Antibiotic Prescribing for Cellulitis by Australian Early Career GPs: A Longitudinal Analysis

Background Cellulitis is a common bacterial skin infection usually requiring antibiotic treatment. Accurate diagnosis and management are crucial for patient prognosis and antibiotic stewardship. Phenoxymethylpenicillin is usually the recommended first‐line antibiotic for suspected streptococcal nonpurulent cellulitis. This study investigated antibiotic prescribing patterns and temporal trends for new diagnoses of cellulitis by Australian general practice registrars (speciality trainees in general practice [family medicine]). Methods Analyses of the Registrar Clinical Encounters in Training (ReCEnT) study utilised registrars’ 2010–2021 consultation data involving new diagnoses of cellulitis. The proportion of consultations involving the prescription of antibiotics was calculated. Univariable and multivariable logistic regression examined longitudinal changes in the prescription of the two most prescribed antibiotics (cefalexin vs. flucloxacillin/dicloxacillin), adjusted for patient, registrar, practice and consultation factors. Results A total of 3852 registrars provided data. Of 2708 new diagnoses of cellulitis, flucloxacillin/dicloxacillin was most commonly prescribed ( n = 1209; 43.6% [95% CI: 41.8, 45.5), followed by cefalexin ( n = 1191; 43.0% [95% CI: 41.1, 44.9]). Phenoxymethylpenicillin was prescribed in 0.6% of cases [95% CI: 0.3, 0.9]. Cephalexin prescription relative to flucloxacillin/dicloxacillin did not change over the 12‐year period (OR 0.99 per year [95% CI: 0.96, 1.03]). Prescription of cefalexin, compared to flucloxacillin/dicloxacillin, was associated with (compared to the age group 25–44 years) ages less than 5 years (OR 2.75 [95% CI: 1.70, 4.43], 5–14 (OR 2.51 [95% CI: 1.63, 3.89]) and 65 years and older (OR 1.51 [95% CI: 1.15, 1.99]). Cefalexin prescription was less likely when registrars sought in‐consultation information from ‘Therapeutic Guidelines (Antibiotic)’ guidelines (OR 0.58 [95% CI: 0.43, 0.80]), supervisors (OR 0.69 [95% CI: 0.51, 0.94]) or other sources (OR 0.64 [95% CI: 0.43, 0.96]). Conclusions Phenoxymethylpenicillin was prescribed in only 0.6% of presentations, whereas cefalexin and flucloxacillin/dicloxacillin accounted for over 86% of prescriptions. This may reflect a lack of guideline specificity regarding first‐line treatment options and/or registrars’ aetiological diagnostic uncertainty. Prescribing patterns remained relatively stable over time.