Analyzing Adherence to Prenatal Supplement: Does Pill Count Measure Up?
Abstract
Objective. To determine if adherence as measured by pill count would show a significant
association with serum-based measures of adherence. Methods. Data were obtained from
a prenatal vitamin D supplementation trial where subjects were stratified by race
and randomized into three dosing groups: 400 (control), 2000, or 4000 IU vitamin D-3/day.
One measurement of adherence was obtained via pill counts remaining compared to a
novel definition for adherence using serum 25-hydroxy-vitamin D (25-OH-D) levels (absolute
change in 25(OH) D over the study period and the subject's steady-state variation
in their 25(OH) D levels). A multivariate logistic regression model examined whether
mean percent adherence by pill count was significantly associated with the adherence
measure by serum metabolite levels. Results. Subjects' mean percentage of adherence
by pill count was not a significant predictor of adherence by serum metabolite levels.
This finding was robust across a series of sensitivity analyses. Conclusions. Based
on our novel definition of adherence, pill count was not a reliable predictor of adherence
to protocol, and calls into question how adherence is measured in clinical research.
Our findings have implications regarding the determination of efficacy of medications
under study and offer an alternative approach to measuring adherence of long half-life
supplements/medications.
Type
Other articleSubject
vitamin-d deficiencysystemic-lupus-erythematosus
rheumatoid-arthritis
cutaneous synthesis
multiple-sclerosis
plasma
25-hydroxyvitamin-d
serum 25-hydroxyvitamin-d
binding-protein
human-pregnancy
ovarian-cancer
endocrinology & metabolism
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https://hdl.handle.net/10161/4319Published Version (Please cite this version)
10.1155/2010/631971Citation
Appelgren,Kristie E.;Nietert,Paul J.;Hulsey,Thomas C.;Hollis,Bruce W.;Wagner,Carol
L.. 2010. Analyzing Adherence to Prenatal Supplement: Does Pill Count Measure Up?.
International Journal of Endocrinology ( ): 631971-631971.
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