Prevalence of knee osteoarthritis in a suburban, Srilankan, adult female population: a population-based study.

INTRODUCTION: Prevalence of knee osteoarthritis (KOA) has not been assessed in Sri Lanka, since 2006. This study aimed to determine the prevalence of clinical KOA and radiographic KOA and to assess the severity of it, among adult females of a suburban setting in Sri Lanka. METHODS: A cross-sectional survey was conducted among a representative sample of 666 females aged 50 years or more resident in Pita Kotte Medical Officer of Health area. Four physiotherapy graduates applied American College of Rheumatology (ACR) criteria by performing the clinical assessment in the households. Participants with clinical knee osteoarthritis were referred for radiography to identify radiographic osteoarthritis and to assess severity. Age standardized prevalence of clinical KOA for Sri Lanka was estimated based on population statistics of 2001 Census. RESULTS: Study included 666 adult females with a response rate of 99.4%. The mean age was 63.3 years (±9.29 years). A total of 134 were found to satisfy ACR criteria resulting in a crude prevalence of clinical KOA of 20.1% (95% CI 17.0%-23.2%). Estimated age standardized prevalence of clinical KOA for Sri Lanka was 21.8% (95% CI 21.7-21.9). Among those with clinical KOA 58.9% showed radiographic KOA and the prevalence of moderate/severe KOA among those with clinical KOA was 29.9%. CONCLUSION AND RECOMMENDATIONS: Prevalence of clinical KOA among the adult females over 50 years was high with considerable proportion of them being moderate /severe KOA. These findings should be used to advice the health authorities regarding improving preventive and curative services for KOA.