Skip to main content

Community participatory learning and action cycle groups to reduce type 2 diabetes in Bangladesh (D:Clare): an updated study protocol for a parallel arm cluster randomised controlled trial

A Study protocol to this article was published on 29 March 2021


The “Diabetes: Community-led Awareness, Response and Evaluation” (D:Clare) trial aims to scale up and replicate an evidence-based participatory learning and action cycle intervention in Bangladesh, to inform policy on population-level T2DM prevention and control.

The trial was originally designed as a stepped-wedge cluster randomised controlled trial, with the interventions running from March 2020 to September 2022. Twelve clusters were randomly allocated (1:1) to implement the intervention at months 1 or 12 in two steps, and evaluated through three cross-sectional surveys at months 1, 12 and 24. However, due to the COVID-19 pandemic, we suspended project activities on the 20th of March 2020. As a result of the changed risk landscape and the delays introduced by the COVID-19 pandemic, we changed from the stepped-wedge design to a wait-list parallel arm cluster RCT (cRCT) with baseline data. We had four key reasons for eventually agreeing to change designs: equipoise, temporal bias in exposure and outcomes, loss of power and time and funding considerations.

Trial registration ISRCTN42219712. Registered on 31 October 2019.

Peer Review reports

The D:Clare trial (Diabetes: Community-Led Awareness, Response and Evaluation) was designed as a cluster randomised stepped-wedge trial, in Alfadanga Upazilla, Faridpur District, Bangladesh (ISRCTN42219712) [1]. The trial aims to evaluate the impact of a scaled-up community-based participatory learning and action (PLA) cycle intervention to prevent type 2 diabetes (T2DM) in a population of 120,000 people. The study began in January 2020, with a public consent and randomisation ceremony including community and Ministry of Health and Family Welfare representatives, on the grounds that all communities in the Upazilla would eventually receive the intervention in line with the stepped-wedge approach.

Bangladesh reported its first confirmed cases of SARS-CoV-2 on the 8th of March 2020. Due to concerns about infection risk to both staff and communities, we made a decision to suspend all field-based project activities on the 20th of March 2020 (Fig. 1). Early in the pandemic, evidence emerged that uncontrolled hyperglycaemia and T2DM were risks for severe COVID-19 infections and mortality, alongside older age, obesity and heart disease [2,3,4]. Given the focus and nature of our PLA intervention, we were therefore particularly conscious that continuing the trial may have increased risks amongst vulnerable populations with non-communicable diseases. The status of the trial at the point of suspension is summarised in Table 1. Bangladesh subsequently entered into a nationwide government-declared lockdown from the 23rd of March to the 30th of May 2020, and restrictions on mass gatherings continued until the 1st of September 2020 [5]. The second serious COVID-19 wave began in March 2021, and lockdowns were again implemented between 5th April–21st April 2021 and 1st July–11th August 2021.

Table 1 Status of the D:Clare stepped-wedge trial at the point of COVID-19 field activity suspension on the 20th of March 2020

This short article summarises the changes to our original trial design, in line with the CONSERVE 2021 Statement recommendations that trials impacted by extenuating circumstances should report on modifications [6]. We detail the considerations and rationale for these changes, which may be of relevance to other randomised controlled trials underway in dynamic contexts.

Change in trial design

As a result of the changed risk landscape and the delays introduced by the COVID-19 pandemic, we decided to change from a stepped-wedge (SW-RCT) to a wait-list parallel arm cluster RCT (cRCT) with baseline data. Conceptually, our wait-list design is a parallel arm cRCT but with a commitment to implement the intervention to control clusters at the end of the trial evaluation. As detailed in Table 2, this differs from our stepped-wedge trial design in terms of the timing of roll-out of the intervention across all clusters, timing of cross-sectional data collection for evaluation, and in terms of how clusters are exposed over time, i.e. the allocated exposure (intervention or control) does not change during the trial evaluation. Our original SW design had two steps and was planned to take 30 months, with cross-sectional surveys done at months 1, 12 and 24 of intervention implementation (Fig. 1) [1]. The SW design should be resilient to temporal changes within a population, and so our original approach remained valid. However, the interruption of activities and the nature of the COVID-19 pandemic meant this design was no longer the most efficient and appropriate to meet project goals, and we presented alternative options to our Trial Steering Committee for consideration. We also engaged with community and government stakeholders to check that the proposed adaptions would be acceptable. We had four key reasons for eventually agreeing to change designs.

