Accuracy of identifying pediatric acute bacterial sinusitis diagnoses in outpatient claims data

Purpose Acute bacterial sinusitis is among the most frequent outpatient infections in children and adolescents and is well suited to study in large healthcare utilization databases, but the validity of International Classification of Diseases, 10th Revision (ICD‐10) codes together with antibiotic prescriptions to identify cases of acute bacterial sinusitis has not been established. We aimed to evaluate the validity of ICD‐10 codes combined with antibiotic prescriptions to identify new diagnoses of acute bacterial sinusitis among pediatric patients evaluated in the outpatient setting. Methods Children and adolescents aged 17 years and younger with an outpatient diagnosis of acute sinusitis along with an antibiotic prescription from an ambulatory facility affiliated with the Mass General Brigham health system were identified via a clinical data warehouse. Patients were stratified by age (0–5 years, 6–11 years, and 12–17 years), and 50 cases per age group were randomly sampled. Medical records were independently reviewed by two pediatric infectious diseases physicians to assess for the documentation of a clinician‐defined diagnosis of acute bacterial sinusitis. Positive predictive values (PPVs) and 95% confidence intervals (CIs) were calculated. Results A total of 150 patients were included in the final cohort. Frontal, maxillary, and “unspecified” sinuses accounted for 88% of the diagnoses. The positive predictive value of the algorithm to identify clinician‐defined diagnoses of acute bacterial sinusitis was 92% (95% CI 87%, 95%). The PPVs were consistent across age strata. Conclusions ICD‐10 codes for acute sinusitis, when paired with a same‐day antibiotic prescription, have a high positive predictive value among a cohort of pediatric patients, suggesting that they can be used to study new acute bacterial sinusitis diagnoses with claims.