Assessing the denominator problem in community-oriented primary care.

Determination of health care needs is an essential cornerstone of community-oriented primary care (COPC). Many physicians, lacking research resources, may generalize their own patient registry data to the community. But practice populations are likely to differ significantly from community populations. This study compared demographics, health status, and medical care utilization in a sample of 990 elderly living in the community and 250 elderly patients registered at the St. Elizabeth Hospital Family Health Center in Youngstown, Ohio. The community survey and patient registries were comparable on key demographic characteristics. But statistically significant differences were observed for functional status and a number of chronic medical conditions. Comparisons of symptomatology, use of health aides, subjective health status, depression, and stress produced no significant differences. Overall health care utilization patterns were similar. The elderly family health center patients were more representative of the non-institutionalized elderly in the community than expected. And although the clinical significance remains uncertain, these findings suggest that this practice sample may be used with caution for COPC planning. But considerably more research must be undertaken in a variety of practice settings before the use of practice populations for COPC planning is widely applied.