Table 2 Summary of key changes from original stepped-wedge design to parallel arm wait-list trial
Fig. 1
figure 1

Planned D:Clare project timeline and COVID-19 interruptions


The D:Clare PLA intervention was shown to be effective in reducing both the 2-year cumulative incidence and prevalence of T2DM in a rural Bangladesh population during the D-Magic trial [7]. This was part of the justification for us using an SW-RCT originally, as evidence of population benefit existed, and our aim was to determine effectiveness at scale in a similar but new population. However, with the considerable change in context and the potential need to adapt the intervention components and delivery, the lack of equipoise around the PLA intervention we had previously argued was less clear. Specifically, our intervention encourages groups to meet, encourages participation from those with T2DM and NCDs and encourages collective action. In a context where COVID-19 preventive measures focused on restricting inter-household interactions, we hypothesised that PLA’s mechanism of action may be affected.

Further, if COVID-19 cases were not being diagnosed in this community setting, then group meetings had the potential to cause harm. However, by the end of 2020, there was evidence that outdoor environments posed a lower risk of transmission than indoor, crowded spaces, especially if this can be combined with the use of face masks, hand hygiene and physical distancing. Given the potential for our intervention to improve T2DM management (a key risk for poor COVID-19 outcomes), the ability to deliver in a way that would reduce transmission, and the inclusion of new stop/start rules (Fig. 2), we felt this risk could be sufficiently mitigated. We therefore decided we met the criteria for equipoise around the intervention needed to do a parallel arm cRCT.

Fig. 2
figure 2

D:Clare trial stop, pause and start rules for COVID-19 adaptation

Temporal bias in exposure and outcomes

We also hypothesised that health literacy, care-seeking, dietary and physical activity behaviours, and the epidemiology of diabetes could be vastly different after lockdown restrictions were lifted — and therefore from our baseline survey. This in itself should not invalidate the SW-RCT design, but could make the interpretation and communication of the intervention impact on primary and secondary outcomes more complicated. The timing of intervention delivery relative to lockdown and social distancing measures was also likely to have an important influence on the uptake, delivery and effectiveness of the intervention. This may result in variable intervention effects between the two steps of SW implementation, which could be assessed through process evaluation, but again would complicate interpretation.

Loss of power

Our power calculation was based on achieving at least an 80% response in the first cross-sectional survey. However, we only achieved 72% recruitment at the time of interruption and saw variation in rates between clusters (49–89%). In order to then ensure the SW-RCT was sufficiently powered, we would have had to increase the sample size of all the subsequent surveys. Switching to a parallel arm trial which uses both a new baseline and endline data (assuming an autocorrelation of 0.4), we could achieve 78% power for a 30% reduction in the primary outcome and considered this a feasible alternative. The change to the number and timing of surveys and the inclusion of baseline data in outcome evaluation are notable changes to our original protocol (Table 2).

Time and funding

Finally, there was a very practical issue that we no longer had enough time to complete the SW-RCT design within the overall 36-month funded project period, using our 12-month staggered two-step design. By switching to a parallel cRCT we could complete the effectiveness evaluation within the funded project timeline, however, recognising that the parallel arm design would determine the intervention impact on a smaller population scale than we had originally intended. We then planned to source project extensions and explore the reallocation of resources to ensure that at a minimum the intervention could be delivered in control clusters as was promised to communities, but without incurring ongoing concurrent process, economic and impact evaluation costs.

Protocol updates

We made changes to three key areas of the trial protocol: study design, intervention and sample size; no amendments were made to the trial procedures for population eligibility, sampling, randomisation, blinding, data collection, or analysis of the primary or secondary outcomes. A list of registered trial protocol amendments in our ISRCTN record is summarised in Table 3.

Table 3 Summary of registered trial protocol revisions in the D:Clare ISRCTN record

We also set out COVID-19 standard operating procedures, with new stop-start rules (Fig. 2), and a COVID-19 safety protocol for staff and study participants, and consulted with a Data Monitoring and Safety Board on these infection prevention measures. For the intervention, we made the following modifications to incorporate COVID-19 measures: holding two meetings per village per month to allow for smaller groups but with the same coverage; inclusion of COVID-19 health information; re-organised meeting content to be delivered over a minimum of 13 instead of the planned 18 meetings (Table 2).

Current trial status

As of 22/04/2022: We completed a new baseline survey on 25/02/2021, with a response rate of 1,392 from 1,584 (87.9%) sampled participants, which forms the parallel arm cRCT baseline data. A total of 213 PLA groups have been formed in 6 of the 12 study clusters, and have completed 11 of a minimum of 13 planned meetings. The endline survey will be completed between August and October 2022.

Protocol version 3.0 (16/06/2021)

Availability of data and materials

Data required to support the protocol can be supplied on request.



