Demographic covariates included gender (0 = male; 1 = female), age, highest educational achievement (1 = 8th grade or less; 2 = some high school, but did not graduate; 3 = high school graduate or GED; 4 = some college or two year degree; 5 = four year college graduate; 6 = more than a four year college degree), number of self-reported chronic illnesses, a composite measure of disability based on modified questions from the Home Care version of the Minimum Data Set(50) and a composite subjective health score based on the Physical Summary scale of the SF-36(51) and answers to two questions: “Compared to others your age would you say your ability to care for yourself is?” and “Compared to others your age would you say your health is?” Principal components analysis indicated that these three scores formed a single component; we therefore used the mean of these scales. Finally, because participants took part in an intervention study, we included a categorical variable indicating which intervention they received (0 = standard care; 1 = health care vouchers; 2 = home care nurse; 3 = vouchers plus home care nurse).
