Participant retention

This section contains the following:

Introduction
Illustrative examples - CRASH trial
Illustrative examples - Perinatal care trial
Additional resources
Further reading

Introduction

After the subjects are recruited into the trial, strategies aimed to conduct an adequate follow-up must be considered. This is a critical point, especially in long-term studies, or in trials where the outcome(s) of interest take some time to develop after recruitment. Primary and secondary endpoints must be systematically recorded, as well as any adverse event. Follow-up also includes a monitoring of compliance, protocol deviations, contamination, and co-interventions if appropriate, according to the trial design and objectives, as well as a documentation of losses and dropouts. This information in a randomized controlled trial is important, as the interpretation of the trial results must consider treatment acceptability and the level of non-adherence to therapy. Furthermore, in pragmatic trials the level of compliance must be seen as one aspect of the assessment of treatment, as it reflects behavior in clinical practice outside the trial setting.

Whatever the purpose of the trial, data collection is only possible if the staff remain actively involved throughout the duration of the trial and if the subjects are willing to maintain their participation in the study.

In order to ensure continuing commitment to a trial investigators must develop post-recruitment retention strategies (preferably at the protocol preparation phase) listing all the activities to be conducted during the trial in order to achieve these goals e.g. collaborator meetings, newsletters, posters, merchandise. These will often have resource implications and should be budgeted for.

Many recommendations exist for managing follow-up. However, many have not been formally evaluated. Researchers should balance the potential benefits of each component of the plan with the main objectives of the trial on one hand, with the resources and logistics required for its execution, on the other.

Things to consider when writing a protocol

Describe the strategy/process to keep the trial staff interest
Describe the strategy/process to keep the patient interest
Explain the procedures for maintaining records of the patient’s contact details
Explain the procedures for monitoring protocol compliance, protocol deviations, contamination and co-interventions during the conduct of the trial
Explain the procedures for managing potential losses and dropouts during the conduct of the trial and if necessary for the trial objectives, identify corrective measures
Include the activities in the Manual of Operations
Include the strategy in the budget.

Illustrative example - CRASH trial
Co-ordinating Centre responsibilities • Provide study materials and a 24-hour randomisation (and unblinding) service • Give collaborators regular information about the progress of the study • Help ensure complete data collection at discharge and at six months • Respond to any questions (e.g. from collaborators) about the trial (CRASH Trial - go to protocol) )

Illustrative example - Perinatal care trial
The study subjects will be the health professionals working in participating hospitals, but the main outcomes will be measured among women having a delivery. However, there will be no follow up with the women, thus no special activities are planned with them. We will monitor the activities of participating health professionals in relation with the compliance of the intervention, with the aim of (1) measuring the activities that will be considered as process outcome and (2) detecting protocol violations and make efforts to correct them. (CLAP Trial - go to protocol) go to protocol )

Illustrative example - Perinatal care trial

The study subjects will be the health professionals working in participating hospitals, but the main outcomes will be measured among women having a delivery. However, there will be no follow up with the women, thus no special activities are planned with them.

We will monitor the activities of participating health professionals in relation with the compliance of the intervention, with the aim of (1) measuring the activities that will be considered as process outcome and (2) detecting protocol violations and make efforts to correct them. (CLAP Trial - go to protocol)

go to protocol )

Additional resources

Checklist for keeping the participants interested

This is a checklist for keeping the participants interested

Checklist for keeping the trial staff interested

This is a checklist for keeping the trial staff interested.

Sample questionnaire booklets and treatment packs

These are a selection of questionnaire booklets and treatment packs that have been previously used to retain participants.

Sample contact form

This is an example of a contact from used in the MAGPIE trial to enable tracing of trial participants.

Sample newsletters: Magpie and CRASH

These are a selection of newsletters that have been previously used to maintain enthusiasm.

Resource Centre for Randomised Trials (RCRT)

The Resource Centre for Randomised Trials (RCRT) aims to provide a central and generic archive of resources relevant to the process of developing and doing trials. This will help maximise the overall investment made in trials. To ensure ease of access, whenever feasible the materials within this library will be accessible via a website that is regularly updated.