Validity and Responsiveness to Change of Clinically Derived MDS Scales in Alzheimer Disease Outcomes Research

Abstract

This analysis assessed 3 subscales derived from the nursing home Minimum Data Set (MDS), the Cognitive Performance Scale (CPS), Depression Rating Scale (DRS), and Aggressive Behavior Scale (ABS), as outcome measures in clinical trials of long-term care residents with Alzheimer disease (AD). A total of 26 patients with moderate-to-severe AD and agitation/aggression enrolled in a trial of memantine were assessed using the Mini-Mental State Examination (MMSE), Neuropsychiatric Inventory Nursing Home Version (NPI-NH), and the Cohen-Mansfield Agitation Inventory (CMAI) administered by trained researchers. MDS data were collected as part of their standard clinical care. The MDS subscales correlated significantly with their corresponding research scales: CPS and MMSE (r = -0.57, P = .003); DRS and NPI-NH total (r = 0.42, P = .038); DRS and NPI-NH depression (r = 0.41, P = .04), and ABS and CMAI (r = 0.54, P = .004). DRS and ABS scores did not change significantly from baseline to 3 months though the NPI-NH and CMAI did, indicating limited sensitivity to change. This suggests that the MDS subscales measure comparable aspects of cognitive function and depressive and agitated/aggressive behavior as the MMSE, NPI-NH, and CMAI. However, this analysis also suggests that sensitivity to change of the DRS and ABS may be limited compared to the NPI-NH and CMAI. As these findings are preliminary, further research is needed to determine the utility of MDS scales in outcomes research.