Social needs identified by diagnostic codes in privately insured U.S. adults

Introduction: The relationships between healthcare use and social needs are not fully understood. In 2015, International Classification of Diseases, Tenth Revision coding introduced voluntary Z codes for social needs‒related healthcare encounters. This study evaluated early national patterns of Z codes in privately insured adults.

Methods: In 2021, the authors conducted a case-control analysis of national commercial health payer claims from 2016 to 2019. Among adults with ≥6 months of continuous enrollment and ≥1 medical claims, patients with any assigned Z codes were defined as cases. Controls were selected through stratified random sampling. Z codes were organized under 3 categories: socioeconomic, community/social, and environmental.

Results: Of 29.5 million adults, 521,334 patients (1.8%) had any assigned Z codes. Among all the Z codes, 53.5% identified community/social issues, 30.3% identified environmental issues, and 16.2% identified socioeconomic issues. Among socioeconomic Z codes, housing needs were frequently identified, but needs for food, utility bills, and transportation were very rarely identified. In multivariable regression analysis, females had higher odds of Z code assignment than males. Depression and chronic pulmonary disease were the 2 common comorbidities (≥5% prevalence in cases and controls) that were highly associated with Z code assignment. Less common comorbidities strongly associated with Z code assignment were drug abuse, alcohol abuse, psychoses, and AIDS/HIV.

Conclusions: In this national study of privately insured patients, many Z codes identified healthcare encounters caused by social stressors, whereas few identified food- or transportation-related causes. Depression and chronic pulmonary disease were highly associated with Z code assignment.