Medicalising diagnoses and treatment preferences: a retrospective cohort study of throat-related consultations in electronic primary care records

BACKGROUND: Rather than first diagnosing and then deciding on treatment, general practitioners (GP) may intuitively decide on treatment and justify this through choice of diagnosis.

AIM: To investigate the relationship between choice of a medicalising diagnosis and antibiotic treatment for throat-related consultations.

DESIGN & SETTING: A retrospective cohort study in a large database of UK electronic primary care records between 1st January 2010 and 1st January 2020.

METHOD: We included all first throat-related consultations, categorised as either pharyngitis/tonsillitis or sore throat. The outcome was any antibiotic prescription on the consultation date.We estimated GP-level random effects on prescribing and on diagnosis in a series of mixed-effects regression models, including age, sex, weekday, month and clinician characteristics as fixed effects. We grouped GPs into quintiles by antibiotic prescribing propensity and described the proportion of patients they diagnosed pharyngitis/tonsillitis or sore throat in each quintile.

RESULTS: Our analysis dataset included 393,590 throat-related consultations with 6,881 staff. Diagnosis of pharyngitis/tonsillitis was strongly associated with antibiotic prescribing (adjusted odds ratio 13.41; 95% confidence interval: 12.8-14.04). GP random effect accounted for 18% of variation in prescribing and for 26% of variation in diagnosis. GPs in the lowest quintile of antibiotic prescribing propensity, diagnosed pharyngitis/tonsillitis on 31% of occasions and compared to 55% in the highest.

CONCLUSIONS: There is substantial between GP variation in diagnosis and treatment of throat-related problems. Preference for a medicalising diagnosis is associated with a preference for antibiotics, suggesting there is a common propensity to both diagnose and treat.