A study found that hospital providers who prescribe unnecessarily high rates of antibiotics are likely to continue doing so over time.
The unnecessary over-prescription of antibiotics contributes to global health crises like Clostridioides difficile (C diff) infection and antimicrobial resistance, as dangerous pathogens learn to mutate to resist treatment. Prescribing antibiotics only as needed is a crucial tenet of antimicrobial stewardship.
There is a need for provider-specific prescribing metrics to ensure hospitals are curbing antibiotic use. One study, presented at the Society for Healthcare Epidemiology of America Conference 2022 (SHEA), aimed to improve the credibility of a risk-adjusted antibiotic prescribing metric for Hospital Medicine Service (HMS) providers. The investigators sought to determine whether providers who initially prescribe excessive antibiotics continue to do so.
The research team, led by study lead author and presenter Udodirim Onwubiko, MBBS, MPH, compiled administration and billing data at 4 acute care hospitals (1571 beds). For each billed patient day from January 2020-June 2021, the investigators calculated days of therapy (DOT) ordered by individual prescribers for 3 antibiotic groupings: broad spectrum-hospital onset (BS-HO), broad spectrum-community onset (BS-CO) or anti-MRSA.
The investigators used mixed models adjusted for patient-mix characteristics to calculate serial bimonthly provider-specific observed-to-expected ratios (OER). Utilizing binomial generalized estimating equations, they determined whether a high prescribing rate (defined as an OER ≥1.25, or 25% higher prescribing rate than predicted) for an individual provider remained consistently high from one bimonthly period to the next.
The study included a total of 975 bimonthly periods from 136 hospitals, 58% of which contributed data for the entire 18-month period. Average Q1 and Q3 OERs were similar across hospitals: 0.94 for BS-HO antibiotic prescriptions, 0.99 for BS-CO antibiotics, and 0.95 for anti-MRSA antibiotics. Examining individual prescriber levels, 21-31% of bimonthly observed-to-expected antibiotic prescription rates were categorized as high. At most hospitals, a provider with a high OER for either BS-HO or BS-CO antibiotics in any bimonthly period were more likely to have a high OER in the following period.
Hospitals with a higher than anticipated bimonthly rate of antibiotic prescriptions were likely to continue these high prescribing rates in the following bimonthly period. This was especially true for BS-HO antibiotics. These findings have major implications for antibiotic stewardship efforts, as they suggest that providers are not overprescribing antibiotics on a case-by-case basis, but are uniformly and continuously overprescribing. The study authors recommended future research into prescription rates of other antibiotic groupings.
The study, “Do Hospitalists Prescribing High (Risk-adjusted) Rates of Antibiotics do so Repeatedly?” was presented on April 12 during the Society for Healthcare Epidemiology of America Conference 2022 (SHEA).