Antibiotics Lead to Longer Hospital Stays for Asthma

Costs were higher too, retrospective study found



Treatment with antibiotics during hospitalization for asthma exacerbation was associated with longer hospital stays and higher hospital costs in a retrospective cohort study of nearly 20,000 adult patients.

Mihaela Stefan, MD, PhD, of the University of Massachusetts Medical School in Springfield, and colleagues, found that despite guidelines recommending against routine use of antibiotics for patients hospitalized for asthma exacerbations, 44% of patients in the study cohort received the drugs during the first 2 days of hospitalization.

Compared with patients in the cohort not treated with antibiotics, those prescribed the antimicrobial therapies had higher rates of diarrhea and similar rates of treatment failure, the researchers wrote in the study online in JAMA Internal Medicine.

The findings further highlight the need to reduce inappropriate use of antibiotics among this patient population, the researchers said.

In a 2016 study involving a large national sample, Stefan and colleagues found that about half of patients hospitalized for asthma exacerbations received treatment with antibiotics without a documented indication for antibiotic use.

"The thinking has been that antibiotics have little benefit and may do some harm in patients hospitalized for asthma, but the evidence is limited," Stefan told MedPage Today,adding that in the new study the researchers hypothesized that antibiotic therapy would not be associated with additional benefit.

The team conducted the retrospective cohort study using data collected from 543 hospitals across the U.S. participating in the Premier Inpatient Database, which is an inpatient, enhanced administrative database developed to measure healthcare quality and use.

Participating hospitals were generally small to medium-sized non-teaching hospitals located mostly in cities, and the cohort included 19,811 adults hospitalized for acute asthma exacerbations in 2015 and 2016. All patients were treated with systemic corticosteroids.

Early antibiotic treatment was defined as treatment with an antibiotic initiated during the first 2 days of hospitalization and prescribed for a minimum of 2 days.

The primary outcome was hospital length of stay, and other measures included treatment failure (initiation of mechanical ventilation, transfer to the intensive care unit after hospital day 2, in-hospital mortality, or readmission for asthma) within 30 days of discharge, hospital costs, and antibiotic-related diarrhea.

Multivariable adjustment, propensity score matching, propensity weighting, and instrumental variable analysis were used to assess the association of antibiotic treatment with outcomes.

Of the 19,811 patients, the median (interquartile range [IQR]) age was 46 (34-59), 14,389 (72.6%) were women, 8,771 (44.3%) were white, and Medicare was the primary form of health insurance for 5,120 (25.8%). Antibiotics were prescribed for 8,788 patients (44.4%).

Compared with patients not treated with antibiotics, those who did receive antibiotics were older (median [IQR] age, 48 [36-61] vs 45 [32-57]), more likely to be white (48.6% vs 40.9%) and smokers (6.6% vs 5.3%), and had a higher number of comorbidities (e.g., congestive heart failure, 6.2% vs 5.8%).

Among the other main findings:

• Patients treated with antibiotics had significantly longer hospital stays (median [IQR], 4 [3-5] vs 3 [2-4] days) and a similar rate of treatment failure (5.4% vs 5.8%)

• In propensity score–matched analysis, receipt of antibiotics was associated with a 29% longer hospital stay (length of stay ratio, 1.29; 95% CI, 1.27-1.31) and higher cost of hospitalization (median [IQR] cost, $4,776 [$3,219-$7,373] vs $3,641 [$2,346-$5,942]) but with no difference in the risk of treatment failure (propensity score–matched OR, 0.95; 95% CI, 0.82-1.11)

• Multivariable adjustment, propensity score weighting, and instrumental variable analysis as well as several sensitivity analyses yielded similar results

"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," Stefan and co-authors wrote, adding that the findings also highlight the need for additional research to examine ways to "improve antimicrobial stewardship in the setting of asthma."

Stefan told MedPage Today that finding ways to reduce inappropriate antibiotic use in U.S. hospitals is a public health priority, given their role in promoting antibiotic resistance.

Discontinuation of ineffective, overused, and potentially harmful interventions in medicine -- known as de-implementation -- is emerging as an important area in the field of treatment dissemination, the researchers said.

"Antibiotic treatment in patients with asthma exacerbations is an appropriate practice for de-implementation because it lacks evidence for effectiveness and it may be harmful," the team wrote. Validating known biomarkers, such as the procalcitonin level, for guiding targeted antibiotic therapy is one strategy that could influence clinicians' willingness to refrain from prescribing antibiotics for patients with asthma.

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