BACKGROUND:

The Infectious Disease Society of America recommends pneumococcal urinary antigen testing (UAT) when identifying pneumococcal infection would allow for antibiotic de-escalation. However, the frequencies of UAT and subsequent antibiotic de-escalation are unknown. METHODS:

We conducted a retrospective cohort study of adult patients admitted with community-acquired or healthcare-associated pneumonia to 170 US hospitals in the Premier database from 2010-2015, to describe variation in UAT use, associations of UAT results with antibiotic de-escalation, and associations of de-escalation with outcomes. RESULTS:

Among 159,894 eligible admissions, 24,757 (15.5%) included UAT performed (18.4% of ICU and 15.3% of non-ICU patients). Among hospitals with ≥100 eligible patients, UAT testing proportions ranged from 0%-69%. Compared to patients with negative UAT, 7.2% with positive UAT more often had a positive S. pneumoniae culture (25.4% vs. 1.9%, p<0.001) and less often had resistant bacteria (5.2% vs. 6.8%, p<0.05). Of patients initially treated with broad-spectrum antibiotics, most were still receiving broad-spectrum therapy 3 days later, but UAT-positive patients more often had coverage narrowed (38.4% vs. 17.0% UAT-negative and 14.6% untested patients, p<0.001). Hospital rate of UAT was strongly correlated with de-escalation following a positive test. Only 3 patients de-escalated after positive UAT were subsequently admitted to ICU. CONCLUSIONS AND RELEVANCE:

UAT is not ordered routinely in pneumonia, even in ICU. A positive UAT was associated with less frequent resistant organisms, but usually did not lead to antibiotic de-escalation. Increasing UAT and narrowing therapy after a positive UAT are opportunities for improved antimicrobial stewardship.