With the US health care system rapidly undergoing organizational changes that will have an impact on the delivery of primary care, a better understanding is needed of primary care services provided by generalist and specialist physicians. For this reason, we used the National Ambulatory Medical Care Survey (NAMCS) to examine changes in the frequency with which patients visited generalists and specialists for primary care services between 1997 and 2007.
We performed a cross-sectional analysis using data from the 1999 and 2007 NAMCS.1 NAMCS is a survey of outpatient offices of non–federally employed physicians who are principally engaged in patient care activities. The primary variable of interest was whether the physician visit was for a primary care service, as determined using the Reason for Visit (RFV) code. The RFV code represents the patient's complaint, symptom, or other reason for the visit in the patient's own words. For analytic purposes, we created 2 categories of visits for primary care services using the RFV variable: (1) common symptoms and diseases, such as fever, nasal congestion, anemia, and asthma and (2) preventive examinations, which included only general medical examinations. Additional details are provided in the technical eAppendix.
We categorized physicians into 4 groups: (1) primary care physicians, (2) internal medicine subspecialists, (3) obstetricians and gynecologists (Ob-Gyns), and (4) all other specialists. We used descriptive statistics to characterize visits for primary care services by physician specialty, overall and stratified by common symptoms and diseases and preventive examinations, in 1999 and 2007. All analyses took into account the complex survey design and weighted sampling probabilities of the data set and were performed using Stata statistical software, version 11.0 (Stata Corp).
There were 8730 and 12 229 unweighted visits among patients 18 years or older for primary care services related to symptoms, diseases, and general preventive care in 1999 and 2007, respectively, representing approximately 746 million visits to outpatient offices in both years combined (Table). Overall, the pattern of visits for primary care services was similar across physician specialties in 1999 and 2007. More than half of visits for primary care services in both years were to primary care physicians and did not change significantly from 1999 to 2007 (59.0% and 58.8%, respectively; P = .95). The proportion of visits for primary care services to specialist physicians was also unchanged, including internal medicine subspecialists (8.9% and 9.8%; P = .64), Ob-Gyns (4.7% and 3.6%; P = .21), and other specialist physicians (27.4% and 27.8%; P = .90).
For primary care visits for common symptoms and diseases, between 1999 and 2007, there was no change in the proportion of visits to primary care physicians (58.1% and 57.2%, respectively; P = .79), internal medicine subspecialists (9.1% and 9.6%; P = .82), Ob-Gyns (3.4% and 2.8%; P = .36) or other specialist physicians (29.4% and 30.4%; P = .73).
For primary care visits for preventive examinations, between 1999 and 2007, we observed a non–statistically significant increase in the proportion of visits to primary care physicians (66.3% and 71.2%, respectively; P = .44) and internal medicine subspecialists (7.1% and 11.9%; P = .22). In contrast, we observed a non–statistically significant decrease in the proportion of visits to Ob-Gyns (16.1% and 10.0%; P = .13) and other specialist physicians (10.5% and 6.8%; P = .39).
Examining data from a nationally representative sample of outpatient visits for primary care services, we found that fewer than two-thirds took place with primary care physicians in 1999, a proportion which remained essentially unchanged as of 2007. These findings inform our understanding of the current role primary care physicians are playing within the US health care system and raise concerns about the potential inefficiencies between primary care physician supply and demand. Two potential explanations deserve special consideration. First, patients have been shown to prefer specialist physician care and believe that specialists are better able to treat specific conditions.2,3 These preferences and beliefs may drive some patients to seek all of their care from specialists, including basic primary care services. Second, the well-documented shortage of primary care physicians in the United States4-6 may have led patients to obtain primary care services from specialist physicians. More research is needed to determine the extent to which patient preference and availability of primary care physicians, or other factors, determine where patients receive primary care services.
This study was limited to non–hospital-based ambulatory care and did not capture care provided by midlevel health care providers, such as nurses and physician assistants. Also, we could not determine the appropriateness of choosing to visit a primary care physician or a specialty physician for the primary care services we examined. Nevertheless, our finding that nearly 40% of visits for primary care services were with specialist physicians suggests current and continued inefficiency in the delivery of primary care services. A better coordinated system will likely involve realigning patient preferences along with increasing the primary care work force.
Correspondence: Dr Kale, Division of General Internal Medicine, Department of Medicine, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1087, New York, NY 10029 (firstname.lastname@example.org).
Published Online: August 20, 2012. doi:10.1001/archinternmed.2012.3207
Author Contributions:Study concept and design: Kale, Federman, and Ross. Acquisition of data: Kale. Analysis and interpretation of data: Kale, Federman, and Ross. Drafting of the manuscript: Kale. Critical revision of the manuscript for important intellectual content: Federman and Ross. Statistical analysis: Kale and Federman. Study supervision: Federman and Ross.
Financial Disclosure: Dr Ross has received compensation as a board member for FAIR Health Inc Scientific and has received grants from Medtronic Inc and Pew Charitable Trusts.
Funding/Support: This project was not supported by external funds. Dr Kale is supported by the Mount Sinai Primary Care Research Fellowship, funded by the Health Resources and Services Administration through the Ruth K. Kirchstein National Research Service Award. Dr Ross is currently supported by the National Institute on Aging (grant No. K08 AG032886) and by the American Federation of Aging Research through the Paul B. Beeson Career Development Award Program and has received grants from the Centers for Medicare and Medicaid Services.
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