Advance directives for health care and research: prevalence and correlates.

Patients suffering from Alzheimer disease and other types of dementia gradually lose their decision-making capacity. Advance directives have been widely promoted as a means to maintain some control over one's life in the event of decisional incompetence. This study used data from a recent postal survey conducted in Quebec, Canada to: 1) estimate the prevalence of formal and informal advance directives for health care and research among community-dwelling older adults presumed free of cognitive deficits; and 2) characterize those who have communicated their preferences regarding health care and research participation. Prevalence rates vary from 7.4% (formal advance directives for research) to 42.3% (informal advance directives for health care). Following multivariate logistic regressions, individuals who have communicated their wishes regarding future health care were found to be older, predominantly women, and to more often know someone with cognitive impairment. Those who have expressed their wishes regarding future research involvement were more inclined to participate in research. They were also more likely to have discussed or written advance directives for health care. The finding that only a small proportion of older adults have discussed future research participation with their families points to the need to find effective ways to promote advance directives for research in this population.