National patterns in the use of International Statistical Classification of Diseases and Health Related Problems,...

In the tenth revision of the International Statistical Classification of Disease and Health Related Problems (ICD-10), Z codes were added to improve documentation and understanding of health-related social needs. We estimated national Z code use in the ambulatory surgery setting from 2016 to 2019.

Using the Nationwide Ambulatory Surgery Sample (NASS), we identified encounters for ambulatory surgery with an ICD-10 code between Z55.0 and Z65.9. Data were stratified by Z code domains from the Centers for Medicare and Medicaid Services (CMS).

This analysis of 41,827 ambulatory surgery encounters with documented Z codes found that the most documented determinants of health related to multiparity or unwanted pregnancy, homelessness, and incarceration. There was a 16.1% increase in the use of Z codes from 2016 to 2019.

Rates of Z code use in the ambulatory surgery setting are increasing with current documentation serving as a specific but not sensitive measure of socioeconomic need.