In-depth qualitative interviews identified barriers and facilitators that influenced chief investigators' use of core outcome sets in randomised controlled trials

Indifferent minds, broken system: a critical examination of mental health care provision for Spain's incarcerated population with serious mental illnesses

Background

Spain healthcare system is decentralized, with seventeen autonomous regions overseeing healthcare. However, penitentiary healthcare is managed nationally, except in Catalonia, the Basque Country, and Navarra. These variations impact mental health care provision for inmates with serious mental illness (SMI).

Objective

To delineate differences between regions in terms of mental health care provision for individuals with SMI, available resources, and the perspectives of healthcare professionals operating in the Spanish prison environment.

Methods

Employing an explanatory sequential mixed-method approach, the study conducted an extensive literature review, quantitative data collection through structured questionnaires, and qualitative data collection via focus groups and four in-depth interviews. Analysis involved calculating percentages and ratios for quantitative data and thematic analysis for qualitative data interpretation to comprehensively understand mental healthcare provision.

Results

In December 2021, about 4% of inmates in Spain had SMI. There are three distinct models of mental healthcare within the Spanish prison system. The traditional penitentiary model, representing 83% of the incarcerated population, operates independently under the General Secretariat of Penitentiary Institutions at a national level. This model relies on an average of 5.2 penitentiary General Practitioners (pGP) per 1,000 inmates for psychiatric and general healthcare. External psychiatrists are engaged for part-time psychiatric assessment. Acute psychiatric hospitalization occurs in general nursing modules within penitentiary centers or in Restricted Access Units (RAUs) in reference hospitals. Two penitentiary psychiatric hospitals provide care to unimputable SMI inmates from all over Spain. Innovative penitentiary models, constituting 17% of the prison population, integrate penitentiary healthcare within regional public health systems. The Basque Country features a Mental Health Unit with full-time care teams within the penitentiary center. Catalonia emphasizes community care, providing full-time dedicated psychiatric services within and outside prisons, ensuring continued care in the community. Both models prioritize personnel with specialized mental health training and compensation akin to non-prison healthcare settings.

Conclusions

Regional disparities in penitentiary mental healthcare models in Spain result in resource inequalities, impacting specialized care for inmates with SMI and opportunities for healthcare professionals. The models in the Basque Country and Catalonia offer valuable experiences for penitentiary healthcare.

Uptake of core outcome sets by clinical trialists in China: a protocol

Background

The concept of core outcome sets (COS) has been introduced in China for about 10 years. In recent years, some Chinese researchers also committed to developing COS, though the majority of COS are ongoing. However, there were more than 500 published COS for research in the COMET database by 2020. The extent of availability of COS for the top 25 diseases with the highest burden in China is unknown. In addition, the uptake of COS in clinical trials for these diseases is unknown, along with the knowledge, perceptions, and views of the clinical trialist community in China on the use of COS in relation to choosing outcomes for their research.

Methods

The main burden of disease in China will be identified. Then we will search the COMET database to identify if there are ongoing or completed relevant COS research A COS published since 2012 would be preferred to one published before 2012 for the analysis of COS uptake if one meets the eligibility criteria. We will extract scopes of published eligible COS, including condition, population, interventions, and core outcomes. Then we will search the Chinese Clinical Trial Registry using disease names for each disease that has a published COS. We will assess the overlap in scope between clinical trials and COS. Then we will conduct an online survey and semi-structured interviews to identify the knowledge and perceptions of COS among primary investigators of included clinical trials.

Discussion

This research will fill in gaps between COS and the burden of disease in China. Understanding clinical trialists'knowledge and perceptions of COS may help dissemination and application of COS in the future.

Trial registration

This research is registered in Core Outcome Measures in Effectiveness: https://www.comet-initiative.org/Studies/Details/2563.

Identification and Assessment of Outcome Measurement Instruments in Cauda Equina Syndrome: A Systematic Review

STUDY DESIGN

This was a systematic review of surgically managed Cauda Equina Syndrome (CES) Outcome Measurement Instruments (OMI).

