Using Z Codes to Document Social Risk Factors in the Electronic Health Record: A Scoping Review.

Introduction: Individual-level social risk factors have a significant impact on health. Social risks can be documented in the electronic health record using ICD-10 diagnosis codes (the "Z codes"). This study aims to summarize the literature on using Z codes to document social risks.

Methods: A scoping review was conducted using the PubMed, Medline, CINAHL, and Web of Science databases for papers published before June 2024. Studies were included if they were published in English in peer-reviewed journals and reported a Z code utilization rate with data from the United States.

Results: Thirty-two articles were included in the review. In studies based on patient-level data, patient counts ranged from 558 patients to 204 million, and the Z code utilization rate ranged from 0.4% to 17.6%, with a median of 1.2%. In studies that examined encounter-level data, sample sizes ranged from 19,000 to 2.1 billion encounters, and the Z code utilization rate ranged from 0.1% to 3.7%, with a median of 1.4%. The most reported Z codes were Z59 (housing and economic circumstances), Z63 (primary support group), and Z62 (upbringing). Patients with Z codes were more likely to be younger, male, non-White, seeking care in an urban teaching facility, and have higher health care costs and utilizations.

Discussion: The use of Z codes to document social risks is low. However, the research interest in Z codes is growing, and a better understanding of Z code use is beneficial for developing strategies to increase social risk documentation, with the goal of improving health outcomes.