Brief informant screening test for mild cognitive impairment and early Alzheimer's disease

Background/Aims: Recent research has attempted combinations of instruments to improve screening accuracy for mild cognitive impairment (MCI) and early Alzheimer's disease (AD). We compared Mini-Mental State Examination (MMSE), Immediate and Delayed Recall ( Logical Memory I and II; LM-I and LM-II, respectively), a single-item informant report of memory problem (IRMP), and a four-item Instrumental Activities of Daily Living (4IADL) scale, and combinations of these tests. Method: The tests were administered together with Clinical Dementia Rating (CDR) to subjects who were cognitively intact ( CDR = 0, n = 88), and with diagnoses of MCI ( CDR = 0.5, n = 37) and early AD ( CDR = 1 - 2, n = 19). Results: Screening accuracy ( receiver operating characteristic area under curve, AUC) for identifying MCI or MCI-AD was lowest for MMSE ( AUC 67.6% for MCI or 77.9% for MCI-AD), and better for IRMP (79.5 or 83.2%), 4IADL (76.9 or 84.7%), LM-I ( 81.2 or 87.1%) and LM-II (86.1 or 90.8%). Combining IRMP, 4IADL and LM-II was most accurate ( AUC 91.7% for MCI or 94.5% for MCI-AD); sensitivity: 86.5 or 89.3%; specificity: 86.4 or 88.6%. However, combining IRMP and 4IADL gave nearly as good accuracy (AUC 87.2 or 91.6%); sensitivity: 86.5 or 85.7%; specificity: 79.5 or 85.2%. Conclusion: A brief instrument combining an IRMP and 4IADL items is potentially useful in screening for MCI and early AD. Copyright (C) 2006 S. Karger AG, Basel.