OBJECTIVE

A core outcome set (COS) defines agreed outcomes which should be reported as a minimum in any research study for a specific condition. This study identified OMIs used in the wider CES literature and compare these to the established CESCOS.

METHODS

To identify measurement methods and instruments in the CES surgical outcome evidence base, a systematic review was performed. Medline, Embase and CINAHL plus databases were queried. In addition, a secondary search for validation studies of measurement instruments in CES was undertaken. Identified studies from this search were subject to the COSMIN risk of bias assessment.

RESULTS

In total, 112 studies were identified investigating surgical outcomes for CES. The majority (80%, n = 90) of these OMI studies were retrospective in nature and only 55% (n = 62) utilised a measurement method or instrument. The remaining 50 studies used study specific definitions for surgical outcomes defined within their methods. Of the 59 measurement instruments identified, 60% (n = 38 instruments) were patient reported outcome measures. Only one validated instrument was identified, which was a patient reported outcome measure. The validated instrument was not used in any study identified in the initial search (to identify measurement instruments).

CONCLUSIONS

This review highlights the wide heterogeneity of measurement instruments used in surgically managed CES research. Subsequently, there is need for consensus agreement on which instrument or instruments should be used to measure each core outcome for CES surgical outcomes.

Selective outcome reporting in trials of behavioural health interventions in health psychology and behavioural medicine journals: a review

Selective outcome reporting can result in overestimation of treatment effects, research waste, and reduced openness and transparency. This review aimed to examine selective outcome reporting in trials of behavioural health interventions and determine potential outcome reporting bias. A review of nine health psychology and behavioural medicine journals was conducted to identify randomised controlled trials of behavioural health interventions published since 2019. Discrepancies in outcome reporting were observed in 90% of the 29 trials with corresponding registrations/protocols. Discrepancies included 72% of trials omitting prespecified outcomes; 55% of trials introduced new outcomes. Thirty-eight percent of trials omitted prespecified and introduced new outcomes. Three trials (10%) downgraded primary outcomes in registrations/protocols to secondary outcomes in final reports; downgraded outcomes were not statistically significant in two trials. Five trials (17%) upgraded secondary outcomes to primary outcomes; upgraded outcomes were statistically significant in all trials. In final reports, three trials (7%) omitted outcomes from the methods section; three trials (7%) introduced new outcomes in results that were not in the methods. These findings indicate that selective outcome reporting is a problem in behavioural health intervention trials. Journal- and trialist-level approaches are needed to minimise selective outcome reporting in health psychology and behavioural medicine.

Study found increasing use of core outcome sets in Cochrane systematic reviews and identified facilitators and barriers

OBJECTIVES

In 2019, only 7% of Cochrane systematic reviews (SRs) cited a core outcome set (COS) in relation to choosing outcomes, even though a relevant COS existed but was not mentioned (or cited) for a further 29% of SRs. Our objectives for the current work were to (1) examine the extent to which authors are currently considering COS to inform outcome choice in Cochrane protocols and completed SRs, and (2) understand author facilitators and barriers to using COS.

STUDY DESIGN AND SETTING

We examined all completed Cochrane SRs published in the last 3 months of 2022 and all Cochrane protocols published in 2022 for the extent to which they: (a) cited a COS, (b) searched for COS, (c) used outcomes from existing COS, and (d) reported outcome inconsistency among included studies and/or noted the need for COS. One investigator extracted information; a second extractor verified all information, discussing discrepancies to achieve consensus. We then conducted an online survey of authors of the included SRs to assess awareness of COS and identify facilitators and barriers to using COS to inform outcome choice.

