Assessing the reliability of pediatric emergency medicine billing code assignment for future consideration as a proxy workload measure

OBJECTIVES: Prediction of pediatric emergency department (PED) workload can allow for optimized allocation of resources to improve patient care and reduce physician burnout. A measure of PED workload is thus required, but to date no variable has been consistently used or could be validated against for this purpose. Billing codes, a variable assigned by physicians to reflect the complexity of medical decision making, have the potential to be a proxy measure of PED workload but must be assessed for reliability. In this study, we investigated how reliably billing codes are assigned by PED physicians, and factors that affect the inter-rater reliability of billing code assignment. METHODS: A retrospective cross-sectional study was completed to determine the reliability of billing code assigned by physicians (n = 150) at a quaternary-level PED between January 2018 and December 2018. Clinical visit information was extracted from health records and presented to a billing auditor, who independently assigned a billing code–considered as the criterion standard. Inter-rater reliability was calculated to assess agreement between the physician-assigned versus billing auditor-assigned billing codes. Unadjusted and adjusted logistic regression models were used to assess the association between covariables of interest and inter-rater reliability. RESULTS: Overall, we found substantial inter-rater reliability (AC(2) 0.72 [95% CI 0.64–0.8]) between the billing codes assigned by physicians compared to those assigned by the billing auditor. Adjusted logistic regression models controlling for Pediatric Canadian Triage and Acuity scores, disposition, and time of day suggest that clinical trainee involvement is significantly associated with increased inter-rater reliability. CONCLUSIONS: Our work identified that there is substantial agreement between PED physician and a billing auditor assigned billing codes, and thus are reliably assigned by PED physicians. This is a crucial step in validating billing codes as a potential proxy measure of pediatric emergency physician workload.