To determine the validity of standardized screening assessments of cognitive functioning to detect neuropsychological impairment evaluated using a comprehensive battery in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA).
This is a cross-sectional study using a combined cohort of 139 persons with SLE and 82 persons with RA. Screening cut points were empirically derived using receiver operating characteristic curves and threshold selection methods. Screening measures included the Hopkins Verbal Learning Test-Revised (HVLT-R) learning and delayed recall indices and phonemic fluency, a composite measure of the 3 cognitive screening tests, and the Perceived Deficits Questionnaire-Short Form (PDQ-SF), a self-report measure of cognitive symptoms. A comprehensive neuropsychological battery was administered as the "gold standard" index of neuropsychological impairment.
Rates of neuropsychological impairment were 27% and 15% for the SLE and RA cohorts, respectively. Optimal threshold estimations were derived for 5 screening techniques. The HVLT-R learning and phonemic fluency indices yielded the greatest sensitivity at 81%. The PDQ-SF yielded the lowest sensitivity at 52%. All measures were significantly associated with neuropsychological impairment after controlling for relevant sociodemographic covariates and depression.
These results suggest that telephone-administered screening techniques may be useful measures to identify persons with neuropsychological impairment. Specifically, measures of phonemic fluency and verbal learning appeared to be most sensitive and least likely to misclassify impaired individuals as cognitively intact. Self-reported questionnaires may have relatively decreased sensitivity compared to standardized interviewer-administered cognitive measures.