RESULTS

Objective 1: We included 294 SRs of interventions (84 completed SRs and 210 published SR protocols), of which 13% cited specific COS and 5% did not cite but mentioned searching for COS. A median of 83% of core outcomes from cited COS (interquartile range [IQR] 57%-100%) were included in the corresponding SR. We identified a relevant COS for 39% of SRs that did not cite a COS. A median of 50% of core outcomes from noncited COS (IQR 35%-72%) were included in the corresponding SR. Objective 2: Authors of 236 (80%) of the 294 eligible SRs completed our survey. Seventy-seven percent of authors noted being aware of COS before the survey. Fifty-five percent of authors who did not cite COS but were aware of them reported searching for a COS. The most reported facilitators of using COS were author awareness of the existence of COS (59%), author positive perceptions of COS (52%), and recommendation in the Cochrane Handbook regarding COS use (48%). The most reported barriers related to matching of the scope of the COS and the SR: the COS target population was too narrow/broad relative to the SR population (29%) or the COS target intervention was too narrow/broad relative to the SR intervention (21%). Most authors (87%) mentioned that they would consider incorporating missing core outcomes in the SR/update.

CONCLUSION

Since 2019, there is increasing consideration and awareness of COS when choosing outcomes for Cochrane SRs of interventions, but uptake remains low and can be improved further. Use of COS in SRs is important to improve outcome standardization, reduce research waste, and improve evidence syntheses of the relevant effects of interventions across health research.

Using behavioral science to increase core outcome set use in trials

OBJECTIVES

Core outcome sets (COS) are agreed sets of outcomes for use in clinical trials, which can increase standardization and reduce heterogeneity of outcomes in research. Using a COS, or not, is a behavior that can potentially be increased using behavioral strategies. The aim of this study was to identify behavioral intervention components to potentially increase use of COS in trials.

METHODS

This project was informed by the Behavior Change Wheel framework. Two reviewers extracted barriers and facilitators to COS use from four recently published studies examining COS use in trials. Barriers and facilitators were coded to the Capability, Opportunity, Motivation-Behavior (COM-B) model, which forms part of the Behavior Change Wheel. COM-B findings were mapped to intervention functions by two reviewers, and then mapped to behavior change techniques (BCTs). Full-team Affordability, Practicability, Effectiveness/Cost-effectiveness, Acceptability, Side effects/Safety, Equity ratings were used to reach consensus on intervention functions and BCTs. BCTs were operationalized using examples of tangible potential applications and were categorized based on similarity.

RESULTS

Barriers and facilitators were identified for all capability, opportunity and motivation aspects of the COM-B model. Five intervention functions (education, training, enablement, persuasion, and modeling) and 15 BCTs were identified. Thirty-six BCT examples were developed, including providing information on benefits of COS for health research, and information choosing COS. BCT examples are categorized by approaches related to "workshops," "guidance," "audio/visual resources," and "other resources."

CONCLUSION

Study findings represent diverse ways to potentially increase COS use in trials. Future work is needed to examine effects of these behavioral intervention components on COS use. If effective, increased use of COS can improve outcome reporting and minimize outcome heterogeneity and research waste.

Harmonising outcome measurement for child focused domestic abuse interventions. Reflections on the development and implementation of a core outcome set

There is appetite in the UK to better measure the impact of domestic violence and abuse (DVA) interventions on children. The spread of outcomes-based commissioning means outcome measurement is no longer just the territory of academic researchers but is now firmly within the purview of practitioners and policy makers. However, outcomes measured in trials only partially represent the views of those delivering and using services with respect to how success should be defined and captured. Even within trials there is huge inconsistency in the definition and measurement of important endpoints. This yields a body of evidence that is difficult to make sense of, defeating the ends for which it was produced - to improve the response to children and families who have experienced abuse. Development of Core Outcome Sets (COS) is seen as a solution to this problem, by establishing consensus across key stakeholder groups regarding a minimum standard for outcome measurement in trials, and increasingly in service delivery contexts. To date COS development has addressed outcomes relating to health conditions or interventions, with limited application to public health challenges. We reflect on our efforts to develop a COS to evaluate psychosocial interventions for children and families experiencing DVA. We highlight the value of COS development as a mechanism for improving evidence quality and the response to families experiencing abuse. Finally, we make recommendations to researchers and COS guideline developers to support this broader application of COS methodology.

