Validation of Coding Algorithms for the Identification of Herpes Zoster among Children.

TitleValidation of Coding Algorithms for the Identification of Herpes Zoster among Children.
Publication TypeJournal Article
Year of Publication2021
AuthorsRutstein BH, Gmuca S, Gerber JS, Lim T, Argraves M, Ogdie A
JournalPharmacoepidemiol Drug Saf
Date Published2021 May 07

PURPOSE: To examine the validity of International Classification of Diseases, 10th Revision, (ICD-10) code-based algorithms for herpes zoster (HZ) in the electronic medical record (EMR) of a large, integrated pediatric healthcare network and to examine baseline demographics and chronic comorbidities associated with HZ in a representative pediatric population.

METHODS: We reviewed the electronic charts of all patients with a single ICD-10 for HZ (B02.xx) as their primary or secondary diagnosis in the EMR of the Children's Hospital of Philadelphia (CHOP) healthcare network from January 2010 - March 2019. The positive predictive value (PPV) for a single code for HZ was calculated and alternative algorithms were examined to determine which method resulted in the highest PPV.

RESULTS: The PPV for a single ICD-10 code was 91.7% (95% CI 80.8-95.4) for definitive and/or probable cases of HZ and 63.9% (95% CI 53.4-75.5%) for definitive cases alone. Adding a prescription for an antiviral did not improve the PPV. However, adding a new code for rash entered within 1 week of the HZ code increased the PPV to 100% for definitive and/or probable cases but with substantial loss of sensitivity. A high proportion of children with HZ who required inpatient hospitalization had chronic disease (70%) and were on systemic immunomodulatory therapy (50%).

CONCLUSIONS: HZ can be identified with a high PPV in electronic medical records of children using ICD-10 code alone. These findings lay the foundation for future pharmacoepidemiologic research to better understand risk factors for HZ infection.

Alternate JournalPharmacoepidemiol Drug Saf
PubMed ID33960541