Classification of ICD-10-CM Z Codes for Social Determinants of Health From the 2018 Nationwide Readmissions Database Into the Healthy People 2030 Framework

Social determinants of health (SDOH) may influence hospital readmissions. The purpose of this project was to apply provider-assigned International Classification of Diseases-10-CM codes to the Healthy People 2030 SDOH Framework for use in future research focused on hospital readmissions using the 2018 Nationwide Readmissions Database (NRD). We classified all subcodes codes ranging from Z55 to Z65 that were captured within the 2018 NRD. Three researchers independently categorized 80 unique codes into the 5 Healthy People 2030 domains. Inter-rater reliability was 0.664 and the Kappa statistic was 0.54 for initial classifications. The Kappa statistic shows moderate agreement between the raters. After robust discussion, we adjusted 33 classifications to reach classification consensus. Among the 80 codes classified, 8 (10%) were classified into Economic Stability, 6 (7.5%) into Education Access and Quality, 0 into Healthcare Access and Quality, and 13 (16.3%) into Neighborhood and Built Environment, and 53 (66.3%) into Social and Community Context. Classification challenges were due to overlapping and related features of the descriptions that could be applied to more than one domain. Clear coding practice will support researchers, case managers, social workers, and providers in partnering with patients and their family to negotiate a safe evidence-based discharge transition plan.