National Ambulatory Medical Care Survey: 2001 summary.

OBJECTIVE: This report describes ambulatory care visits made to physician offices in the United States. Statistics are presented on selected characteristics of the physician's practice, the patient, and the visit. Results highlighting new items on continuity of care are presented. They include whether the visit was the first or a followup for a problem, number of visits to this provider in the past 12 months for established patients, and whether other physicians shared care for the patient's problem. The report also highlights estimates of practice characteristics for office-based physicians.
METHODS: The data presented in this report were collected from the 2001 National Ambulatory Medical Care Survey (NAMCS). NAMCS is part of the ambulatory care component of the National Health Care Survey that measures health care utilization by various types of providers. NAMCS is a national probability sample survey of visits to office-based physicians in the United States. Sample data are weighted to produce annual national estimates. Selected trends from the 1992 and 1997 NAMCS are also presented.
RESULTS: During 2001, an estimated 880.5 million visits were made to physician offices in the United States, an overall rate of 314.4 visits per 100 persons. From 1992 through 2001, the visit rate for persons 45 years of age and over increased by 17%, from 407.3 to 478.2 visits per 100 persons. The mean age of patients at each office visit has steadily increased from 1992 through 2001 as has the mean number of diagnoses rendered and the overall drug mention rate. The visit rate to physician offices in metropolitan statistical areas (MSAs) (338.3 visits per 100 persons) was significantly larger than the rate in non-MSAs (218.0 visits per 100 persons). Females had a higher visit rate compared with males, and white persons had a higher rate than black or African-American persons. Half of all office visits were to the patient's primary care physician (PCP). Of the visits to physicians other than the patient's PCP, about one-third (32.6 percent) were referrals. About 1 in 10 office visits were made by new patients (11.8 percent), down 20% since 1992. More than one physician shared the care for the patient's condition at about one-fifth of the office visits. Of all visits made to offices in 2001, 58.8 percent listed private insurance as the primary expected source of payment, followed by Medicare (21.8 percent) and Medicaid and/or State Children's Health Insurance Program (7.2 percent). For preventive care visits, the female visit rate was over 75% higher than the rate for males (67.1 versus 37.7 visits per 100 persons). Essential hypertension, arthropathies, acute upper respiratory infection, and diabetes mellitus were the leading illness-related primary diagnoses. There were an estimated 99.8 million injury-related visits in 2001, or 35.6 visits per 100 persons. Diagnostic and screening services were ordered or provided at 82.8 percent of visits, therapeutic and preventive services were ordered or provided at 41.4 percent of visits, and medications were prescribed or provided at 61.9 percent of visits. On average, 2.4 medications were ordered or provided at each office visit with any mention of a medication. The leading therapeutic class for drugs mentioned at office visits included cardiovascular-renal drugs (14.7 percent of mentions) and pain-relieving drugs (12.1 percent of mentions). A physician was seen at a majority of visits (95.8 percent), and a registered or licensed practical nurse was seen at 31.3 percent of visits. From 1992 through 2001, changes were observed in the leading diagnoses, therapeutic drug classes, and drug mentions. Physician estimates revealed that primary care physicians were twice as likely as specialists to make home visits during an average week of work; when they conducted them, they made twice as many (6 versus 2-3 visits per week) as specialists. Approximately 3 in 10 physicians reported not accepting new capitated, privately insured patients, whereas only 6.8 percent did not accept noncapitated, privately insured patients.