We propose to continue and enhance a study that is documenting and modelling the impact over four years of joint impairment on functional disability, health care utilization and cost among an elderly sample chosen to represent a disability continuum (N=761 at baseline). The musculoskeletal status of study participants has been confirmed by baseline physical examinations, using protocols similar to those used by the HANES. Repeat functional assessments are being obtained using the GERI-AIMS (an adapted form of the AIMS) which measures self-reported musculoskeletal-specific and generic disability and observed measures. Health care utilization and costs are being tracked using HCFA MADRS tapes and participant diaries. Year 2 outcomes were obtained on 82% (N=624) of the baseline sample. Year 4 outcomes have been obtained on 91% of those eligible for measurement to date (N=318). Preliminary findings indicate that the rate of generic functional disability accelerates over time; e.g., change from Year 2 to Year 4 is larger than from baseline to Year 2. To determine whether this trend continues over time and to improve the power of our estimates of the determinants of change, we propose to add a Year 6 round of measurement for 308 anticipated survivors. We also propose to extend our analysis of costs efficiently by adding survey data on caregiver burden to the database at Year 6. The data will be used to analyze the progression of functional disability over time and its relationship to medical care utilization, nursing home admission, and caregiver burden. Specifically, the Generalized Estimation Equation (GEE) statistical model will be used in longitudinal analyses to estimate the contribution of joint impairment to current and subsequent disability and other outcomes (at baseline and Years 2, 4, and 6) in the context of a model of disability that controls for other comorbidities and sociodemographic variables, as well as mediating factors, such as arthritis pain, anxiety, and depression.