Identifying the most efficient items from the Mini-Mental State Examination for cognitive function assessment in older Taiwanese patients

Aims. The purpose of the study was to identify the most efficient items from the Mini-Mental State Examination for assessment of cognitive function. Background. The Mini-Mental State Examination is the most frequently used cognitive screening instrument. However, the Mini-Mental State Examination has been criticized for insensitivity to mild cognitive dysfunction, limited memory assessment and variability in level of difficulty of the individual items. Method. This study used secondary data analysis. Item response theory two-parameter model was used to analyse the data from the admission assessment of mental status by the Mini-Mental State Examination for 801 patients. Results. By using item response analysis, 16 items were selected from the original 30-item Mini-Mental State Examination. The 16 items included mainly the measures of orientation, recall and attention and calculation. The internal consistency of the 16-item Mini-Mental State Examination was 0.84. The proposed new cut-off point for the 16-item Mini-Mental State Examination was 11. The correct classification rate was 0.94, the sensitivity was 100% and the specificity was 97.4%, when compared with the original 30-item Mini-Mental State Examination from the cut-off point of 24. This new cut-off point was determined for the purpose of over-identifying patients at risk so as to ensure early detection of and prevention from the onset of cognitive disturbance. Conclusion. Only a few items are needed to describe the subject's cognitive status. Using item response theory analysis, the study found that the Mini-Mental State Examination could be simplified. Relevance to clinical practice. Deleting the items with less variation makes this assessment tool not only shorter, easier to administer and less strenuous for respondents, but also enables one to maintain validity as a cognitive function test for clinical setting.