Validity of International Classification of Diseases Codes for Identifying Alcohol Use and Repeated or...

To describe the validity of alcohol use disorder (AUD), the International Classification of Diseases (ICD) codes for alcohol use and repeated or harm-associated use in pregnancy.

We conducted a retrospective study of pregnancies in individuals who sought care at a medical center from May 2014 to August 2023. We selected all pregnancies with an ICD 9th (ICD-9) or 10th (ICD-10) revision AUD code (ICD-9: 303.9x and 305.x; ICD-10: F10.x and O99.31x) and calculated their positive predictive value (PPV) for capturing alcohol use and repeated or harm-associated use in pregnancy using review of health record as the reference standard. We defined alcohol use as any alcohol consumption during pregnancy and repeated or harm-associated alcohol use as a repeated pattern associated with adverse consequences.

AUD ICD codes were associated with 305 unique pregnancies. The most common AUD ICD code group was 305.x (n=177, 56.4%), followed by F10.x (n=105, 33.4%), O99.31x (n=25, 8.0%), and 303.9x (n=7, 2.2%). The PPV of AUD codes for capturing alcohol use in pregnancy ranged from 10.0% (95% confidence interval [CI], 8.9%-11.2%) for 305.x to 100% (95% CI, 80.9%-99.5%) for O99.31x. The PPV of AUD codes for capturing repeated or harm-associated use in pregnancy ranged from 1.7% (95% CI, 1.6%-1.8%) for 305.x to 28.0% (95% CI, 21.3%-35.9%) for O99.31x.

The PPV of AUD codes for identifying alcohol use and repeated or harm-associated use in pregnancy varies widely across ICD-9 and ICD-10 code groups. These results should be considered when estimating alcohol exposure in pregnancy from administrative data.