Pharyngitis clinical prediction rules: effect of interobserver agreement: a MetroNet study

Abstract

Objective: Pharyngitis clinical prediction rules improve Group A beta-hemolytic streptococcus (GABHS) diagnosis and decrease unnecessary antibiotic use, yet few studies have addressed clinician variability in assessment of sore throat signs and symptoms.

Study design and setting: We conducted a cross-sectional study in which two clinicians examined each of 200 adult sore throat patients. Each patient had a rapid GABHS antigen test. Clinicians were blinded to each other's assessment and to the rapid antigen result. Interobserver agreement was estimated using a kappa coefficient. Effect of agreement on sensitivity, specificity, and hypothetic rapid antigen testing and antibiotic prescribing was determined for two clinical prediction rules.

Results: We found moderate inter-rater reliability on sore throat history and physical assessments. Clinician agreement was associated with significantly fewer hypothetic rapid antigen tests performed.

Conclusion: Interobserver agreement enhances the utility of pharyngitis clinical prediction rules. Medical school and residency training should focus on correct assessment of history and physical examination components used in GABHS clinical prediction rules. Correct assessment will result in less GABHS testing and antibiotic prescriptions for sore throat patients.