Comparison of the diagnostic accuracy of the Cognitive Performance Scale (Minimum Data Set) and the Mini‐Mental State Exam for the detection of cognitive impairment in nursing home residents

Abstract

To compare the diagnostic accuracy of an outcome measurement scale of the Minimum Data Set of the Resident Assessment Instrument for nursing homes (MDS/RAI-NH), the Cognitive Performance Scale (CPS) and the Mini-Mental State Exam (MMSE) for the detection of cognitive impairment. The Cambridge Examination for Mental Disorders of the Elderly--Revised (CAMDEX-R) was used as the reference standard. This study was part of a larger prospective study (QUALIDEM) involving a diagnostic procedure and two-year follow-up on the quality of primary care for demented patients. CAMDEX-R and MDS/RAI-NH were administered to 198 residents, aged 65 or more, living in 42 low and high care institutions for aged people. Indicators of diagnostic accuracy: sensitivity, specificity, predictive values, likelihood ratios, odds ratio and area under receiver operating characteristics curve (AUC). The CAMDEX-based prevalence of cognitive impairment was 75%. The diagnostic values of a CPS score of two or more for the detection of cognitive impairment were: sensitivity = 0.81; specificity = 0.80; PPV = 0.92; NPV = 0.57. The diagnostic values of a MMSE score of less than or equal 23 were: sensitivity = 0.97; specificity = 0.59; PPV = 0.88; NPV = 0.85. For CPS, the area under the receiver operating characteristic (ROC) curve was 0.87 (95% CI, 0.81-0.91), and not significantly different (p = 0.63) from the MMSE score, 0.88 (0.83-0.93). CPS and MMSE demonstrated similar performance to detect cognitive impairment in nursing home residents.