Association between claims-based setting of diagnosis and treatment initiation among Medicare patients with hepatitis C.

ABSTRACT

OBJECTIVE: To develop a claims-based algorithm to determine the setting of a disease diagnosis. DATA SOURCES AND STUDY SETTING: Medicare enrollment and claims data from 2014 to 2019. STUDY DESIGN: We developed a claims-based algorithm using facility indicators, revenue center codes, and place of service codes to identify settings where HCV diagnosis first appeared. When the first appearance was in a laboratory, we attempted to associate HCV diagnoses with subsequent clinical visits. Face validity was assessed by examining association of claims-based diagnostic settings with treatment initiation. DATA COLLECTION/EXTRACTION METHODS: Patients newly diagnosed with HCV and continuously enrolled in traditional Medicare Parts A, B, and D (12 months before and 6 months after index diagnosis) were included. PRINCIPAL FINDINGS: Among 104,454 patients aged 18-64 and 66,726 aged ≥65, 70.1% and 69%, respectively, were diagnosed in outpatient settings, and 20.2% and 22.7%, respectively in laboratory or unknown settings. Logistic regression revealed significantly lower odds of treatment initiation after diagnosis in emergency departments/urgent cares, hospitals, laboratories, or unclassified settings, than in outpatient visits. CONCLUSIONS: The algorithm identified the setting of HCV diagnosis in most cases, and found significant associations with treatment initiation, suggesting an approach that can be adapted for future claims-based studies.