For example, the diagnosis of peptic ulcer disease is considered out of domain for an OBG but in domain for a gastroenterologist, while cervical dysplasia is considered in domain for an OBG but out of domain for a gastroenterologist. We considered out of domain care as a measure of the breadth of care provided. The more out of domain care an OBG provided, the greater the degree of primary care that he or she was providing.
Analysis
We examined the distribution of out of domain visits for individual OBGs and the frequency of all diagnoses and out of domain diagnoses for OBGs in total. We also described visit volumes and percentage of out of domain visits in both rural and urban areas for OBGs and other physician specialists.
Results
Of the 328 Washington physicians in 1994 who submitted Medicare claims and were designated as OBGs by either the ABMS or the AMA masterfile, 285 were designated OBGs by both the ABMS and the AMA masterfile. These 285 OBGs treated 10,522 Medicare patients for 16,743 visits. These patients made a total of 108,720 visits to all physicians during the year. The patients of OBGs averaged 1.6 visits to them and 10.3 visits to any physician over the year. Patients who visited OBGs received 15.4% of their total health care from them.
The visit rate to OBGs (1.6) was the lowest for all the specialties studied; however, it closely resembled rates from other surgical specialties that ranged from 1.8 to 2.4 visits per patient. Medical specialists averaged 1.9 to 3.7 visits per patient, and traditional generalists ranged from 3.7 to 3.8 visits per patient. Of the specialties studied, the percentage of overall health care for patients of physicians of a certain specialty received by those physicians was the third lowest for OBGs (15.4%). This amount was similar to surgical specialists who ranged from 15.3% to 18.9%. Medical specialists ranged from 17.8% to 27.1%, and the patients who saw a family physician or general internist received more than 40% of their total health care from them during the year.
Of the 16,743 visits made to OBGs, 12.2% had diagnoses that were out of domain for the specialty Table 1. Among surgical specialists, general surgeons had the highest percentage of out of domain visits (21.9%), while others had a much lower proportion of out of domain visits (1.5% to 4.5%). Among medical specialists, pulmonologists had the highest percentage of out of domain visits (29.7%); others ranged from 1.2% to 15.0%.
Almost 12% of OBGs had more than 30% of their visits out of domain Figure 1. The median percentage of out of domain visits for individual OBGs was 6.7%. Table 1 shows that rural OBGs provided less out of domain care (8.2%) than their urban counterparts (12.9%). General surgeons were similar to OBGs in providing less out of domain care in the rural setting than urban setting. All the other specialties had the same or more out of domain care in the rural setting than in the urban setting.
Two of the 15 most frequent diagnosis clusters recorded by OBGs were for out of domain care Table 2. The general medical examination was the fifth most frequently reported diagnosis cluster and the most frequent out of domain diagnosis cluster Table 3. Hypertension was the other out of domain diagnosis cluster in the top 15 and comprised 9.0% of all of the out of domain diagnoses. The other out of domain problems diagnosed by OBGs include a full range of primary care conditions.
Discussion
Our study demonstrates that during 1994, the large majority of OBGs provided a limited amount of nongynecologic care to their elderly patients. This is consistent with the findings of other studies examining the scope of OBGs’ practices and suggests that in general OBGs were not serving as primary care providers to their elderly patients.11,13-15,17,18
The visit rates to OBGs were more similar to surgical subspecialties than to the traditional primary care specialties. The number of visits per Medicare patient to OBGs was 1.6, the lowest of the specialties studied and very different from that of traditional primary care specialists (3.7 to 3.8 per patient). Patients of OBGs received 15.4% of their total health care from OBGs, which was much lower than the amount of overall health care that traditional generalists provided to their patients (42.0%-42.9%). This suggests that OBGs were primarily seeing elderly patients in consultation for gynecologic problems. This is consistent with a number of studies that have demonstrated that elderly women are less likely to receive care from OBGs.10,12,19-22