Adherence to study medication and visits: data from the BABY HUG trial.
BACKGROUND
Subject retention and adherence are essential to maintain the power and validity of the Pediatric Hydroxyurea Phase III Clinical Trial (BABY HUG). We designed a study to assess adherence with study medication administration and study visits and to evaluate socioeconomic factors (SES) that may influence these measurements of adherence. These data are important for assessing impact of adherence on BABY HUG trial outcome and defining impact of SES on adherence.


METHODS
Each subject's median study medication (MedAd) and mean visit adherence (VAd) were evaluated. We examined associations of adherence with SES of participating families.


RESULTS
MedAd data were available on 153 of the 191 subjects who started randomized study medication. MedAd was 101.7% of volume prescribed, with 88.9% of subjects taking at least 80% of doses. VAd data were available on 185 of the 191 subjects who started randomized study medication. VAd was 97.3%, with 82.2% of subjects having no missed visits. During dose titration, subjects had on average 12.9% higher medication adherence than subjects who were on a stable dose and had less frequent study visits. MedAd and VAd were not significantly associated with SES.


CONCLUSIONS
Subjects in the BABY HUG trial have had excellent adherence. SES was not associated with adherence, suggesting that SES should not be used as a criterion for enrolment in clinical trials. Additional efforts are needed to maintain medication adherence, particularly when the interval between scheduled visits increases. (ClinicalTrials.gov number, NCT00006400).
Thornburg
Courtney D
CD
Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA. thorn006@mc.duke.edu
Rogers
Zora R
ZR
Jeng
Michael R
MR
Rana
Sohail R
SR
Iyer
Rathi V
RV
Faughnan
Lane
L
Hassen
Leann
L
Marshall
Jennifer
J
McDonald
Roy P
RP
Wang
Winfred C
WC
Huang
Xiangke
X
Rees
Renée C
RC
D000755:Anemia, Sickle Cell / Q000188:drug therapy*; D000986:Antisickling Agents / Q000627:therapeutic use*; D017326:Clinical Trials, Phase III as Topic; D005260:Female; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use*; D007223:Infant; D008297:Male; D010349:Patient Compliance; D010352:Patient Dropouts; D016032:Randomized Controlled Trials as Topic
D000986:Antisickling Agents; D006918:Hydroxyurea