Gastroschisis: Is the Combination of Diagnosis and Procedure Code Sufficient for Case-Confirmation?

Timely, accurate reporting is essential for population-based surveillance of birth defects. Searching specific diagnosis codes in hospital discharge data is standard practice for identifying potential cases; however, it lacks the confidence obtained through chart review for case confirmation. While inarguably valuable, case confirmation is time-consuming. This study aimed to assess the value of diagnosis and procedure codes for case confirmation using various combinations of ICD-10-CM/PCS codes (henceforth termed ICD-10).

For birth years 2021 and 2022, Arizona used two databases for case-finding and case confirmation analysis. The authors used the Arizona Hospital Discharge Database to identify potential gastroschisis cases, querying ICD-10 codes Q793, 0WQF0ZZ, and 0WUF0JZ. Arizona's Birth Defect Registry (BDR) database represents our gold standard for true cases, as they are all confirmed via medical chart review. Arizona used standard epidemiology practices for comparing the data, focusing on positive predictive value (PPV) to compare two cohorts: Diagnosis Only and Diagnosis + Procedure.

The traditional query of diagnosis code only yielded a PPV of 68.8%, whereas the new query using both diagnosis code and 1 or 2 procedure codes produced a PPV of 100.0%.

The combination of codes produced results with more confidence than just the typical case-finding process, and could feasibly be used to confirm cases without chart reviews.

Using the diagnosis code and procedure code simultaneously enables a more efficient gastroschisis case-confirmation process and potentially improves overall surveillance.