Health service use among patients with chronic or multiple illnesses, and frequent attenders: secondary analysis of routine primary care data from 1996 to 2006.

Background: Little or no longitudinal data have been available to date on the utilization of primary care physicians' services, particularly by chronically ill and multimorbid patients and by those who see their primary care physician often ("frequent attenders").

Methods: We collected anonymous data on 305 896 patients from 155 primary care practices over the period 1996-2006 and analyzed them with descriptive statistics, correlations, and multiple logistic regression.

Results: Over the period of the study, patients visited their primary care physicians about 7 times per year on average. Frequent attendance, defined as 24 or more contacts per year, was not strongly associated with chronic illness or multimorbidity (r=0.19 and r=0.24, respectively) but was found to be linked to time-consuming medical services, such as detailed counseling (adjusted odds ratio [OR], 5.8) and house calls (OR, 3.5). Chronically ill patients utilized their primary care physicians' services less than we had expected. Chronic illness and multimorbidity were more common with increasing age; also correlated with age were the utilization of medical services, the number of visits to the primary care physician, and the number of visits to the primary care physician among frequent attenders.

Discussion: Although in Germany visits to physicians of all types (both primary care physicians and specialists) in private practice became more frequent in total over the period of this study, visits to primary care physicians alone did not. Frequent attenders do not necessarily have chronic illness or multimorbidity but seem to constitute a particularly problematic group. Chronic illness is not a predictor for greater utilization of primary care physicians' services.