Outpatient visits for infectious diseases in the United States, 1980 through 1996.

BACKGROUND: Recent studies have documented increases in infectious disease mortality and in the proportion of hospitalizations attributable to infectious diseases. To further evaluate trends in the burden of infectious diseases in the United States, we analyzed data from the National Ambulatory Medical Care Survey from 1980 through 1996.
OBJECTIVE: To examine the epidemiology of and recent trends in outpatient visits for infectious diseases.
METHODS: Data were from a national probability sample of patient visits to office-based physicians. Diagnoses reported by the surveyed physicians were coded to indicate whether they were infectious or noninfectious. Infectious diseases were placed into 11 mutually exclusive categories.
RESULTS: During the course of the survey, infectious diseases accounted for 19.0% of visits to physicians, or an average of 129 million visits per year. The infectious disease visit rate was higher in females than in males (587 vs 461 per 1000 persons per year) and higher in non-Hispanic whites than in non-Hispanic blacks or Hispanics (538 vs 407 vs 485 per 1000 persons per year). The visit rate for infectious diseases was greatest in 0- to 4-year-olds. Upper respiratory tract infections accounted for the largest proportion of visits (38.0% of infectious disease visits), followed by otitis (15.1%) and lower respiratory tract infections (14.1%). The age-adjusted visit rate for infectious diseases increased from 462 visits per 1000 persons (17.5% of all visits) in 1980 to 575 (20.2%) in 1990. From 1990 to 1996, this rate declined to 483 per 1000 (18.1%).
CONCLUSIONS: Infectious diseases are responsible for a substantial proportion of outpatient visits to physicians in the United States. Upper respiratory tract infections account for the largest proportion of these visits.