Primary care safety-net delivery sites in the United States - A comparisonof community health centers, hospital outpatient departments, and physicians' offices

Context The US primary care safety net is composed of a loose network of co mmunity health centers, hospital outpatient departments, and physicians' of fices. National data on how the mix of patients and services differ across sites are needed. Objective To develop and contrast national profiles of patient and service mix for primary care. Design, Setting, and Patients Comparative analyses of 3 national surveys of primary care visits occurring in 1994: for data on physician's office visi ts, the National Ambulatory Medical Care Survey (NAMCS); for hospital outpa tient department data, the National Hospital Ambulatory Medical Care Survey (NHAMCS); and for data on community health centers, the Bureau of Primary Health Care's 1994 Survey of Visits to Community Health Centers. A time tre nd analysis also was conducted using the 1998 NAMCS and NHAMCS. Main Outcome Measures National estimates of primary care visit rates, types of patient presentation, patient case-mix, disposition of patients, and ma nagement interventions in 1994, and compared with 1998 data. Results The US population made 1.3 primary care visits per person in 1994, which accounted for 43.5% of all ambulatory visits to physicians' offices, community health centers, and hospital outpatient departments. Primary care visits per person were 20% lower for Hispanics and 33% lower for black, no n-Hispanic persons compared with white, non-Hispanic persons. Visits to com munity health centers were more likely to be made by ethnic minorities, pat ients with Medicaid or no insurance, and rural dwellers than visits made to the other delivery sites. Visits at hospital outpatient departments were m ade by sicker populations and were characterized by less continuity than th e other delivery sites. Controlling for patient mix, visits made to hospita l outpatient departments were more commonly associated with imaging studies , minor surgery, and specialty referrals than those made to physicians' off ices. In 1998, the US population made an estimated 3.4 visits per person, 4 5.6% of which were primary care visits. National estimates of primary care visit rates and patient mix and practice pattern comparisons between hospit al outpatient departments and physicians' offices were similar in 1998 and 1994. Conclusions Expanding community health centers will likely improve access t o primary care for vulnerable US populations. However, enhancing access to of physicians' offices is also needed to bolster the safety net. The greate r service intensity and poorer continuity for primary care visits in hospit al outpatient departments that we observed raises concern about the suitabi lity of these clinics as primary care delivery sites.