The effects of patient characteristics on ambulatory test ordering

To investigate the relationship of patient characteristics and the use of ambulatory testing services, we examined patterns of test use for 351 patients with chronic uncomplicated hypertension, cared for by 30 private practice internists. We studied the use of visits and diagnostic tests in relation to patients' sex, marital status, obesity, employment status, occupational class, insurance coverage and severity of illness in terms of age, extent of blood pressure elevation and number of medications used in treatment. Testing services accounted for 63% of the total expenditure for testing and physician services. Females and patients with greater severity of disease had higher visit rates, and age was significantly related to increased test use. Marital status, obesity and socioeconomic characteristics were not strongly associated with patterns of testing. Our results suggest that patterns of testing for hypertensive patients are related to severity of illness in terms of age but not to patients' socioeconomic characteristics.