Utilization of Broad- versus Narrow-spectrum Antibiotics for the Treatment of Outpatient Community-acquired Pneumonia

Background: Treatment guidelines for outpatient community-acquired pneumonia (CAP) recommend different antibiotic agents based on presence of comorbidities. Little is known about real-world utilization patterns of narrow- versus broad-spectrum agents for outpatient CAP treatment in non-elderly adults.

Objectives: To characterize patterns of use of guideline-recommended antibiotics for outpatient CAP, overall and within subgroups.

Methods: We used the IBM MarketScan Commercial Database (2008—2019) to identify adults aged 18—64 years diagnosed with outpatient CAP and dispensed a same-day guideline-recommended oral antibiotic agent (3—14 days' supply). We excluded CAP patients at risk for healthcare-associated pneumonia (e.g., immunosuppressive disease, recent hospitalization, recent antibiotic therapy); recent infection; and serious comorbidities (lung disease, cancer, end-stage renal disease). We characterized utilization of narrow- versus broad-spectrum agents, overall and by patient- and provider-level characteristics. In accordance with treatment guidelines, we stratified analyses by otherwise healthy persons versus those with comorbidities (chronic heart, liver, or renal disease; diabetes; perivascular disease) due to differential concern for specific pathogens.

Results: Among 303,348 otherwise healthy CAP patients, 36% received broad-spectrum antibiotics (33% respiratory fluoroquinolone, 3% beta-lactam + macrolide, < 1% beta-lactam + doxycycline) and 64% received narrow-spectrum antibiotics (56% macrolide, 8% doxycycline). Among 24,123 CAP patients with comorbidities, 46% received broad-spectrum antibiotics (42% respiratory fluoroquinolone, 3% beta-lactam + macrolide, 1% beta-lactam + doxycycline) and 54% received narrow-spectrum antibiotics (45% macrolide, 10% doxycycline). From 2008 to 2019, broad-spectrum antibiotic use decreased from 46% to 20% in otherwise healthy patients (average annual percentage change [AAPC], -7.2% [95% CI -8.8%, -5.5%]), and from 57% to 31% in patients with comorbidities (AAPC, -5.4% [95% CI -7.6%, -3.3%]). In subgroup analyses, broad-spectrum antibiotic use varied by rural-urban status, geographic region, provider type, and outpatient setting.

Conclusions: Real-world use of broad-spectrum antibiotics for outpatient CAP declined over time, irrespective of comorbidity status. Non-guideline concordant use of broad-spectrum agents remained common among otherwise healthy patients, particularly in certain subgroups. Antimicrobial stewardship is needed to promote use of narrow-spectrum agents.