(116) Real-World Patterns and Trends of Idarucizumab Use in An Italian Region: A Probabilistic Record-Linkage Approach in The Period 2015-2020

Publication Number: 790

Background: Idarucizumab is a specific reversal agent for dabigatran that was approved in 2015 to restore coagulation. The drug is administered only during inpatient or emergency care: in such settings, its use is poorly captured by most real-world databases.

Objectives: To retrieve individual level information on idarucizumab use from an Italian record-linkage claims database to describe main characteristics of users.

Methods: All person-years (PYs) exposed to dabigatran from January 2015 to December 2020 were calculated from record-linkage claims database, using defined daily doses to estimate the duration of each dispensation. Idarucizumab use was identified from inpatients and/or emergency care, and incidence rate was calculated over PYs of dabigatran use. To identify patients treated with idarucizumab, emergency visits and hospital discharge records were probabilistically linked to dabigatran users, matching date and ward of admission. A further selection was made by a manual assessment of diagnoses and indications of idarucizumab use. The hierarchical criteria used to match each idarucizumab record to a single patient were: (a) date of dabigatran initiation; (b) clinical outcome; (c) diagnosis. Subsequently, each association between idarucizumab administration and hospitalization/emergency visit was ranked as (1) probable, (2) possible, (3) incompatible, (4) non assessable. Linked users were described in terms of indication and followed-up for 30 days to assess mortality.

Results: During the study period, 49,134 PYs of dabigatran use were observed, and 249 administrations of idarucizumab were recorded, corresponding to 5.1 (95% CI: 4.5-5.7) per 1,000 PYs. At the end of the manual assessment 158 (69.0%) administrations were defined as probable (N=103) or possible (N=55). Overall, 230 idarucizumab administrations (92.4%) were linked to at least one patient. Each administration was associated with a median number of 8 hospitalization/emergency visits (interquartile range: 3-14). Hospitalizations/emergency visits referred to 126 patients: 109 (86.5%) with one administration of idarucizumab, 11 (8.7%) with two administrations, 5 (4.0%) with three administrations, and 1 (0.8%) with four. Most of them were men (62.7%), with a median age of 79.1 years. Indications were emergency surgical procedures and life-threatening bleeding in 43 (34.1%) and in 83 (65.9%) patients, respectively. Overall, 30-days mortality was 23.0% (N=29).

Conclusions: This drug utilization study highlights the potential of the Tuscany administrative database in retrieving patient-level information on idarucizumab use and sets the stage for post-marketing surveillance on its safety profile in a real-world setting.