Study of measurement properties according to dementia diagnosis criteria of the 14-item dementia screening tool in the older adults

Abstract

This descriptive research aimed to investigate the measurement properties according to dementia diagnosis criteria of a 14-item dementia screening tool for dementia screening in older adults. The sample was 765 persons, aged 60 years or over, residing in communities in Chachoengsao and Nakhon Ratchasima Provinces. Data were collected by using a demographic questionnaire; the 14-item dementia screening tool; the MMSE-Thai-2002; the MoCA test Thai version; and Physician’s diagnosis according to DSM-5 criteria, which was used as the gold standard. Data were analyzed by using descriptive statistics. Normality test using the Kolmogorov-Smirnov test revealed that the data were normally distributed. Therefore, an analysis of measurement properties according to dementia diagnosis criteria of the 14-item dementia screening test in comparison with dementia screening standard tools and Physician’s diagnosis.

Results showed that among the 765 older adults, 5.5% were diagnosed with dementia, 85.9% were diagnosed with mild cognitive impairment (MCI), and 8.6% did not have memory issues. The 14-item dementia screening has a reliability value of 0.928. At a cut-off score of 30 points, the test showed relatively low sensitivity but high specificity and accuracy [sensitivity 10.34, specificity 94.91, Accuracy 88.5, PPV 14.29, NPV 92.81, AUC-ROC 0.535]. In the MCI group, screening sensitivity was notably high, whereas specificity and accuracy were relatively low [sensitivity 81.03, specificity 13.72, Accuracy 18.82, PPV 7.15, NPV 89.81, AUC-ROC 0.485].

Upon selecting cut-off points equal to or greater than 25 points, the MCI group demonstrated increased sensitivity, specificity, and accuracy [sensitivity 87.16, specificity 14.33, Accuracy 24.71, PPV 14.46, NPV 87.04, AUC-ROC 0.507]. Within the dementia group, specificity increased while sensitivity and accuracy decreased [sensitivity 7.34, specificity 94.82, Accuracy 82.35, PPV 19.05, NPV 86.03, AUC-ROC 0.525].

The measurement properties of the 14-item dementia screening tool are suitable for MCI screening. It can identify those at risk from those who are normal. The selection of new cut-off points directly impacts sensitivity and specificity, resulting in a trade-off pattern between the two. Therefore, the sensitivity and specificity of the 14-item tool remain limited, warranting further study and improvement.