Comments on “Factors affecting 1-year persistence with vedolizumab for ulcerative colitis: a multicenter, retrospective real-world study”

consideration is the absence of adherence measurement prior to estimating treatment persistence.Persistence was defined as continuation of VDZ without discontinuation for any reason up to 54 weeks, and discontinuations were classified as primary nonresponse, loss of response, adverse events, or other causes based on clinician assessment.No adherence measures were reported.Although the limitations section discusses the retrospective design, lack of dose escalation approval in Japan, clinician-based variability in assessing loss of response, and limited follow-up duration, it does not acknowledge the absence of adherence data as a limitation.This methodological distinction is particularly relevant for VDZ, where real-world implementation may be affected by infusion scheduling, delays, missed visits, and care-pathway constraints, potentially influencing clinical trajectories without necessarily being captured as formal discontinuation.Moreover, the study defines loss of response based on clinician judgment (sustained nonresponse, worsening, or need for rescue medication), which is clinically meaningful but may overlap with non-pharmacologic determinants of perceived effectiveness.Without explicit adherence/implementation assessment, persistence estimates may conflate biological treatment failure with patient-or system-level factors, and predictors of discontinuation (such as tacrolimus use or short disease duration) may partly reflect disease complexity combined with implementation challenges in routine practice.This interpretation should also be considered in light of the Japan-specific regulatory context, where dose escalation was not approved during the study period, because persistence