The Mini-Mental State Examination as a diagnostic and screening test for delirium: systematic review and meta-analysis

Abstract

ObjectiveTo analyse the evidence concerning the accuracy of the Mini-Mental State Examination (MMSE) as a diagnostic and screening test for the presence of delirium in adults. MethodTwo authors searched MEDLINE, PsychINFO and EMBASE from inception till March 2014. Articles were included that investigated the diagnostic validity of the MMSE to detect delirium against standardised criteria. A diagnostic validity meta-analysis was conducted. ResultsThirteen studies were included representing 2017 patients in medical settings of whom 29.4% had delirium. The meta-analysis revealed the MMSE had an overall sensitivity and specificity estimate of 84.1% and 73.0%, but this was 81.1% and 82.8% in a subgroup analysis involving robust high quality studies. Sensitivity was unchanged but specificity was 68.4% (95% CI=50.9–83.5%) in studies using a predefined cutoff of <24 to signify a case. In high-risk samples where delirium was present in 25% of patients, then the Positive predictive value and Negative predictive value would be 50.9% (48.3–66.2%) and 93.2% (90.0–96.5%). ConclusionThe MMSE cannot be recommended as a case-finding confirmatory test of delirium, but may be used as an initial screen to rule out high scorers who are unlikely to have delirium with approximately 93% accuracy.