Outpatient Antibiotic Prescribing for Acute Respiratory Infections During Influenza Seasons

Abstract

Importance: Acute respiratory infections (ARIs) are the syndrome for which antibiotics are most commonly prescribed; viruses for which antibiotics are ineffective cause most ARIs.

Objectives: To characterize antibiotic prescribing among outpatients with ARI during influenza season and to identify targets for reducing inappropriate antibiotic prescribing for common ARI diagnoses, including among outpatients with laboratory-confirmed influenza.

Design, setting, and participants: Cohort study enrolling outpatients aged 6 months or older with ARI evaluated at outpatient clinics associated with 5 US Influenza Vaccine Effectiveness Network sites during the 2013-2014 and 2014-2015 influenza seasons. All patients received influenza testing by real-time reverse transcriptase-polymerase chain reaction for research purposes only. Antibiotic prescriptions, medical history, and International Classification of Diseases, Ninth Revision diagnosis codes were collected from medical and pharmacy records, as were group A streptococcal (GAS) testing results in a patient subset.

Exposure: Visit for ARI, defined by a new cough of 7 days' duration or less.

Main outcomes and measures: Antibiotic prescription within 7 days of enrollment. Appropriateness of antibiotic prescribing was based on diagnosis codes, clinical information, and influenza and GAS testing results.

Results: Of 14 987 patients with ARI (mean [SD] age, 32 [24] years; 8638 [58%] women; 11 892 [80%] white), 6136 (41%) were prescribed an antibiotic. Among these 6136 patients, 2522 (41%) had diagnoses for which antibiotics are not indicated; 2106 (84%) of these patients were diagnosed as having a viral upper respiratory tract infection or bronchitis (acute or not otherwise specified). Among the 3306 patients (22%) not diagnosed as having pneumonia and who had laboratory-confirmed influenza, 945 (29%) were prescribed an antibiotic, accounting for 17% of all antibiotic prescriptions among patients with nonpneumonia ARI. Among 1248 patients with pharyngitis, 1137 (91%) had GAS testing; 440 of the 1248 patients (35%) were prescribed antibiotics, among whom 168 (38%) had negative results on GAS testing. Of 1200 patients with sinusitis and no other indication for antibiotic treatment who received an antibiotic, 454 (38%) had symptoms for 3 days or less prior to the outpatient visit, suggesting acute viral sinusitis not requiring antibiotics.

Conclusions and relevance: Antibiotic overuse remains widespread in the treatment of outpatient ARIs, including among patients with laboratory-confirmed influenza, although study sites may not be representative of other outpatient settings. Identified targets for improved outpatient antibiotic stewardship include eliminating antibiotic treatment of viral upper respiratory tract infections and bronchitis and improving adherence to prescribing guidelines for pharyngitis and sinusitis. Increased access to sensitive and timely virus diagnostic tests, particularly for influenza, may reduce unnecessary antibiotic use for these syndromes.

Figure 1.. Antibiotic Classes Prescribed in Pediatric and Adult Outpatients With Acute Respiratory Infections in the 2013-2014 and 2014-2015 Influenza Seasons in the US Influenza Vaccine Effectiveness Network

Acute respiratory infections are defined by cough with 7 days’ duration or less. Pediatric indicates patients aged 6 months to younger than 18 years. ^aIncludes first-generation cephalosporins and sulfonamides.

Figure 2.. Proportion of Pediatric and Adult Outpatients With Acute Respiratory Infections Who Were Prescribed Antibiotics, by Selected International Classification of Diseases, Ninth Revision Diagnostic Codes and Laboratory-Confirmed Influenza Status

Acute respiratory infections are defined by cough with 7 days’ duration or less. Pediatric indicates patients aged 6 months to younger than 18 years. ^aAll enrollees received influenza testing by real-time reverse transcriptase–polymerase chain reaction for research purposes only. At 1 site, clinicians were provided study real-time reverse transcriptase–polymerase chain reaction results for influenza within 48 hours of enrollment. Results were not available to clinicians at other sites. ^bIndicates an International Classification of Diseases, Ninth Revision diagnosis code of influenza assigned by the clinician who saw the patient. ^cAdults with a history of chronic obstructive pulmonary disease or a visit diagnosis code for chronic obstructive pulmonary disease were excluded from the analysis of bronchitis.

Figure 3.. Multivariable Analysis of Predictors of Antibiotic Prescribing Among Persons With Acute Respiratory Infections and Assigned Diagnosis Codes for Which Antibiotics Are Not Indicated (Tier 3 Diagnoses Only)

^aBy International Classification of Diseases, Ninth Revision diagnosis code. ^bIndicates an International Classification of Diseases, Ninth Revision code diagnosis of influenza, not real-time reverse transcriptase–polymerase chain reaction confirmation of influenza. ^cIndicates real-time reverse transcriptase–polymerase chain reaction confirmation of influenza, which was performed for research purposes only. ^dSelf-rated health on a scale of 0 (worst) to 100 (best), analyzed as a continuous variable.