Social Needs Identified by Diagnostic Codes in Privately Insured U.S. Adults

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.

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.

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.

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.