Diagnostic Accuracy of the Telephone Interview for Cognitive Status for the Detection of Dementia in Primary Care

Abstract

PURPOSE Cognitive diagnostic work-up in primary care is not always physically feasible, owing to chronic disabilities and/or travel restrictions. The identification of dementia might be facilitated with diagnostic instruments that are time efficient and easy to perform, as well as useful in the remote setting. We assessed whether the Telephone Interview for Cognitive Status (TICS) might be a simple and accurate alternative for remote diagnostic cognitive screening in primary care. METHODS We administered the TICS (range, 0-41) for 810 of 1,473 older people aged 84.5 (SD, 2.4) years. We scrutinized electronic health records for participants with TICS scores ≤30 and for a random sample of participants with TICS scores >30 for a dementia diagnosis using all data from the Prevention of Dementia by Intensive Vascular Care (preDIVA) trial for 8-12 years of follow-up. We used multiple imputation to correct for verification bias. RESULTS Of the 810 participants, 155 (19.1%) had a TICS score ≤30, and 655 (80.9%) had a TICS score >30. Electronic health records yielded 8.4% (13/154) dementia diagnoses for participants with TICS ≤30 vs none with TICS >30. Multiple imputation for TICS >30 yielded a median of 7/655 (1.1%; interquartile range, 5-8) estimated dementia cases. After multiple imputation, the optimal cutoff score was ≤29, with mean sensitivity 65.4%, specificity 87.8%, positive predictive value 11.9%, negative predictive value 99.0%, and area under the curve 77.4% (95% CI, 56.3%-90.0%). CONCLUSIONS In the present older population, the TICS performed well as a diagnostic screening instrument for excluding dementia and might be particularly useful when face-to-face diagnostic screening is not feasible in family practice or research settings. The potential reach to large numbers of people at low cost could contribute to more efficient medical management in primary care.