Association of patient, physician and visit characteristics with inappropriate antibiotic prescribing in Japanese primary care: a cross-sectional study.

OBJECTIVE

To assess the prevalence and associated factors of inappropriate antibiotic prescribing in Japanese primary care.

METHODS

This cross-sectional study analysed all antibiotic prescriptions written between 1 October 2022 and 30 September 2023, using an electronic health record database of primary care clinics across Japan. Using a previously developed classification algorithm, we determined whether diagnosis codes occurring on or during the 3 days before the antibiotic prescribing date 'always', 'sometimes' or 'never' justified antibiotic use. We classified antibiotic prescriptions into one of four mutually exclusive categories: 'appropriate' (associated with ≥1 'always' code), 'potentially appropriate' (associated with ≥1 'sometimes' code but no 'always' codes), 'inappropriate' (associated only with 'never' codes) and 'not associated with a recent diagnosis'. A linear probability model examined patient, physician and visit characteristics associated with inappropriate antibiotic prescribing among solo practice clinics.

RESULTS

Analyses included 2 058 021 outpatient antibiotic prescriptions to 1 267 708 patients at 2809 clinics. Among these prescriptions, 176 181 (8.6%) were appropriate, 1 238 549 (60.2%) were potentially appropriate, 348 949 (17.0%) were inappropriate and 294 342 (14.3%) were not associated with a recent diagnosis. Among solo practice clinics, inappropriate prescribing was more likely to patients aged <18 versus ≥65 years (+2.6%; 95% CI +0.3% to +4.9%) or with Charlson Comorbidity Index score ≥2 vs 0 (+2.0%; 95% CI +0.6% to +3.4%), for physicians aged ≥65 versus <45 years (+7.3%; 95% CI +3.6% to +11.0%), for physicians in the highest tertile of antibiotic prescribing volume (+4.9%; 95% CI +3.0% to +6.8%), during telehealth visits (+3.9% vs office visits; 95% CI +0.02% to +7.7%) and during regular hours care versus after hours care (+2.1%; 95% CI +0.7% to +3.5%). These findings were qualitatively unchanged when including both solo and group practice clinics.

CONCLUSIONS

Targeting younger patients, patients with comorbidities, older physicians, physicians with high antibiotic prescribing, telehealth visits and regular hours care may further increase stewardship effectiveness.