Presentation (CTI)

OBJECTIVES: Examining treatment patterns for injectable drugs can be challenging in observational studies, particularly with regard to estimating duration of use and discontinuation. Further, these products may be identified in real-world data sources through multiple claim types, namely pharmacy and procedure claims, that require different approaches (days supply, fill intervals) to evaluating treatment patterns. This study aimed to assess the consistency between days supply and fill intervals in pharmacy and procedure claims for selected injectable products to provide insight about imputation methods for duration of injectable medication use.
METHODS: This retrospective study assessed vedolizumab and tocilizumab utilization patterns using the Komodo Research Dataset during January 1, 2016 through June 30, 2024. Adult patients with at least two treatment exposures on different dates within the 12 months of continuous enrollment in medical and drug insurance plans required since the initial injection date were included.
RESULTS: Totals of 59,117 vedolizumab and 34,479 tocilizumab patients were identified. Of these patients, respectively 13.0% and 12.2% of vedolizumab and tocilizumab patients had injections recorded in both outpatient pharmacy and medical procedure claims over time. For vedolizumab, the median time between two consecutive prescription fills was 53 days, and the median time between two consecutive professional administrations was 56 days, whereas the median days supply from pharmacy claims was 30 days. For tocilizumab, both intervals and the median days supply from pharmacy claims were all 28 days.
CONCLUSIONS: To estimate duration of injectable drug use, assessments based on multiple claims types are strongly recommended in order to comprehensively capture exposures. Concordance between claim intervals and days supply varies by injectable products. Future studies focusing on injectable medications should optimize exposed time definitions by exploring distribution of claim type and frequency of records in advance of the full-scale drug utilization evaluations.