title: Predictors of adherence in the Women's Health Initiative Calcium and Vitamin D Trial.
abstract: 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.
authors.affiliation: Department of Family and Community Medicine, University of Nevada School of Medicine, Reno, Nevada, USA.
authors.forename: R
authors.initials: R
authors.lastname: Brunner
authors.forename: J
authors.initials: J
authors.lastname: Dunbar-Jacob
authors.forename: M S
authors.initials: MS
authors.lastname: Leboff
authors.forename: I
authors.initials: I
authors.lastname: Granek
authors.forename: D
authors.initials: D
authors.lastname: Bowen
authors.forename: L G
authors.initials: LG
authors.lastname: Snetselaar
authors.forename: S A
authors.initials: SA
authors.lastname: Shumaker
authors.forename: J
authors.initials: J
authors.lastname: Ockene
authors.forename: M
authors.initials: M
authors.lastname: Rosal
authors.forename: J
authors.initials: J
authors.lastname: Wactawski-Wende
authors.forename: J
authors.initials: J
authors.lastname: Cauley
authors.forename: B
authors.initials: B
authors.lastname: Cochrane
authors.forename: L
authors.initials: L
authors.lastname: Tinker
authors.forename: R
authors.initials: R
authors.lastname: Jackson
authors.forename: C Y
authors.initials: CY
authors.lastname: Wang
authors.forename: L
authors.initials: L
authors.lastname: Wu
mesh_terms: 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
chemical_list: D002136:Calcium, Dietary; D014807:Vitamin D