Defining severe dementia with the Minimum Data Set

BACKGROUND: Accurately defining severe dementia is important for care and prognosis, but is not explicitly included in the Minimum Data Set (MDS). OBJECTIVE: To define severe dementia using the MDS, we used data for nursing home residents with moderate to severe dementia. METHODS: Two cross-sectional studies enrolled 175 residents; 89 residents from one US Veterans Affairs nursing home, and 86 residents from nine Dutch nursing homes. Measurements included the Cognitive Performance Scale (CPS; range: 0-6), activities of daily living (ADL) dependency, and the Bedford Alzheimer Nursing Severity-Scale (BANS-S; range: 7-28), a staging instrument specific for severe dementia. RESULTS: Half of the residents received CPS scores of 5, and their BANS-S scores varied widely. There was fair agreement (kappa=0.36) between severe cognitive impairment as defined by the CPS (scores 5 and 6) and the BANS-S (score 17 or higher). Addition of an ADL dependency requirement to the CPS definition improved agreement (kappa=0.75). The observed patterns were similar but more obvious for US residents than for Dutch residents. CONCLUSION: Cognitively impaired residents comprise a heterogeneous group with a wide variety of function. Restriction with respect to ADL dependency allows for distinction between moderate and severe dementia. We propose the following MDS-based definition of severe dementia: a CPS score of 5 or 6 with a minimum score of at least 10 points on the MDS ADL-Short Form.