Diabetes: Community-Led Awareness, Response and Evaluation


Non-communicable disease


Participatory learning and action


Randomised controlled trial


Stepped-wedge randomised controlled trial


Type 2 diabetes mellitus


  1. King C, Pires M, Ahmed N, et al. Community participatory learning and action cycle groups to reduce type 2 diabetes in Bangladesh (D:Clare trial): study protocol for a stepped-wedge cluster randomised controlled trial. Trials. 2021;22(1):235.

    Article  PubMed  PubMed Central  Google Scholar 

  2. Zhu L, She Z-G, Cheng X, et al. Association of blood glucose control and outcomes in patients with COVID-19 and pre-existing type 2 diabetes. Cell Metabolism. 2020;31(6):1068-1077.e3.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Ho FK, Petermann-Rocha F, Gray SR, et al. Is older age associated with COVID-19 mortality in the absence of other risk factors? general population cohort study of 470,034 participants. PLOS ONE. 2020;15(11):e0241824.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Mesas AE, Cavero-Redondo I, Álvarez-Bueno C, et al. Predictors of in-hospital COVID-19 mortality: a comprehensive systematic review and meta-analysis exploring differences by age, sex and health conditions. PLOS ONE. 2020;15(11):e0241742.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Siam MHB, Hasan MM, Tashrif SM, Rahaman Khan MH, Raheem E, Hossain MS. Insights into the first seven-months of COVID-19 pandemic in Bangladesh: lessons learned from a high-risk country. Heliyon. 2021;7(6):e07385.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Orkin AM, Gill PJ, Ghersi D, et al. Guidelines for reporting trial protocols and completed trials modified due to the COVID-19 pandemic and other extenuating circumstances: the CONSERVE 2021 statement. Jama. 2021;326(3):257–65.

    Article  CAS  PubMed  Google Scholar 

  7. Fottrell E, Ahmed N, Morrison J, et al. Community groups or mobile phone messaging to prevent and control type 2 diabetes and intermediate hyperglycaemia in Bangladesh (DMagic): a cluster-randomised controlled trial. Lancet Diabetes Endocrinol. 2019;7(3):200–12.

    PubMed  PubMed Central  Google Scholar 

Download references


We thank the members of our trial steering committee: Dr David Beran (Chair), Prof Graham Hitman, Prof Sarah Hawkes, Prof Anthony Costello, Prof Edward Gregg, Dr Jennifer Thompson, Prof Audrey Prost, and Prof Justine Davies. We would also like to acknowledge the communities and community leaders for their engagement with the project.


The trial is funded by the UK Medical Research Council (ref: MR/T023562/1) under the Global Alliance for Chronic Diseases (GACD) Diabetes Programme. Peer review of the grant application provided input into the study proposal. Beyond that, the funder has no role in the design of the study, data collection, analysis and interpretation, or the write-up of the findings.

Author information

Authors and Affiliations



EF is the principal investigator. He led the design of the study, wrote the first draft of the study protocol, and will participate in the analysis and interpretation of data. AK is the project manager of the trial, overseeing all activities. CK is a senior researcher on the project, supporting the design, analysis and interpretation of data, and overseeing the data collection and management system. MP is a research assistant on the study, contributing to the design, analysis and interpretation of data. JM is a senior researcher on the project, leading the design, analysis and interpretation of the process evaluation. HHB is the senior researcher on the project, leading the economic evaluation and equity components. AC is the trial statistician, contributed to the design of the study and will participate in the analysis and interpretation of data. NA contributed to protocol development, fieldworker training, and development of interventions. SKS coordinates survey data collection and processes and will participate in the analysis and interpretation of data. TN contributed to the design of interventions and is responsible for intervention implementation. KAk contributed to the design of the process evaluation. AKAK provides technical oversight. KAz is the project director, contributed to the design of the study, leads the implementation of the trial and will participate in the interpretation of data. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Edward Fottrell.

Ethics declarations

Ethics approval and consent to participate

Written informed consent will be obtained from all survey and interview participants by study staff. Community consent was sought from community leaders prior to randomisation and intervention implementation. Ethical approvals were provided by the University College London Research Ethics Committee (ref: 4199/007) and the Ethical Review Committee of the Diabetic Association of Bangladesh (ref: BADAS-ERC/E/19/00276).

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

King, C., Pires, M., Ahmed, N. et al. Community participatory learning and action cycle groups to reduce type 2 diabetes in Bangladesh (D:Clare): an updated study protocol for a parallel arm cluster randomised controlled trial. Trials 24, 218 (2023).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: