Review for 10.1186/1471-230X-12-132 (2012)

Reviewer's report
Title:Association between oral 5-ASA adherence and health care utilization and
costs among patients with ulcerative colitis
Version: 3Date:21 June 2012
Reviewer: Christina Ha
Reviewer's report:
Comments:
While the findings in this study aren’t particularly novel, this does reinforce the
message that adherence to medications may lead to lower medical costs and
hospitalizations/emergency department visits.
Discretionary comments/revisions:
1) With the requirement of at least one corticosteroid prescription within the 12
month post-index period for study enrollment, doesn’t this bias the results
somewhat to a more sick patient population whose disease may not ultimately be
best controlled with therapies usually reserved for patients with mild to moderate
disease? Corticosteroid use implies at least moderate disease activity or disease
that progressed despite being on aminosalicylates. Is it fair to necessarily label
all of these patients as being nonadherent to aminosalicylates if their disease
course may have warranted an escalation in their treatment strategy? Not all
physicians may adopt the approach of layering medications (ie continuing the
5-ASAs) and may opt to change to immunomodulators or biologics instead –
particularly in a group that already required at least one course of corticosteroids
within the first 12 months of the index date. This is mentioned somewhat in the
discussion, however, it raises the question of selection bias towards patients with
more active disease who may not have long-term benefit with 5-ASA
monotherapy.
2) In the results, you state “The total number of all-cause health care visits
across all cost sectors (including inpatient, ER, outpatient, and pharmacy) was
1.13 times higher for adherent patients than for nonadherent patients (IRR =
1.1294; P = 0.0002).” Is that really a useful statement? I wouldn’t necessarily
combine inpatient/ED/outpatient/pharmacy as a single outcome measure.
Non-adherers, if the hypothesis is correct, should have higher inpatient/ED
associated costs than adherers. This is also implied by tables 2 & 3 plus the
subsequent text in the results as adherers lower likelihoods of inpatient
admissions and ED visits with lower associated costs as a result – these findings
are more meaningful and are essentially the crux of the paper.
3) Does UC-related pharmacy prescriptions include all therapies beyond
aminosalicylates or just aminosalicylates? If it includes all UC-related therapies,
can a breakdown be included of the other therapies? It appears that UC-related
therapies is meant to be all-encompassing as in the methods it states that
infliximab, corticosteroids and immunosuppressants were included in the
definition. This would also help serve to address the point in comment #1.
Knowing the breakdown of IMM/steroid and biologic use between adherers and
non-adherers would help nullify the presumption that the non-adherers simply
had greater disease activity.
4) I don’t know if I necessarily agree with the statements in the first paragraph of
the discussion regarding CCI scores – which are a measure of comorbidity, not
UC disease activity: “However, in our study, baseline CCI scores were higher in
the adherent patients, giving credence to the theory that 5-ASA adherence may
decrease utilization and costs despite the higher baseline CCI scores. Patients
therefore were likely to benefit (i.e., have lower medical resource utilization) from
adhering to their medication, regardless of their prior overall medical condition.
This finding helps refute a potential argument that patients with more severe
disease potentially stopped their 5-ASA treatment and therefore had increased
ER visits and hospital admissions.” CCI is not a surrogate for disease activity and
thus does not refute the argument that 5-ASA non-adherers may have had more
severe disease leading to increased ED visits and hospital admissions –
particularly, as mentioned in comment #1, if these patients already required a
course of steroids in the first 12 months of the index date.
Minor revisions:
1) “Total all-cause health care costs, including all cost sectors, were about 29%
higher for nonadherent patients than for adherent patients (mean [95% CI]:
$13,465 [$13,094, $13,835] vs. $17,339 [$17,033, $17,645]).” – I think that the
dollar values were switched by mistake.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests.