Promoting group identity to improve questionnaire return rates in a multicentre randomised controlled trial

A theory-based intervention for promoting group identity to improve questionnaire return rates in the MARCH multicentre randomised controlled trial: a Study Within a Trial (SWAT)

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN16675252

Enrollment

1172

Registered

2021-11-03

Start date

2022-02-17

Completion date

Unknown

Last updated

2026-08-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Trial follow up/retention Other

Interventions

Participants will be randomised (1:1:1, using mixed block sizes) to one of three arms comprising two SWAT group identity intervention arms (S1 and S2) and one control arm (S3). The randomisation proce

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. MARCH trial participants who have regained capacity 2. Given consent to continue participation in the main trial 3. Who have been discharged from hospital

Exclusion criteria

Exclusion criteria: Does not meet the inclusion criteria

Design outcomes

Primary

Measure	Time frame
The return rate for questionnaires sent to participants at 6 months. The researchers will compare the combination of S1 and S2 versus S3 to assess the impact of increasing the salience of the MARCH trial as a “group” on the return rate. They will also compare S1 versus S2 to assess the additional impact of sending a promotional item on the return rate.	—

Secondary

Measure	Time frame
1. Group identification at 6 months post-randomisation, measured using the single-item social identification instrument and a study-specific group membership Likert scale question. The researchers will compare the combination of S1 and S2 versus S3 to assess the impact of increasing the salience of the MARCH trial as a “group” on group identification. They will also compare S1 versus S2 to assess the additional impact of sending a promotional item on group identification 2. Total costs associated with embedding the SWAT in the MARCH trial; a spreadsheet of the trial resources and related costs (e.g. trial team time input, consumables) associated with the SWAT will be maintained prospectively over the study period by the trial team to allow total costs to be calculated at the end of the study (51-month study duration) 3. Cost per additional questionnaire returned; this will be calculated as the incremental cost of embedding the SWAT divided by the incremental number of questionnaires returned at the end of the study (51-month study duration)	—

Measure

Time frame

1. Group identification at 6 months post-randomisation, measured using the single-item social identification instrument and a study-specific group membership Likert scale question. The researchers will compare the combination of S1 and S2 versus S3 to assess the impact of increasing the salience of the MARCH trial as a “group” on group identification. They will also compare S1 versus S2 to assess the additional impact of sending a promotional item on group identification 2. Total costs associated with embedding the SWAT in the MARCH trial; a spreadsheet of the trial resources and related costs (e.g. trial team time input, consumables) associated with the SWAT will be maintained prospectively over the study period by the trial team to allow total costs to be calculated at the end of the study (51-month study duration) 3. Cost per additional questionnaire returned; this will be calculated as the incremental cost of embedding the SWAT divided by the incremental number of questionnaires returned at the end of the study (51-month study duration)

—

Countries

England, Northern Ireland, Scotland, United Kingdom, Wales

Contacts

Public ContactNaomi Dickson

MARCH@nictu.hscni.net+44 (0)28961 51447

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Aug 25, 2026