Adam L. Hersh

IMPORTANCE: The National Action Plan for Combating Antibiotic-Resistant Bacteria set a goal of reducing inappropriate outpatient antibiotic use by 50% by 2020, but the extent of inappropriate outpatient antibiotic use is unknown. OBJECTIVE: To estimate the rates of outpatient oral antibiotic prescribing by age and diagnosis, and the estimated portions of antibiotic use that may be inappropriate in adults and children in the United States. DESIGN, SETTING, AND PARTICIPANTS: Using the 2010-2011 National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey, annual numbers and population-adjusted rates with 95% confidence intervals of ambulatory visits with oral antibiotic prescriptions by age, region, and diagnosis in the United States were estimated. EXPOSURES: Ambulatory care visits. MAIN OUTCOMES AND MEASURES: Based on national guidelines and regional variation in prescribing, diagnosis-specific prevalence and rates of total and appropriate antibiotic prescriptions were determined. These rates were combined to calculate an estimate of the appropriate annual rate of antibiotic prescriptions per 1000 population. RESULTS: Of the 184,032 sampled visits, 12.6% of visits (95% CI, 12.0%-13.3%) resulted in antibiotic prescriptions. Sinusitis was the single diagnosis associated with the most antibiotic prescriptions per 1000 population (56 antibiotic prescriptions [95% CI, 48-64]), followed by suppurative otitis media (47 antibiotic prescriptions [95% CI, 41-54]), and pharyngitis (43 antibiotic prescriptions [95% CI, 38-49]). Collectively, acute respiratory conditions per 1000 population led to 221 antibiotic prescriptions (95% CI, 198-245) annually, but only 111 antibiotic prescriptions were estimated to be appropriate for these conditions. Per 1000 population, among all conditions and ages combined in 2010-2011, an estimated 506 antibiotic prescriptions (95% CI, 458-554) were written annually, and, of these, 353 antibiotic prescriptions were estimated to be appropriate antibiotic prescriptions. CONCLUSIONS AND RELEVANCE: In the United States in 2010-2011, there was an estimated annual antibiotic prescription rate per 1000 population of 506, but only an estimated 353 antibiotic prescriptions were likely appropriate, supporting the need for establishing a goal for outpatient antibiotic stewardship.

CONTEXT: Postmenopausal hormone therapy use increased dramatically during the past 2 decades because of a prevailing belief in its health benefits. Recent evidence from randomized trials published in July 2002 demonstrated adverse cardiovascular disease events and other risks with hormone therapy in the form of oral estrogen combined with progestin. OBJECTIVE: To describe patterns of hormone therapy use from 1995 until July 2003, including the impact of recent evidence. DESIGN, SETTING, AND POPULATION: Two databases were used to describe national trends in hormone therapy use from January 1995 to July 2003. The National Prescription Audit database provided data on the number of hormone therapy prescriptions filled by retail pharmacies and the National Disease and Therapeutic Index database provided data on patient visits to office-based physicians during which hormone therapy was prescribed. MAIN OUTCOME MEASURES: Annual number of hormone therapy prescriptions and characteristics of visits to physicians during which hormone therapy was prescribed. RESULTS: Annual hormone therapy prescriptions increased from 58 million in 1995 to 90 million in 1999, representing approximately 15 million women per year, then remained stable through June 2002. Adoption of new oral estrogen/progestin combinations, primarily Prempro, accounted for most of this growth. Obstetrician/gynecologists provided more than 70% of hormone therapy prescriptions, and more than one third of patients were older than 60 years. Following the publication of trial results in July 2002, hormone therapy prescriptions declined in successive months. Relative to January-June 2002, prescriptions from January-June 2003 declined by 66% for Prempro and 33% for Premarin. Small increases were observed in vaginal formulations and in new prescriptions for low-dose Premarin. If prescription rates observed through July 2003 remain stable, a decline to 57 million prescriptions for 2003, similar to the rate in 1995, is projected. CONCLUSIONS: Clinical practice responded rapidly to recent evidence of harms associated with hormone therapy. Since July 2002, many patients have discontinued hormone therapy or are tapering to lower doses.

