Three week compared to seven week run-in period length and the assessment of pre-randomization adherence: a study within a trial

Collister, D. et al. (2021) Three week compared to seven week run-in period length and the assessment of pre-randomization adherence: a study within a trial. Contemporary Clinical Trials, 107, 106466. (doi: 10.1016/j.cct.2021.106466) (PMID:34098039)

Abstract

Background/aims: To examine how measuring adherence at 3 weeks by self-report and pill counts compares to measurements at 7 weeks in a pre-randomization run-in period. Methods: Study within a trial of an international parallel group randomized controlled trial (RCT) that compares spironolactone to placebo. Adults receiving dialysis enter an 8-week active run-in period with spironolactone. Adherence was assessed by both self-report and pill counts in a subgroup of participants at both 3 weeks and 7 weeks. Results: 332 participants entered the run-in period of which 166 had complete data. By self-report, 146/166 (94.0%) and 153/166 (92.2%) had at least 80% adherence at 3 and 7 weeks respectively (kappa = 0.27 (95% C.I. 0.16 to 0.38). By pill counts, the mean (SD) adherence was 96.5% (16.1%) and 92.4% (18.2%) at 3 and 7 weeks respectively (r = 0.32) with a mean (SD) difference of 3.1% (17.8%) and a 95% limit of agreement from −31.7% to +37.9%. The proportion of adherent participants by self-report and pill counts at 3 weeks agreed in 87.4% of participants (McNemar's p-value 0.58, kappa 0.11, p = 0.02) and at 7 weeks agreed in 92.2% (McNemar's p-value 0.82, kappa 0.47, p < 0.001). Conclusions: Three and seven-week run-in periods and both self-reported and pill count assessments performed similarly. Trial registration: ClinicalTrials.gov Identifier: NCT03020303

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Mark, Professor Patrick

Creator Roles

Mark, P.: Writing – review and editing

• Authors: Collister, D., Mbuagbaw, L., Guyatt, G., Devereaux, P.J., Tennankore, K. K., Reis, G., Sola, L., Xavier, D., Jha, V., Gallagher, M., Dans, A. L., Liu, W., de Zoysa, J., Félix, C., Mark, P. B., Li, Z., Tyrwhitt, J., Wilkinson, J., Sheridan, P., Yuan, F., and Walsh, M.
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
• Journal Name: Contemporary Clinical Trials
• Publisher: Elsevier
• ISSN: 1551-7144
• ISSN (Online): 1559-2030
• Published Online: 05 June 2021
• Copyright Holders: Copyright © 2021 Elsevier Inc.
• First Published: First published in Contemporary Clinical Trials 107: 106466
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher