The impact of arthritis in rural populations.

OBJECTIVE: Rural residents may experience more arthritis and disability than urban dwellers. This paper reviews data on arthritis in rural areas and describes a new study, the Johnston County Osteoarthritis Project, a population-based study of osteoarthritis [OA] of the knee and hip in rural North Carolina.
METHODS: Published reports of urban and rural comparisons of arthritis were reviewed. Data from the first 1,432 African-American and Caucasian participants in the Johnston County Osteoarthritis Project were analyzed. Radiographic knee and hip OA were defined as a Kellgren-Lawrence grade > or = 2. Functional ability was assessed by the Health Assessment Questionnaire, timed chair stands, and 8-foot walk time. Unweighted prevalences of knee and hip OA were calculated for age, sex, and racial groups. Associations between hip and knee OA, and hip and knee pain and functional ability were examined.
RESULTS: Hip OA was present in 27.9% and knee OA in 38.4% of participants. Both were strongly related to age (P < 0.0001), but only knee OA to female sex (odds ratio = 1.33, 95% confidence interval 1.05, 1.68). Neither hip OA nor knee OA was related to race. Hip OA, hip pain, knee OA, and knee pain was each associated with self-reported and observed functional ability.
CONCLUSION: Residents in rural areas may experience more arthritis and disability than previously expected. Contrary to other studies, African-American and Caucasian residents of rural Johnston County, North Carolina, have similar high rates of knee and hip OA. Further study is needed to address urban/rural differences in arthritis and its impact, with adequate control of confounders, standard definitions of rural/urban and of disease, and assessment of multiple arthritis outcomes.