Objective:
To identify patient factors associated with change in hemoglobin
A1C (A1C) with adjunct pioglitazone therapy in routine clinical
practice.
Methods: This was a retrospective analysis of adult type 2 diabetes
mellitus patients in a health maintenance organization setting
who were newly-initiated on pioglitazone between January 2002
and December 2005. Eligible patients were receiving at least one
other oral antihyperglycemic medication prior to initiating pioglitazone
and maintained a stable dose of pioglitazone for 90 days. Data
on eligible patients’ characteristics, pharmacy purchases, comorbidities,
and A1C measurement 90 days prior to the pioglitazone purchase
date (baseline) and 90 days after achieving a stable dose (follow-up)
were obtained from electronic records. Multivariate regression
modeling was used to assess factors independently associated with:
1) absolute change in A1C, 2) achieving a =1 percentage point
decrease in A1C, and 3) achieving an A1C <7%.
Results: Baseline and follow-up A1Cs were available for 128 patients.
At baseline, mean age was 65 years, 38% were female, mean A1C
was 8.4%, and 74% had an A1C >8%. At follow-up, the mean A1C
change was -1.2 percentage points (interquartile range = -0.4,
-2.1), 59% achieved a =1 unit decrease in A1C, and 44% achieved
an A1C <7%. Independent predictors in all models were baseline
A1C and time (in days) between baseline and follow-up A1C measurements
(p<0.05).
Conclusions: Adjunct pioglitazone therapy in routine clinical
practice was associated with clinically meaningful reductions
in A1C levels. Patients with higher baseline A1C achieved the
greatest absolute reduction in A1C but were less likely to achieve
levels <7%.
