Prescribing patterns from medical chart abstraction of patients administered lipegfilgrastim: a pilot study in Europe

Purpose: The objective of this pilot study was to explore the feasibility of conducting a drug utilization study of lipegfilgrastim in Europe using medical records and to examine the pattern of lipegfilgrastim on-label and off-label use. Methods: Data on lipegfilgrastim use between September 2014 and April 2017 were abstracted from medical records by two independent medical abstractors. Lipegfilgrastim indication was categorized either as on-label or as one of four types of off-label (I–IV) according to pre-defined criteria. An inter-rater reliability analysis was conducted to measure the degree of abstractor agreement for on-label and off-label use. Results: Information from 46 medical records was abstracted. Lipegfilgrastim use during the first chemotherapy treatment cycle was mostly indicated for prevention of neutropenia (82.6% of patients). On-label use was documented in 42 patients (91.3%), while off-label use was documented in two patients (4.3%); all events of off-label use were attributed to use with non-cytotoxic drugs. The remaining two patients (4.3%) had missing data. Overall agreement between the abstractors was high (91.6%). For three types (Types I–III) of off-label use, the kappa values suggested a perfect agreement (κ = 1). For Type IV off-label use (use in patients treated with non-cytotoxic drugs), κ = 0, suggesting a poor agreement. Conclusions: KEY POINTS: Findings from this pilot study confirm the feasibility and availability of medical records and the use of pharmacists as abstractors to assess on-label and off-label use of lipegfilgrastim in routine clinical practice. Lipegfilgrastim was mainly prescribed according to the approved indications, and the proportion of off-label use was low. The high inter-rater agreement between the two abstractors suggests that one abstractor is sufficient for conducting chart abstraction of on- and off-label use. Additional data abstraction sources other than pharmacists will need to be identified to improve response rate and center recruitment. Findings from this pilot study are important for the successful planning and execution of subsequent drug utilization studies.