Patients hospitalized for asthma exacerbation often receive antibiotic therapy but this provides no additional benefit, according to results of a large retrospective analysis in JAMA Internal Medicine.

“In a prior observational study, we found that although guidelines do not recommend antibiotics for patients hospitalized with an asthma exacerbation unless [there are] clear signs of infection, 41 percent of patients receive antibiotics on day 1 of hospitalization,” first author Dr. Mihaela Stefan, from University of Massachusetts Medical School-Baystate in Springfield, told Reuters Health.

“The data supporting the lack of efficacy of antibiotics comes from a limited number of studies and most assessed symptoms or spirometry data and not outcomes such as length of stay, mortality, readmission. We wanted to determine the association of antibiotic prescribing with outcomes in real-world, in a large cohort of patients hospitalized,” she said by email.

In the cohort of 19,811 adults hospitalized for asthma exacerbation and treated with systemic corticosteroids in 542 hospitals between 2015 and 2016, a total of 8,788 (44 percent) were started on an antibiotic during the first two days of their hospital stay.

These patients were older (median age, 48 vs 45 years), more likely to be white (49 vs 41 percent) and smokers (7 vs 5 percent), and they had a higher number of comorbidities (eg, congestive heart failure, 6 vs 6 percent) than their peers who did not start an antibiotic.

In a propensity score-matched analysis, antibiotic therapy was not associated with better patient outcomes (odds ratio for risk of treatment failure, 0.95; 95 percent CI, 0.82–1.11). It was, however, associated with a 29 percent longer length of hospital stay, higher hospital costs (median, $4,776 vs $3,641) and, in a sensitivity analysis, increased risk of antibiotic-related diarrhea (OR 2.6; 95 percent CI 1.7–3.9). There was no between-group difference in readmission rates at 30 days.

“These findings are novel, reflect the experience of unselected patients cared for in routine settings, and lend strong support to current guidelines that recommend against the use of antibiotics in the absence of concomitant infection. In addition, the findings highlight the need for future research to improve antimicrobial stewardship in the setting of asthma,” Dr. Stefan and colleagues write in their paper.

In particular, they say research is needed to develop and test “de-implementation strategies” to reduce inappropriate antibiotic prescribing for patients hospitalized for asthma.