Predictors of adherence in the Women's Health Initiative Calcium and Vitamin D Trial.
The authors analyzed data from the Women's Health Initiative (WHI) Calcium and Vitamin D Supplementation Trial (CaD) to learn more about factors affecting adherence to clinical trial study pills (both active and placebo). Most participants (36,282 postmenopausal women aged 50-79 years) enrolled in CaD 1 year after joining either a hormone trial or the dietary modification trial of WHI. The WHI researchers measured adherence to study pills by weighing the amount of remaining pills at an annual study visit; adherence was primarily defined as taking > or = 80% of the pills. The authors in this study examined a number of behavioral, demographic, procedural, and treatment variables for association with study pill adherence. They found that relatively simple procedures (ie, phone contact early in the study [4 weeks post randomization] and direct social contact) later in the trial may improve adherence. Also, at baseline, past pill-use experiences, personal supplement use, and relevant symptoms may be predictive of adherence in a supplement trial.
Brunner
R
R
Department of Family and Community Medicine, University of Nevada School of Medicine, Reno, Nevada, USA.
Dunbar-Jacob
J
J
Leboff
M S
MS
Granek
I
I
Bowen
D
D
Snetselaar
L G
LG
Shumaker
S A
SA
Ockene
J
J
Rosal
M
M
Wactawski-Wende
J
J
Cauley
J
J
Cochrane
B
B
Tinker
L
L
Jackson
R
R
Wang
C Y
CY
Wu
L
L
D000368:Aged; D001294:Attitude to Health; D002136:Calcium, Dietary / Q000008:administration & dosage*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005544:Forecasting; D006801:Humans; D008137:Longitudinal Studies; D055118:Medication Adherence / Q000523:psychology*; D008875:Middle Aged; D017698:Postmenopause; D012307:Risk Factors; D014807:Vitamin D / Q000008:administration & dosage*; D016387:Women's Health
D002136:Calcium, Dietary; D014807:Vitamin D