The feasibility of using quick dementia rating system in clinical practice: Results of a multi-center prospective validation study

Abstract

Objective. To determine the sensitivity and specificity of the Quick Dementia Rating System (QDRS), a 10-item questionnaire for the assessment of cognitive, behavioral, and functional impairments, in the Russian population. Material and methods. The authors examined 2357 patients,1479 female (63%) and 878 male (37%), with subjective cognitive impairment (SCI), mild cognitive impairment (MCI) or dementia. Their average age was 73,1±9,7. All patients were assessed using QDRS and MMSE on baseline visits and reassessed after 1, 3, and 6 months. Results. The sensitivity and specificity of QDRS were 79,2% and 81,2%, respectively, at cut-interval of more than 7 points. There was a strong inverse correlation between QDRS and MMSE indicators (r=–0,740). QDRS was the most sensitive for the detection of severe dementia (sensitivity of 78,2% and specificity of 85,2%), while for mild and moderate dementia the sensitivity was high (79,4% and 81,6%) and specificity was low (56,6% and 61,9%, respectively). The sensitivity and specificity of separate subtests were variable. Conclusion. The QDRS sensitivity and specificity allow recommending it for clinical practice. The questionnaire is the most sensitive to detect more severe cognitive impairment.