Prior Care Experiences Determine Antibiotic Prescribing for Future Acute Respiratory Illness

Patients who visit a clinician with a higher antibiotic prescribing rate are more likely to receive antibiotics for acute respiratory illness (ARI) in the subsequent year, driven largely by patients being more likely to seek care for future ARIs, according to study results published in Clinical Infectious Diseases.

While excessive antibiotic prescribing for ARIs remains high, one driver of this could be a patient’s prior care experience. Patients may attribute clinical improvements to the antibiotics, whether or not the antibiotic was truly effective, reflecting a form of illusionary correlation. Using the novel approach of exploiting the quasi-randomization of patients to clinicians in urgent care centers, researchers examined the association between the clinician’s antibiotic prescribing rate to the patients’ rates of ARI antibiotic receipt as well as their spouses’ rate of antibiotic receipt in the subsequent year.

Using de-identified encounter data from Aetna, a national United States health plan, researchers identified patients <65 years old with an index visit for an ARI to an urgent care center from January 1, 2013 to June 10, 2016. They categorized clinicians within each urgent care center into quartiles based on their ARI antibiotic prescribing rate. The index visit was defined as the first ARI urgent care center visit where the patient had no ARI visits in the preceding 21 days in any setting. The primary outcome was ARI antibiotic receipt per 100 people across all outpatient settings in the subsequent year after a patient’s index ARI visit. The subsequent year was defined as days 22 to 385 after the index visit, with the 12 months broken down into four 3-month periods (months 1-3, 4-6, 7-9, and 10-12).

To focus on oral systemic antibiotics, researchers excluded topical, ophthalmic, or otic antibiotics. They categorized broad-spectrum antibiotics as macrolides (excluding erythromycin), fluoroquinolones, and non-first-generation cephalosporins. A secondary outcome was receipt of broad-spectrum antibiotics for an ARI in the subsequent year.

There were a total of 232,256 index ARI urgent care visits with 9577 clinicians to 736 urgent care centers. Urgent care centers had a median of 8 clinicians (range, 4-201). Across the 4 quartiles of clinician antibiotic prescribing, patients had similar demographics and similar predicted probability of receiving an antibiotic based only on patient characteristics. There was a large variation in antibiotic prescribing between providers within the same center: prescribers in the 1st quartile (low prescribers) had an antibiotic prescribing rate of 42.1% while patients treated by prescribers in the 4th quartile (high prescribers) had a rate of 80.2%.

In the year after the index ARI visit, patients seen by high prescribers received 3.0 more fills per 100 people (a 14.6% difference; P <.001) compared with those seen by low prescribers. Patients treated by high prescribers also received 19.4% more ARI broad-spectrum antibiotics in the subsequent year vs low prescribers’ patients (1.9 more fills per 100 people; P <.001).

There were 27,770 spouses of patients with an index visit. Compared with spouses of patients seen by a low prescriber, spouses of patients seen by a high prescriber also had a higher rate of ARI antibiotics in the subsequent year (+3.5 fills per 100 patients; 95% CI, 1.6-5.4; P <.001).

The increased rate of antibiotic receipt in the subsequent year was largely driven by patients being more likely to seek care for future ARIs (+5.6 ARI visits per 100 patients, P <.001), rather than a higher antibiotic prescribing rate during those subsequent ARI visits based on several secondary analyses. For instance, the percent difference in antibiotic fills per 100 among patients seen by high vs low prescribers was similar across the four 3-month periods in the subsequent year. In addition, when researchers stratified patients by whether they received an antibiotic at the index visit, those who were not prescribed antibiotics at the index ARI visit had a similar likelihood of receiving antibiotics in the subsequent year (16.1% in quartile 1 vs 16.5% in quartile 4). Furthermore, in a falsification test, no association was observed between the clinician’s prescribing quartile and a patient’s future receipt of a preventive health visit.

Since the analysis used administrative data, researchers were unable to assess illness severity. In addition, results may differ for other populations, since data used here was comprised of people with private insurance in the United States.

The findings of this study could “be used in future clinician educational efforts by illustrating another negative consequence of inappropriate antibiotic prescribing,” concluded the researchers.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Shi Z, Barnett ML, Jena AB, Ray KN, Fox KP, Mehrotra A. Association of a clinician’s antibiotic prescribing rate with patients’ future likelihood of seeking care and receipt of antibiotics [published online August 10, 2020]. Clin Infect Dis. doi:10.1093/cid/ciaa1173