The first part of this paper provides a general outline of objectives and methods of the Internal Medicine and Geriatrics Unit of the Berlin Aging Study (BASE). Based on a multi-dimensional conceptualization of health, objective and laboratory data collected about different organ systems, e.g. cardiovascular and musculoskeletal, and functional capacity are complemented by qualitative clinical diagnoses and judgements as well as self-reported health problems and functional limitations. Some of the central questions that can be addressed using these data relate to understanding the nature and processes of differential ageing. The second part of the paper includes initial analyses of inter-individual health differences in advanced old age (70 to 105 years). Initial findings indicated that heterogeneity in somatic morbidity and functional capacity was at least as large in old adults (70 to 84 years) as in very old adults (85 to 105 years), even though higher rates of somatic morbidity and lower levels of functional capacity were observed in the very old. Chronological age and morbidity as well as psychosocial and demographic factors were found to be independent predictors of functional capacity in advanced old age. Additionally, the relative importance of psychosocial factors was found to be a function of age with lower predictive ability among the very old. In conclusion, these initial findings support the hypothesis of significant health differences in advanced old age due to differential ageing.

In the present paper the focus is on structural aspects of everyday competence and its relationship with various personal resources, such as health, social status, self concept and cognition. The findings support the hypothesis that two distinct, albeit intercorrelated, components of everyday competence are differentially related to the various resources examined in this paper. The two components are a basic level of competence (BaCo) which is defined mainly by self-care related activities, and an expanded level of competence (ExCo) associated mostly with leisure and social activities and advanced instrumental activities of daily living. In general, BaCo is more strongly related to health-related resources, and ExCo is more strongly associated with behavioural, psychological and social resources. 90.6% of the reliable variance in ExCo and 82.4% in BaCo are explained by these selected resources. Furthermore, all of the age-related variance in everyday competence is accounted for by these health-related and socio-behavioural resources.