Abstract and Introduction
Abstract
Background: 5-aminosalicylates (5-ASA) are widely used in Crohn's disease (CD) despite guidelines advising otherwise. We aimed to assess in nationwide study the outcomes of first-line 5-ASA maintenance therapy (5-ASA-MT) compared with no maintenance treatment (no-MT) in patients with newly diagnosed CD.
Methods: We utilised data from the epi-IIRN cohort, including all patients with CD diagnosed in Israel between 2005 and 2020. Propensity score (PS) matching was utilised to compare outcomes in the 5-ASA-MT versus no-MT groups.
Results: Of the 19,264 patients diagnosed with CD, 8610 (45%) fulfilled the eligibility criteria (3027 [16%] received 5-ASA-MT and 5583 [29%] received no-MT). Both strategies declined over the years; 5-ASA-MT from 21% of CD patients diagnosed in 2005 to 11% in 2019 (p < 0.001) and no-MT from 36% to 23% (p < 0.001). The probability of maintaining therapy at 1, 3 and 5 years from diagnosis: 5-ASA-MT—78%, 57% and 47% and no-MT—76%, 49% and 38% respectively (p < 0.001). PS analysis successfully matched 1993 pairs of treated and untreated patients and demonstrated comparable outcomes of time to: biologic (p = 0.2), steroid dependency (p = 0.9), hospitalisation (p = 0.5) and CD-related surgery (p = 0.1). Rates of acute kidney injury (5.2% vs. 3.3%; p < 0.001) and pancreatitis (2.4% vs. 1.8%; p = 0.03) were higher in the 5-ASA-MT group compared with the no-MT group but after PS matching the rates of adverse events were similar.
Conclusion: First-line 5-ASA monotherapy was not superior to no-MT but associated with a slightly higher rates of adverse events, while both strategies have declined over the years. These findings suggest that a subset of patients with mild CD may be offered a watchful waiting approach.
Introduction
A subset of patients with Crohn's disease (CD) may have mild and localised disease with an indolent course. Although this group represents 20%–45% of all CD patients,[1–3] they are most often excluded from clinical trials.[4] In these mild, localised cases, clinicians may choose a watchful waiting approach following induction treatment[5–7] or maintenance with conventional therapies.[8]
Although current guidelines advocate against it,[9,10] 5-aminosalicylates (5-ASA) agents are widely used in clinical practice for the maintenance of remission in patients with CD.[11,12] Cochrane reviews suggested no benefit for 5-ASA over placebo and concluded that additional trials on the matter may not be justified.[13,14] However, most of the included RCTs were limited by a relatively small sample size, lack of long-term follow-up, and were prone to selection bias. Several real-world and population-based studies showed that many patients with CD treated with 5-ASA follow an indolent course.[7,11,15–17] However, whether the mild course reflected the treatment effect or merely the natural history of a mild CD remains largely unknown.
Therefore, in this nationwide study, we aimed to compare disease outcomes of patients with newly diagnosed mild CD on first-line 5-ASA maintenance treatment (MT) versus no-MT.
Aliment Pharmacol Ther. 2023;57(9):1004-1013. © 2023 Blackwell Publishing