The Uptake of the Core Outcome Set for Non-Specific Low Back Pain Clinical Trials is Poor: A Meta-Epidemiological Study of Trial Registrations

We conducted a meta-epidemiological study on all non-specific low back pain (NSLBP) trial registrations on the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov. We aimed to 1) assess the uptake of the core outcome set (COS) for NSLBP in clinical trials; 2) assess the uptake of the core outcome measurement set for NSLBP in clinical trials; and 3) determine whether specific study characteristics are associated with the COS uptake. After applying the relevant filters for the condition, study type, and phase of the trial, 240 registry entries were included in this study. Only 50 (20.8%) entries showed a full COS uptake, and this rate did not increase over time. Most registry entries that planned to measure physical functioning (n = 152) used the Roland-Morris Disability Questionnaire (n = 74; 48.7%); a small percentage used the numeric rating scale (n = 60; 27.3%) or Short Form-12 (n = 5; 8.3%) if they planned to measure pain intensity (n = 220) or health-related quality of life (n = 60), respectively. Only the planned sample size (OR = 1.02; 95% CI = 1.01, 1.03) showed a significant but small association with COS uptake. The uptake of the COS for NSLBP is poor. Only 21% of the randomized controlled trials aimed to measure all COS domains in their study registration and COS uptake is not increased over time. Great heterogeneity in measurement instruments was also observed, revealing poor core outcome measurement set uptake. PERSPECTIVE: The Core Outcome Set (COS) for non-specific low back pain was published more than 20 years ago. We evaluated whether trial registrations are using this set of outcomes when testing interventions for low back pain. Full uptake was found only in 21% of the sample, and this is not increasing over time. Researchers should use the COS to ensure that trials measure relevant outcomes consistently.

Awareness and experiences on core outcome set development and use amongst stakeholders from low- and middle- income countries: An online survey

Harmonization of outcomes to be measured in clinical trials can reduce research waste and enhance research translation. One of the ways to standardize measurement is through development and use of core outcome sets (COS). There is limited involvement of low- and middle-income country (LMIC) stakeholders in COS development and use. This study explores the level of awareness and experiences of LMIC stakeholders in the development and use of COS. We conducted an online survey of LMIC stakeholders. Three existing COS (pre-eclampsia, COVID-19, palliative care) were presented as case scenarios, and respondents asked to state (with reason(s)) if they would or would not use the COS if they were working in that area. Quantitative data were analyzed descriptively while qualitative data were analyzed thematically. Of 81 respondents, 26 had COS experience, 9 of whom had been involved in COS development. Personal research interests and prevalence of disease are key drivers for initiation/participation in a given COS project. Most respondents would use the COS for pre-eclampsia (18/26) and COVID-19 (19/26) since the development process included key stakeholders. More than half of the respondents were not sure or would not use the palliative care COS as they felt stakeholder engagement was limited and it was developed for a different resource setting. Respondents reported that use of COS can be limited by (i) feasibility of measuring the outcomes in the COS, (ii) knowledge on the usefulness and availability of COS and (iii) lack of wide stakeholder engagement in the COS development process including having patients and carers in the development process. To ensure the development and use of COS in LMICs, collaborations are essential in awareness raising on COS utility, training, and COS development. The COS also needs to be made accessible in locally understandable languages and feasible to measure in LMICs.

Saldanha I, Smith V, Toomey E, Williamson P. Using behavioural science to enhance use of core outcome sets in trials: protocol

Background

Core outcome sets (COS) represent agreed-upon sets of outcomes, which are the minimum that should be measured and reported in all trials in specific health areas. Use of COS can reduce outcome heterogeneity, selective outcome reporting, and research waste, and can facilitate evidence syntheses. Despite benefits of using COS, current use of COS in trials is low. COS use can be understood as a behaviour, in that it is something trialists do, or not do, adequately. The aim of this study is to identify strategies, informed by behaviour change theory, to increase COS use in trials.

