Increased antibiotic use correlates with higher risk for hospital admission
The number of antibiotic prescriptions a patient receives may increase that person’s likelihood of being admitted to the hospital, according to a study published in BMC Medicine.
“The clinical effectiveness of frequently prescribing antibiotics for common infections, although widespread in clinical practice, is unproven — and possibly negative,” Tjeerd van Staa, MD, PhD, professor in health e-research at the University of Manchester’s Health eResearch Centre, told Healio. “Further work is needed to establish when antibiotics should be used repeatedly for common infections, such as obtaining cultures before prescribing another antibiotic and better tools to identify patients at higher risk for clinical complications.”
The population-based cohort study of 1.8 million patients used electronic health records from primary care linked to hospital admission records. The study population was composed of patients prescribed a systematic antibiotic with a recent record of certain infection and no history of chronic obstructive pulmonary disease. The researchers examined records from 2000 to 2016, looking for common issues like upper respiratory tract infections, UTIs and ear and chest infections. Long-term conditions like cystic fibrosis and chronic lung disease were omitted.
The researchers broke down their results according to the number of antibiotic prescriptions a patient received in the preceding 3 years. Patients with nine or more antibiotic prescriptions for common infections were 2.26 times more likely to go to the hospital because of another infection in three or more months. Patients with two antibiotic prescriptions were 1.23 times more likely be hospitalized with another infection, while patients with three or four prescription were 1.33 times more likely and patients who had five to eight prescriptions were 1.77 times more likely to be hospitalized.
When comparing the highest to lowest previous exposure quintiles for patients without comorbidity, incidence rate ratios were 1.18 (95% CI, 0.9-1.55) for the first 3 days following antibiotic prescription, 1.44 (95% CI, 1.14-1.81) for days 4 to 30 and 3.22 (95% CI, 2.29-4.53) for 3 to 6 months following a prescription. The highest rates of hospital admission for infection-related complications occurred shortly after the initiation of antibiotics in all prior exposure quintiles.
The findings, coupled with the lack of other evidence on the efficacy of frequent antibiotic use for common infections, highlight the importance of antimicrobial stewardship, van Staa told Healio.
“Stewardship interventions should target these patients with higher use of antibiotics but apparently limited value,” van Staa said. “This could include clinical audits of those patients — why are they getting so many antibiotics? — as well as interventions that focus on reducing this repeated use.”
For example, improving patients’ knowledge about the risks of frequent antibiotic use and potential lack of efficacy could be important, he said.
One of the study’s major limitations, according to van Staa, was that the comparison groups — patients with different histories of antibiotic use — were not randomly assigned. He also noted that unmeasured confounding, such as patients with more antibiotic use being immunocompromised and, therefore, likely to be admitted to the hospital regardless of antibiotic use, could not be excluded.
“Clinicians may need better information on which patients are likely to develop clinical complications. Treatment guidelines on common infections may need greater consideration about when to treat or not and what to do with patients who repeatedly return to the office,” van Staa said. “Preserving our current arsenal of very effective antibiotics by better targeting of patients is at least as important, arguably, as developing new antibiotics.” – by Eamon Dreisbach
Disclosure: van Staa reports no relevant financial disclosures.