Concurrent validity of a computer-based cognitive screening tool for use in adults with HIV disease

As the incidence of HIV-associated dementia has decreased, the survival of HIV-infected individuals with milder forms of cognitive impairment has increased. Detecting this milder impairment in its earliest stages has great clinical and research importance. We report here the results of an initial evaluation of the Computer Assessment of Mild Cognitive Impairment (CAMCI(®)), a computerized screening tool designed to assess abnormal cognitive decline with reduced respondent and test administrator burden. Fifty-nine volunteers (29 HIV infected; age=50.9 years; education=14.9 years; 36/59 males) completed the CAMCI(®) and a battery of neuropsychological tests. The CAMCI was repeated 12 and 24 weeks later. The results from the CAMCI were compared to Global and Domain Impairment scores derived from the full neuropsychological test battery. The CAMCI detected mild impairment (compared with normal and borderline test performance) with a sensitivity of 0.72, specificity of 0.97, positive predictive rate of 0.93, and a negative predictive rate of 0.89. Median stability over 12 and 24 weeks of follow-up was 0.32 and 0.46, respectively. These rates did not differ as a function of serostatus. A discriminant function analysis correctly classified 90% of the subjects with respect to their overall Global Impairment Rating from six of the CAMCI scores. This preliminary study demonstrates that the CAMCI is sensitive to mild forms of cognitive impairment, and is stable over 24 weeks of follow-up. A larger trial to obtain risk-group appropriate normative data will be necessary to make the instrument useful in both clinical practice and research (e.g., clinical trials).