An embedded randomised controlled retention trial of personalised text messages compared to non-personalised text messages in an orthopaedic setting

Trial Forge Guidance 4: a guideline for reporting the results of randomised Studies Within A Trial (SWATs)

BACKGROUND

Evidence to support decisions on trial processes is minimal. One way to generate this evidence is to use a Study Within A Trial (SWAT) to test trial processes or explore methodological uncertainties. SWAT evidence relies on replication to ensure sufficient power and broad applicability of findings. Prompt reporting is therefore essential; however, SWAT publications are often the first to be abandoned in the face of other time pressures. Reporting guidance for embedded methodology trials does exist but is not widely used. We sought therefore to build on these guidelines to develop a straightforward, concise reporting standard, which remains adherent to the CONSORT guideline.

METHODS

An iterative process was used to develop the guideline. This included initial meetings with key stakeholders, development of an initial guideline, pilot testing of draft guidelines, further iteration and pilot testing, and finalisation of the guideline.

RESULTS

We developed a reporting guideline applicable to randomised SWATs, including replications of previous evaluations. The guideline follows the Consolidated Standards for Reporting Trials (CONSORT) statement and provides example text to ensure ease and clarity of reporting across all domains.

CONCLUSIONS

The SWAT reporting guideline will aid authors, reviewers, and journal editors to produce and review clear, structured reports of randomised SWATs, whilst also adhering to the CONSORT guideline.

TRIAL REGISTRATION

EQUATOR Network - Guidelines Under Development ( https://www.equator-network.org/library/reporting-guidelines-under-development/reporting-guidelines-under-development-for-clinical-trials/#SWAT ). Registered on 25 March 2021.

Personalised versus standard text message prompts for increasing trial participant response to telephone follow-up: an embedded randomised controlled retention trial

BACKGROUND

Improving retention within randomised controlled trials is important. The effectiveness of different strategies can be assessed using a Study Within A Trial (SWAT). Previous research has shown personalised text message reminders improve clinic attendance rates; however, the results are mixed on improving postal questionnaire return. This SWAT aims to assess whether personalised text message reminders improve completion rates for scheduled telephone follow-ups.

METHODS

This SWAT is a two-arm, multi-centre randomised controlled trial with equal allocation. The host trial was the Melatonin for Anxiety prior to General anaesthesia In Children trial (ISRCTN 18296119), where the child's caregiver was to answer a scheduled telephone follow-up 14 days post-surgery; participants for the SWAT were therefore the caregiver. Text messages were sent 24-48 h before the scheduled call and the personalised version contained the first name of the caregiver which was omitted in the non-personalised version. The primary outcome was questionnaire completion rate, defined as the proportion of caregivers successfully contacted, and completed any of the questionnaires, over the telephone within the follow-up window (day 14 + 7 days).

RESULTS

The SWAT included 100 of the 110 (91%) participants randomised into the host trial. Randomisation within the SWAT was equal between non-personalised (n = 50) and personalised (n = 50) interventions. The overall questionnaire response rate was 73% with a difference between the two interventions of 68% in the non-personalised text message arm and 78% in the personalised text message arm. The adjusted absolute risk difference was 7.1% (95% confidence interval = -10.2%, 24.4%). There was no difference in either the time to response or the number of contact attempts between the two interventions.

CONCLUSIONS

There is some evidence that personalised text messages could be effective at increasing response rates when data is collected via telephone and in a population of caregivers for paediatric trial participants. However, similar SWATs have shown mixed results. Given the low-cost and low risks associated with personalising text message reminders, this SWAT could be implemented easily in other RCTs scheduling telephone follow-up appointments.

TRIAL REGISTRATION

ISRCTN 18296119 , SWAT 35 (MRC Northern Ireland Network for Trials Methodology Network).

The effect of personalised versus non-personalised study invitations on recruitment within the ENGAGE feasibility trial: an embedded randomised controlled recruitment trial

Background

Recruitment into clinical trials is challenging and there is a lack of evidence on effective recruitment strategies. Personalisation of invitation letters is a potentially pragmatic and feasible way of increasing recruitment rates at a low-cost. However, there is a lack of evidence concerning the effect of personalising of study invitation letters on recruitment rates.

Methods

We undertook a Study Within A Trial (SWAT) to investigate the effect of personalised versus non-personalised study invitation letters on recruitment rates into the host feasibility trial ENGAGE, a feasibility study of an internet-administered, guided, Low Intensity Cognitive-Behavioural Therapy based self-help intervention for parents of children previously treated for cancer. An intervention group (n = 254) received a personalised study invitation letter and the control group (n = 255) received a non-personalised study invitation letter. The primary outcome was the proportion of participants in the intervention group and the control group enrolled into the ENGAGE host feasibility trial. Secondary outcomes relating to the recruitment and screening process, and retention were examined. Differences in proportions between groups for the primary and secondary outcomes were estimated using logistic regression.

Results

Of the 509 potential participants, 56 (11.0%) were enrolled into the ENGAGE host feasibility trial: personalised: 30/254 (11.8%) and non-personalised: 26/255 (10.2%). No statistically significant effect on personalisation of enrolment was found (OR 1.18, 95% CI 0.68–2.06). No statistically significant differences were found for any secondary outcome.

Conclusions

Personalisation of study invitations had no effect on recruitment. However, given the small study sample size in the present SWAT, and lack of similar embedded recruitment RCTs to enable a meta-analysis, additional SWATs to examine the personalisation of study invitation letters are warranted.

Trial registration

ISRCTN57233429; ISRCTN18404129; SWAT 112, Northern Ireland Hub for Trials Methodology Research SWAT repository (2018 OCT 1 1231) (https://www.qub.ac.uk/sites/TheNorthernIrelandNetworkforTrialsMethodologyResearch/FileStore/Filetoupload,939618,en.pdf).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01553-5.