The proposed project is based on an expanded biopsycho-ecological model of illness and disability which imports concepts from gerontology (frailty), psychiatry (failure to thrive and the biopsychosocial model), rehabilitation (health environmental integration), and sociology (the social model of disability). Understanding how health conditions limit the performance of activities and the patterns and severity of the activity limitations produced is essential in developing strategies to optimize function, independent living, and quality-of-life. We propose an "Impairment Activity Staging System" for people 70 years of age and older living in the community who are experiencing limitations in the Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADLs). Our overall hypothesis is that both the mental and physical health conditions people view as limiting their abilities to perform activities and the particular ADL and IADL dysfunctions they experience will independently contribute to the prediction of 2- and 4-year functional recovery or decline, long term care (LTC) placement, and mortality. The specific aims are to: 1. Develop and test the validity of the hierarchical 5-level staging systems of ADL and IADL functioning. Higher and lower stages will be derived separately for the ADL and IADLs according to the most common and expected patterns of functional decline and recovery. 2. Derive and test the validity of a 4-dimensional impairment classification scheme that groups the mental and physical health conditions people list as most responsible for causing their ADL or IADL limitations. Assignment to each dimension will be based on knowledge about pathology according to organ involvement (brain, neuro-musculoskeletal, cardiopulmonary, etc.), potential for severity, typical progression, and likelihood of mortality. 3. Test the independent contributions of the impairment and activity staging components of the full "Impairment Activity Staging System" to predict 2- and 4-year functional recovery or decline, LTC placement, and mortality. The full classification will be assumed valid if each component shows cross sectional and predictive associations with concepts hypothesized to be clinically logically related to it, and if the health conditions and functional activity elements together prove to be more prognostic than either element alone. PUBLIC HEALTH RELEVANCE: A 2007 Institute of Medicine (IOM) report called for the creation of a comprehensive disability monitoring system applying international classification functioning, disability and health (ICF) terminology and concepts. This proposal has relevance to public health because it will help us understand the life implications of Activities of daily living (ADL) and Instrumental activities of daily living (IADL) limitation, the determinants of dynamic changes in status, and recognize both severity (the magnitude of dysfunction summarized across multiple activities) and the type of limitation (the particular pattern of deficit across the activities). The system will be designed to assess the status, needs, and prognosis of individual people and in addition, project the changing patterns of need in the larger population.