A/B design testing of a clinical trial recruitment website: A pilot study to enhance the enrollment of older adults

Abstract

Introduction: Online tools are increasingly utilized in clinical trial recruitment. A/B testing is an effective technology used in political campaigns and commercial marketing to improve contributions or sales. However, to our knowledge, A/B has not been described in the context of clinical trial recruitment.

Methods: Two A/B testing experiments were implemented on the recruitment website of the Study To Understand Fall Reduction and Vitamin D in You (STURDY), a response-adaptive, two-stage, randomized controlled trial. Commercial A/B platforms randomized web-users to different versions of the trial's website landing page; Experiment 1 included two infographic versions and Experiment 2 included three video versions. We compared web-user engagement metrics between each version and the original landing page. We determined the effect of each version compared to the original landing page on the likelihood of a web-user to (1) request more information about the trial, (2) complete a screening visit, or (3) enroll in the trial.

Results: A total of 2605 and 374 web-users visited the trial's website during Experiment 1 and 2, respectively. Response to the online interest form significantly differed by infographic version in Experiment 1. The number of individuals who engaged with website content and pages significantly differed by video in Experiment 2.

Conclusion: In a pilot study implementing A/B testing of a clinical trial recruitment website, different versions of the website led to differences in web-user engagement and interest in the trial. A/B testing tools offer a promising approach to test the effectiveness of clinical trial recruitment materials and to optimize recruitment campaigns.

Clinical trial registration: This trial is registered at ClinicalTrials.gov. The trial registration number is NCT02166333. The URL is: https://ichgcp.net/clinical-trials-registry/NCT02166333 Trial Registration Number: NCT02166333 Trial Register: ClinicalTrials.gov.

Keywords: A/B testing; Clinical trials; Randomized control trial; Recruitment methods.

Conflict of interest statement

Declaration of Competing Interest

The authors declare that there is no conflicts of interest.

Copyright © 2021 Elsevier Inc. All rights reserved.

Figures

Fig. A1.

Original landing page.

Fig. 1.

Experiment design diagrams. aDigital randomization completed by A/B testing platform. bUser data includes the number of webpage visitors and the number of clicks on the webpage. cThere was only 1 place to access the form on the website. The forms were identical, but unique to each version in order to track response rates. dUser data includes the number of webpage visitors,the bounce rate and the goal conversion rate for each visit.

Fig. 2.

Experiment 1 infographics. Note: Infographics were formatted to grayscale for publication.