Analysis of the Medication Persistence Rate for and Adherence to Oral 5-Aminosalicylic Acid Preparations in Japanese Patients with Ulcerative Colitis: Study Using a Nationwide Claims Database.

Introduction 5-aminosalicylic acid (5-ASA) is the first-line drug for the treatment of mild-to-moderate ulcerative colitis (UC). Three oral sustained-release formulations are often used. However, no unified view of their actual use in routine medical practice has been presented to date. Methods Using a health insurance claims database, we extracted patients with an initial diagnosis of mild-to-moderate UC during the period from December 1, 2017 to March 31, 2022. For the three types of oral 5-ASA formulation, we calculated and compared descriptive statistics of medication persistence rates (MPR), proportions of days covered (PDC) and adherence proportion (PDC ≥ 80%) in the extracted population. Results An oral 5-ASA formulation was used in combination with a topical preparation (Cohort 1) in 899 patients, and oral 5-ASA was used alone (Cohort 2) in 1829 patients. In Cohort 1, MPR at days 151-180 with concomitant use of topical formulation was significantly higher for the Multi Matrix SystemTM (MMX) formulation (65.2%) compared with that for pH-dependent formulation (51.7%, p < 0.025), while MPR tended to be higher for MMX than for the time-dependent formulation (56.4%, not significant). During days 151-180 after starting the oral formulation, MPR for MMX (66.7% and 65.8%) was higher than for pH-dependent (55.9% and 55.3%) and time-dependent (57.6% and 55.9%) formulations in Cohorts 1 + 2 and 2, respectively. In Cohort 1, there was a significant difference between MMX (68.3%) and pH-dependent (57.1%) formulations, but no significant difference was seen with time-dependent formulations (61.8%). In terms of the proportion with adherence until Day 180, MMX was significantly better than the other formulations. Conclusion The analyses of the three oral 5-ASA formulations suggested that both MPR and medication adherence were better for the MMX formulation than for time-dependent or pH-dependent formulations.