Older patients' perceptions of quality of chronic knee or hip pain: differences by ethnicity and relationship to clinical variables.

BACKGROUND: There is marked ethnic or racial disparity in the utilization of joint replacement for osteoarthritis. The reasons are not known. Pain is the reason most patients with osteoarthritis seek care. Cultural and psychosocial factors influence how patients experience and express pain. We examined whether patient descriptions of chronic pain vary by ethnicity and if they correlate with important clinical measures used in arthritis care.
METHODS: Sample consisted of 300 male veterans who were > or =50 years of age with moderate to severe symptomatic knee or hip osteoarthritis. Structured surveys were used to assess patient descriptions of pain and to collect important demographic, clinical, and psychosocial variables. Factor analysis was used to assess patterns of pain description in a comparison of African-American and Caucasian patients. Pearson correlations were used to examine relationships between pain descriptions and clinical variables.
RESULTS: The two groups were similar with respect to age and other baseline clinical characteristics. A confirmatory factor analysis on quality of pain description showed that a four-factor model converged for Caucasian patients (chi square = 39.6, comparative fit index = 0.95, Tucker Lewis index = 0.93, and root mean square error of approximation = 0.047), but a three-factor model was supported by the data for African-American patients (chi square= 25.4, comparative fit index = 1.00, Tucker Lewis index = 1.05, and root mean square error of approximation < or = 0.001). Chronic pain quality descriptions correlate significantly with Western Ontario and McMaster Universities Arthritis Index scores but not with radiologic stage of disease.
CONCLUSIONS: African-American and Caucasian elderly patients with chronic knee or hip symptomatic osteoarthritis describe the quality of their pain differently. Patient descriptions of quality of chronic knee or hip pain do not correlate with radiologic stage of disease.