Antivirals and antibiotics for influenza in the United States, 1995–2002

Purpose To measure the rates of antiviral and antibiotic prescribing for patients diagnosed with influenza in the United States. Methods We performed a retrospective analysis of visits to ambulatory clinics and emergency departments in the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) with a diagnosis of influenza that occurred in seven influenza seasons between 1 October 1995 and 31 May 2002 ( n  = 1216). Results There were an estimated 22 million visits (95%CI, 17–26 million visits) with a diagnosis of influenza to community ambulatory clinics (88% of visits), hospital ambulatory clinics (3%) and emergency departments (9%) in the United States between the 1995–1996 and the 2001–2002 influenza seasons, inclusive. The sample was 63% adults, 44% male and 84% white. Physicians prescribed antivirals in 19% of visits and antibiotics not associated with an antibiotic‐appropriate diagnosis in 26% of visits. In multivariable modeling, independent predictors of antiviral prescribing were adult age (OR, 2.1; 95%CI, 1.1–4.0) and Medicare insurance (OR, 0.1 compared to private insurance; 95%CI, 0.0–0.6). Antiviral prescribing was marginally associated with influenza season (OR, 1.2 per influenza season; 95%CI, 1.0–1.4). Independent predictors of antibiotic prescribing were influenza season (OR, 0.8 per influenza season; 95%CI, 0.7–0.9), male sex (OR, 0.6; 95%CI, 0.4–0.9), adult age (OR, 2.3; 95%CI, 1.2–4.2) and emergency department visits (OR, 0.5 compared to community ambulatory visits; 95%CI, 0.3–0.8). Conclusions Physicians prescribed antiviral medications to 19% of patients they diagnosed with influenza; the proportion that would have been clinically appropriate is unknown. In contrast, physicians prescribed apparently inappropriate antibiotics to 26% of these same patients, a rate that, encouragingly, decreased over time. Copyright © 2005 John Wiley & Sons, Ltd.