Validation of self-report of rheumatoid arthritis and systemic lupus erythematosus: The Women's Health Initiative.

OBJECTIVE: The Women's Health Initiative (WHI), initiated in 1993, enrolled 161,808 postmenopausal women aged 50-79 years and followed them with annual questionnaires for 8 years in order to study major causes of morbidity and mortality. Our objective was to determine the most effective and efficient means to validate self-reported rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) in the WHI.
METHODS: Data from 2 of 40 WHI clinical centers were used. Of these 7443 women, 643 self-reported RA and 106 self-reported SLE. Research coordinators contacted these women using mailers and telephone calls to obtain medical record releases and a Connective Tissue Screening Questionnaire (CSQ). Medical records were obtained on 286 self-reported RA and 34 self-reported SLE and reviewed by 3 rheumatologists blind to the self-reported diagnoses. Sensitivity, specificity, and the kappa statistic were computed to evaluate the level of agreement between self-report and chart review.
RESULTS: Self-reported RA was accurate only 14.7% (42/286 cases) of the time. Coupling the self-report to medication data improved the positive predictive value (PPV; 62.2%) and kappa (0.53), suggesting a moderate agreement to chart review. Self-reported SLE was accurate only 11.8% (4/34 cases) of the time. Coupling the self-report to medication data improved the PPV (40.0%) and kappa (0.44), suggesting a moderate agreement to chart review. The CSQ was inferior to using medication data but was substantially better than self-report alone.
CONCLUSION: The performance of disease self-report coupled with medication history in validating RA and SLE was very good and should obviate the need for time-consuming medical record reviews.