Defining severe dementia with the Minimum Data Set

Accurately defining severe dementia is important for care and prognosis, but is not explicitly included in the Minimum Data Set (MDS).

To define severe dementia using the MDS, we used data for nursing home residents with moderate to severe dementia.

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.

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.

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.