This research is directed toward identification of the nature, determinants and consequences of the health care use behaviors manifest by older persons, the determinants and consequences of their self-rated health and the importance of these and other factors (e.g. demographic, psychosocial, environmental characteristics) for change in level of illness and occurrence and time of death. Data from the Manitoba Longitudinal Study on Aging will be used. This longitudinal study was developed by merging information from a needs assessment survey conducted in 1971 on a random sample (n=4709) of Manitoba residents 65 plus with the complete record of their health care use and mortality experience for the years 1970-1977. Health care use and mortality data were obtained from the claim files maintained for the provincial health insurance program. These data are complete and unbiased by self report, recall, and ability to pay. A measure denoting a person's "style" of physician use has been developed. Individuals are classified (very low use style to high use style) depending on how frequently they visited the physician every year over a 4-8 year period. The extent to which a person's style of physician use reflects his level of health impairment and the influence of other factors such as age, sex, self-rated health, etc., on style of use will be examined. A level of illness scale reflecting the type and number of identified illnesses constructed for each of the 8 study years from diagnostic information in the claims data will be used to investigate the nature of change in level of illness. Mortality studies will focus on identification of psychosocial risk factors, especially degree of "social connectedness", and on investigation of the extent to which style of physician use alters the relationship between level of illness and mortality.