).

MEASUREMENTS: Degree of knee pain and functional impairment was assessed at baseline using a self-administered questionnaire in Japanese based on an English version of the Western Ontario and McMaster Universities Osteoarthritis Index. The Geriatric Depression Scale was used to identify depressive symptoms in face-to-face home-visit interviews conducted 2 years later, and the association between knee pain and functional impairment and depressive symptoms was assessed using logistic regression.

RESULTS: During the 2-year follow-up, 11.9% of participants developed depressive symptoms, and pain and functional impairment were found to be associated with development of these symptoms. Pain at night while in bed (adjusted odds ratio (aOR) = 2.6, 95% confidence interval (CI) = 1.4-4.9) and difficulty putting on socks (aOR = 3.7, 95% CI: 1.8-7.5), getting into and out of a car (aOR = 3.4, 95% CI = 1.8-6.5), and taking off socks (aOR = 3.1, 95% CI = 1.5-6.5) were found to be most strongly associated with development of depressive symptoms.

CONCLUSION: Examining elderly people's responses to questions about pain at night and difficulties performing daily activities may be an efficient way of identifying those at high risk of developing depressive symptoms.