Review for 10.1186/s12876-024-03455-w (2024)

Title: Adherence to infliximab treatment in patients with immune-mediated inflammatory
diseases from a Referral Center in Brazil: A cohort study
Version: 3 Date: 17 Sep 2024
Reviewer's report:
Overall it is a very well written manuscript that examined adherence to infliximab therapy
in patients at a university hospital referral center, reporting a high adherence rate of 91.04%.
Patients with inflammatory bowel disease had a 39.1% higher risk of non-adherence compared
to others. Most patients achieved disease remission or control, with travel difficulties cited as
the primary reason for missed treatments.
Few edits that I suggest are:
1.The abstract succinctly summarizes the study, but it would be helpful to briefly mention the
sample size and more specific data on adherence barriers like travel difficulties in the abstract
itself.
2. In Introduction:The first paragraph could be condensed to highlight the impact of IMIDs and
the relevance of treatment adherence more clearly. For instance, focus more on the need for
adherence in maintaining remission and managing IMIDs.
Consider moving the paragraph on Brazil's pharmaceutical assistance slightly later, perhaps
when you discuss access to infliximab, to maintain a tighter focus on global context before
shifting to the national level.
3.  The methods section is thorough, but a few areas could use additional clarification:
Sample selection: Clarify why certain patients were excluded (e.g., those transferred from other
centers or those with permanently interrupted treatment). The rationale for exclusion is important
for reproducibility.
Adherence definition: The description of how adherence was calculated is clear, but it may help
to explain briefly why 80% adherence was chosen as the cut-off in the methods section rather
than waiting until the discussion. You mention this is consistent with previous studies, which
could be noted earlier.
4. In Results section:
Sociodemographic data: It’s good to see sociodemographic data well-presented, but a brief
summary of key differences (e.g., those related to age and distance from the referral center) at
the beginning of the results section could help set the stage for more detailed analysis.
The inclusion of a large proportion of patients living far from the referral center adds depth to
the results, but it may be helpful to emphasize this barrier more strongly earlier in the results or
introduction as a known issue affecting treatment adherence in similar studies.
5. The discussion is well-structured, but a clearer link between non-adherence in IBD patients
and specific reasons (like distance or professional restrictions) should be made.
The statement that 32.10% of infusions were not performed on the scheduled date is important,
but you might want to frame this statistic in context—does this reflect a higher non-adherence
rate than expected, or is it typical in similar studies?
The discussion on the cut-off point (80%) and how it influences the results is good, but it would
benefit from more emphasis on how this compares to other real-world studies in developing
countries.
6. You mention some important limitations, but it might help to briefly discuss how the
study’s retrospective design and use of self-reported questionnaires may have led to recall bias,
influencing adherence reporting.
Selection bias: While you mention selection bias due to excluding patients with interrupted
treatment, expanding this to discuss how this impacts generalizability (i.e., does this mean
adherence rates may actually be lower in a more typical population?) could strengthen this
section.
Overall it is excellent paper written well.