Decision-making capacity to execute a health care proxy: Development and testing of guidelines

OBJECTIVE: To evaluate the reliability and validity of guidelines to determ ine the capacity of nursing home residents to execute a health care proxy ( HCP). DESIGN: A cross-sectional study. SETTING: A 750-bed not-for-profit nursing home located in New York City. PARTICIPANTS: A random sample of 200 nursing home residents: average age, 8 7; 99% white; 83% female; average length of stay, 3.05 years; mean Mini-Men tal State Exam (MMSE) score, 15.9. MEASUREMENTS: Demographic characteristics (Minimum Data Set (MDS)); functio n and cognitive status (Institutional Comprehensive Assessment and Referral Evaluation (INCARE)); Reisberg Dementia Staging; MMSE; Minimum Data Set-Co gnitive Performance Scale (MDS-COGS) an investigator-developed measure of a nursing home resident's capacity to execute a health care proxy (Health Ca re Proxy (HCP) Guidelines.) RESULTS: The internal consistency of the decision-making scales in the HCP Guidelines, paraphrased recall and recognition, reached acceptable levels, alphas of .85 and .73, respectively. Interrater reliability estimates were .92 and .94, respectively , for the recall and recognition scales; test-ret est reliability estimates were .83 and .90. The discriminant validity of th ese scales is promising. For example, the MMSE correlation was .51 with the Recall scale and .57 with the Recognition scale. Of residents with severe cognitive impairment (MMSE < 10), 71% completed 50% or more of the scaled i tems in the HCP guidelines and 95% consistently named a proxy. CONCLUSIONS: Seventy-three percent of testable residents, approximately thr ee-quarters of whom were cognitively impaired, evidenced sufficient capacit y to execute an HCP. Of residents with severe cognitive impairment, the HCP guidelines are potentially useful in identifying those with the capacity t o execute a HCP. The guidelines are more predictive than the MMSE in identi fying residents able to execute a HCP.