Background: Arthritis and other rheumatic conditions are a common cause of disability among adults in the United States. Telephone interviews of the state-based Behavioral Risk Factor Surveillance System (BRFSS) are used by states and territories to estimate the prevalence of arthritis. The purpose of this study was to assess the validity and reliability of the 1996-2001 BRFSS arthritis case definition in a senior center population.
Methods: A total of 487 respondents at selected senior centers in Georgia were surveyed by telephone, evaluated 3 to 4 weeks later by board-certified rheumatologists, and completed a written survey in 2000 to 2001. Using the rheumatologists' summary assessment "Does this person have arthritis or a related condition" as the standard, the sensitivity and specificity of the BRFSS arthritis case definitions were calculated. Reliability for the BRFSS arthritis case definition was also calculated by comparing responses to the telephone survey with responses to a written survey.
Results: Sensitivity was 70.8% (95% confidence interval [CI]=65.9-75.6), and the specificity was 70.3% (95% CI=62.9-77.8). The agreement between the telephone and written responses indicating self-reported arthritis was high (kappa=0.68). Analyses were conducted in 2002 to 2004.
Conclusions: Self-reported arthritis in the 1996-2001 BRFSS was highly reliable, and moderately sensitive and specific among these senior center participants.