BACKGROUND: Antibiotics are commonly prescribed for children with conditions for which they provide no benefit, including viral respiratory infections. Broad-spectrum antibiotic use is increasing, which adds unnecessary cost and promotes the development of antibiotic resistance. OBJECTIVE: To provide a nationally representative analysis of antibiotic prescribing in ambulatory pediatrics according to antibiotic classes and diagnostic categories and identify factors associated with broad-spectrum antibiotic prescribing. PATIENTS AND METHODS: We used the National Ambulatory and National Hospital Ambulatory Medical Care surveys from 2006 to 2008, which are nationally representative samples of ambulatory care visits in the United States. We estimated the percentage of visits for patients younger than 18 years for whom antibiotics were prescribed according to antibiotic classes, those considered broad-spectrum, and diagnostic categories. We used multivariable logistic regression to identify demographic and clinical factors that were independently associated with broad-spectrum antibiotic prescribing. RESULTS: Antibiotics were prescribed during 21% of pediatric ambulatory visits; 50% were broad-spectrum, most commonly macrolides. Respiratory conditions accounted for >70% of visits in which both antibiotics and broad-spectrum antibiotics were prescribed. Twenty-three percent of the visits in which antibiotics were prescribed were for respiratory conditions for which antibiotics are not clearly indicated, which accounts for >10 million visits annually. Factors independently associated with broad-spectrum antibiotic prescribing included respiratory conditions for which antibiotics are not indicated, younger patients, visits in the South, and private insurance. CONCLUSIONS: Broad-spectrum antibiotic prescribing in ambulatory pediatrics is extremely common and frequently inappropriate. These findings can inform the development and implementation of antibiotic stewardship efforts in ambulatory care toward the most important geographic regions, diagnostic conditions, and patient populations.

BACKGROUND: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as a common cause of skin and soft-tissue infections (SSTIs) in the United States. It is unknown whether this development has affected the national rate of visits to primary care practices and emergency departments (EDs) and whether changes in antibiotic prescribing have occurred. METHODS: We examined visits by patients with SSTIs to physician offices, hospital outpatient departments, and EDs using the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey from 1997 to 2005. We estimated annual visit rates for all SSTIs and a subset classified as abscess/cellulitis. For abscess/cellulitis visits, we examined trends in characteristics of patients and clinical settings and in antibiotic prescribing. RESULTS: Overall rate of visits for SSTIs increased from 32.1 to 48.1 visits per 1000 population (50%; P = .003 for trend), reaching 14.2 million by 2005. More than 95% of this change was attributable to visits for abscess/cellulitis, which increased from 17.3 to 32.5 visits per 1000 population (88% increase; P < .001 for trend). The largest relative increases occurred in EDs (especially in high safety-net-status EDs and in the South), among black patients, and among patients younger than 18 years. Use of antibiotics recommended for CA-MRSA increased from 7% to 28% of visits (P < .001) during the study period. Independent predictors of treatment with these antibiotics included being younger than 45 years, living in the South, and an ED setting. CONCLUSIONS: The incidence of SSTIs has rapidly increased nationwide in the CA-MRSA era and appears to disproportionately affect certain populations. Although physicians are beginning to modify antibiotic prescribing practices, opportunities for improvement exist, targeting physicians caring for patients who are at high risk.

OBJECTIVES: To determine patterns of ambulatory antibiotic prescribing in US adults, including the use of broad-spectrum versus narrow-spectrum agents, to provide a description of the diagnoses for which antibiotics are prescribed and to identify patient and physician factors associated with broad-spectrum antibiotic prescribing. METHODS: We used data for patients aged ≥ 18 years from the National Ambulatory and National Hospital Ambulatory Medical Care Surveys (2007-09). These are nationally representative surveys of patient visits to offices, hospital outpatient departments and emergency departments (EDs) in the USA, collectively referred to as ambulatory visits. We determined the types of antibiotics prescribed, including the use of broad-spectrum versus narrow-spectrum antibiotics, and examined prescribing patterns by diagnoses. We used multivariable logistic regression to identify factors associated with broad-spectrum antibiotic prescribing. RESULTS: Antibiotics were prescribed during 101 million (95% CI: 91-111 million) ambulatory visits annually, representing 10% of all visits. Broad-spectrum agents were prescribed during 61% of visits in which antibiotics were prescribed. The most commonly prescribed antibiotics were quinolones (25% of antibiotics), macrolides (20%) and aminopenicillins (12%). Antibiotics were most commonly prescribed for respiratory conditions (41% of antibiotics), skin/mucosal conditions (18%) and urinary tract infections (9%). In multivariable analysis, among patients prescribed antibiotics, broad-spectrum agents were more likely to be prescribed than narrow-spectrum antibiotics for respiratory infections for which antibiotics are rarely indicated (e.g. bronchitis), during visits to EDs and for patients ≥ 60 years. CONCLUSIONS: Broad-spectrum agents constitute the majority of antibiotics in ambulatory care. More than 25% of prescriptions are for conditions for which antibiotics are rarely indicated. Antibiotic stewardship interventions targeting respiratory and non-respiratory conditions are needed in ambulatory care.