Using routine documentation of medical care to observe physician behavior

This observational study compared the utilization of pulmonary function tests (PFTs) for outpatients at community hospitals in New Hampshire in 1975 and 1980. It was hypothesized that if preliminary care physicians were shifting toward using PFTs for early detection of chronic obstructive airway disease (COAD), an increase in the number of tests ordered, a decrease in the mean age of patients tested, and an increase in the mean lung functions (FEV1/FVC) would be observed. For hospitals providing data for 1975 and 1980, 85% showed an increase in the number of outpatient tests ordered (p = 0.002), the mean age of outpatients tested decreased at 75% of the hospitals (p = 0.019), and the mean FEV1/FVC increased at 67% of the hospitals (p = 0.014). The hypotheses thus confirmed, it is concluded that New Hampshire physicians are using PFTs for early detection of COAD.