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Recruitment in randomized clinical trials: The MeMeMe experience.

Ivan Baldassari¹, Andreina Oliverio¹, Vittorio Krogh¹

¹Department of Research, Epidemiology and Prevention Unit, Fondazione IRCCS Istituto Nazionale dei Tumori di Milano, Milan (MI), Italy.

|March 25, 2022

Summary

Passive recruitment methods were more effective for advancing clinical trial enrollment than active methods. However, the benefits of passive recruitment did not fully outweigh its drawbacks in the MeMeMe trial.

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Area of Science:

Clinical Trial Recruitment
Preventive Medicine
Metabolic Disease Research

Background:

Clinical trial recruitment is critical for study success.
The MeMeMe trial investigates a Mediterranean diet with or without metformin for preventing age-related chronic diseases.
Understanding recruitment and withdrawal patterns is key to optimizing trial design.

Purpose of the Study:

To report on the recruitment experience of the MeMeMe trial.
To analyze the effectiveness of "active" versus "passive" recruitment strategies.
To identify factors influencing participant withdrawal from the clinical trial.

Main Methods:

Statistical analysis of 2035 volunteers, categorizing recruitment as "active" or "passive".
Logistic regression models were used to assess withdrawal risk factors.
Factors analyzed included recruitment method, sex, age, BMI, and weight change.

Main Results:

"Passive" recruitment (67.6%) was more common than "active" recruitment (32.4%).
Withdrawal rates were similar between active (19.5%) and passive (22.0%) recruitment.
Higher withdrawal risk was associated with being female, older age, and higher baseline BMI. Weight loss in the first year significantly reduced withdrawal risk.

Conclusions:

"Passive" recruitment proved more effective for advancing enrollment in the MeMeMe trial.
Despite higher effectiveness, the advantages of "passive" recruitment were marginal.
Participant characteristics (sex, age, BMI) and adherence (weight change) significantly impact trial retention.