# Canadian adaptive platform trial of treatments for COVID in community settings (CanTreatCOVID): recruitment strategies of a decentralized, national randomized controlled trial for acute SARS-CoV-2

## TL;DR

This paper explores how digital and traditional recruitment methods were used in a national Canadian trial for COVID-19 treatments, showing that digital channels were more effective.

## Contribution

The study provides insights into effective recruitment strategies for decentralized clinical trials using a mix of digital and traditional methods.

## Key findings

- Digital recruitment channels had higher odds of recruitment compared to traditional channels (adjusted OR = 2.78).
- Family, friends, or colleagues were the most frequently reported referral source (20%).
- Recruitment channels varied significantly by province (χ2(5) = 81.30, p < 0.001).

## Abstract

Recruitment remains a challenge in clinical trials. This study describes the use of digital and traditional recruitment channels in a national, community-based adaptive platform trial for COVID-19 in Canada.

Self-reported recruitment sources were collected from participants of a remote, national adaptive platform trial of COVID-19 treatments conducted across six Canadian provinces using a secure web-based application. Recruitment channels were analyzed using descriptive statistics, chi-square tests, and logistic regression to explore associations with province.

From January 2023 to September 2024, 1,515 participants completed the pre-screening process, and 720 were randomized. Of them, 416 were recruited through traditional channels, 303 through digital channels, and one through an undetermined source. Recruitment channels varied by province (χ2(5) = 81.30, p < 0.001; Cramér’s V = 0.34), and digital channels were associated with higher odds of recruitment compared with traditional channels (adjusted OR = 2.78, 95% CI 2.20–3.52). The most frequently reported referral source was ‘family, friends, or colleagues’ (20%), followed by provincial government websites and health lines (16.25%), online channels (10.56%), and public communications (9.86%).

Combining traditional and digital recruitment methods supports recruitment. Trials can raise awareness of the study by leveraging both digital and traditional channels and can move information to action through trusted social groups and institutions. Further research is needed to evaluate the cost-effectiveness, reach, and demographic differences across platforms, informing recruitment strategies in future decentralized and adaptive trials beyond COVID-19.

https://clinicaltrials.gov/study/NCT05614349, Identifier NCT05614349.