Other assumptions for the power analyses included a two-tailed alpha = 0.05, 12 and 24 week follow-up assessments for each subject, and an attrition rate of 15%. This rate is based on our six month follow-up rates as well as our experience with other samples of community-dwelling frail elders (e.g., home care patients), where we have found that obtaining the first interview is far more difficult than following older adults overtime once they have met and talked with us. Because computer algorithms are not readily available for conducting power analyses for three-level mixed-effects models, power estimates for testing H1 and H2 are based on simulations described below, that involved 1000 simulation runs for each combination of specifications.