Increase in flu vaccination correlates with decreased antibiotic prescribing
Greater influenza vaccination uptake correlated with state-level reductions in antibiotic use, according to findings published in Open Forum Infectious Diseases.
As a result, increasing influenza vaccination could be “an important intervention” to limit unnecessary antibiotic prescribing, the researchers wrote.
“Since individuals who receive the influenza vaccine are less likely to get influenza, and are less likely to have a severe infection if they do get it, both of which are factors associated with lower rates of antibiotic receipt by individuals, we hypothesized that increasing vaccine rates would protect not only the individuals and reduce their antibiotic use, but by reducing transmission, this would reduce overall prescribing,” Eili Y. Klein, MA, PhD, senior fellow at the Center for Disease Dynamics, Economics and Policy in Washington, D.C., and assistant professor of emergency medicine at Johns Hopkins University School of Medicine, told Healio.
“Given the significant role of antibiotic consumption in contributing to the growing threat of drug resistance, we wanted to investigate whether state-level variations in antibiotic prescribing were independently associated with vaccination coverage,” he continued.
Klein and colleagues performed a retrospective analysis of influenza vaccination coverage and antibiotic prescribing rates from 2010 through 2017 looking only at January through March of each year across the United States. The researchers used data from the IQVIA (formerly IMS Health) Xponent database and the CDC’s FluVaxView to examine the correlation between rates of influenza vaccine coverage and the number of antibiotic prescriptions per 1,000 residents.
The researchers also accounted for certain socioeconomic and structural factors, characteristics that are “important drivers of antibiotic prescribing rates,” according to the study. These factors included statewide poverty rates (to control for standard of living), the number of dialysis centers per 1 million people to (control for general population-level health and health care access) and the number of physicians’ offices per 10,000 people (to control for overall levels of prescribing).
Klein and colleagues also included data on the number of childcare centers per 10,000 children under age 5, “as attendance rates of children are known to be positively correlated with antibiotic use.” Finally, they integrated the difference between mean January and July temperatures to account for seasonal variation and average annual vaccine effectiveness rates to control for the year-to-year effect of vaccination on influenza burden.
According to Klein, the results demonstrated that increased influenza vaccination uptake at the population level was associated with state-level reductions in antibiotic use, even after controlling for socioeconomic, climate-related and health care-related factors. Specifically, for every 10-percentage point increase in the rate of influenza vaccination, antibiotic prescribing rates decreased by 6.5%, Klein said.
The study results showed that this correlation remained true after controlling for socioeconomic differences, access to health care, child care centers, climate, vaccine effectiveness and state-level differences. This was equivalent to 14.2 fewer antibiotic prescriptions per 1,000 people (95% CI, 6-22.4). Additionally, increased vaccination coverage decreased prescribing rates the most in the pediatric population (age 0 to 18 years), by 15.2 prescriptions (95% CI, 9-21.3), or 6%, and the elderly (individuals aged 65 years and older) by 12.8 prescriptions (95% CI, 6.5-19.2), or 5.2%.
According to Klein, there are a myriad of reasons why he and his colleagues observed a relationship between increased vaccination rates and decreased rates of antibiotic prescribing.
“For one, vaccination against influenza can reduce appropriate and inappropriate antibiotic use by reducing the prevalence of influenza-like illness, which is commonly mistreated with antibiotics, and by preventing secondary bacterial infections due to influenza,” Klein said. ”It can also alter patterns of care-seeking behavior and prescribing, which include increasing patient knowledge of the ineffectiveness of antibiotics against viral infections and, in turn, decreasing patient demand for antibiotics.”
It is also possible, according to Klein, that the relationship he and the researchers observed between vaccination coverage and antibiotic prescribing rates is due to some exogenous factor or factors not captured in the study.