Methods

The project will be conducted in two stages, informed by the behaviour change wheel (BCW). The BCW is a theoretically based framework that can be used to classify, identify, and develop behaviour change strategies. In Stage 1, barriers and enablers to COS use will be extracted from published studies that examined trialist's use of COS. Barriers and facilitators will be mapped to the components of COM-B model (capability, opportunity, and motivation), which forms part of the BCW framework. Stage 2 will build on Stage 1 findings to identify and select intervention functions and behaviour change techniques to enhance COS use in trials.

Discussion

The findings of this study will provide an understanding of the behavioural factors that influence COS use in trials and what strategies might be used to target these factors to increase COS use in trials.

The Harmonising Outcome Measures for Eczema (HOME) implementation roadmap

BACKGROUND

Core outcome sets (COS) are consensus-driven sets of minimum outcomes that should be measured and reported in all clinical trials. COS aim to reduce heterogeneity in outcome measurement and reporting, and selective outcome reporting. Implementing COS into clinical trials is challenging. Guidance to improve COS uptake in dermatology is lacking.

OBJECTIVES

To develop a structured practical guide to COS implementation.

METHODS

Members of the Harmonising Outcome Measurement for Eczema (HOME) executive committee developed an expert opinion-based roadmap founded on a combination of a review of the COS implementation literature, the Core Outcome Measures in Effectiveness Trials (COMET) initiative resources, input from HOME members and experience in COS development and clinical trials.

RESULTS

The data review and input from HOME members was synthesized into themes, which guided roadmap development: (a) barriers and facilitators to COS uptake based on stakeholder awareness/engagement and COS features; and (b) key implementation science principles (assessment-driven, data-centred, priority-based and context-sensitive). The HOME implementation roadmap follows three stages. Firstly, the COS uptake scope and goals need to be defined. Secondly, during COS development, preparation for future implementation is supported by establishing the COS as a credible evidence-informed consensus by applying robust COS development methodology, engaging multiple stakeholders, fostering sustained and global engagement, emphasizing COS ease of use and universal applicability, and providing recommendations on COS use. Thirdly, incorporating completed COS into primary (trials) and secondary (reviews) research is an iterative process starting with mapping COS uptake and stakeholders' attitudes, followed by designing and carrying out targeted implementation projects. Main themes for implementation projects identified at HOME are stakeholder awareness/engagement; universal applicability for different populations; and improving ease-of-use by reducing administrative and study burden. Formal implementation frameworks can be used to identify implementation barriers/facilitators and to design implementation strategies. The effect of these strategies on uptake should be evaluated and implementation plans adjusted accordingly.

CONCLUSIONS

COS can improve the quality and applicability of research and, so, clinical practice but can only succeed if used and reported consistently. The HOME implementation roadmap is an extension of the original HOME roadmap for COS development and provides a pragmatic framework to develop COS implementation strategies.

Current trends, barriers, and facilitators of use of core outcome sets in Cochrane systematic reviews: Protocol

Background: Core outcome sets (COS) represent agreed-upon minimum outcomes that should be reported in all studies in a given topic area. Cochrane reviews are considered among the most rigorously conducted systematic reviews (SRs). In 2019, seven of the first 100 published Cochrane SRs (7%) cited a COS in relation to choosing outcomes. A relevant COS existed but was not mentioned (or cited) for 27 of the remaining 93 SRs (29%). Among Cochrane Review Group editors surveyed in 2019, 86% felt that COS should definitely/possibly be used in Cochrane SRs. As of September 2019, the Cochrane Handbook recommends that SR teams consult resources that host relevant COS when choosing outcomes for the SR. Objectives: (1) Examine the extent to which authors are currently considering COS to inform outcome choice in Cochrane protocols and completed SRs. (2) Understand author barriers and facilitators of using COS in Cochrane protocols and completed SRs. Methods: We will examine the extent to which all Cochrane SRs published in the last 3 months of 2022 and all Cochrane protocols published in 2022: (a) cited a COS, (b) searched for COS, and (c) reported outcome inconsistency among included studies and/or noted the need for COS. One investigator will extract information from SRs and protocols; a second extractor will verify all information, discussing discrepancies to achieve consensus. Using Jisc Online Surveys ®, we will conduct an online anonymous survey of authors of all the included completed SRs and protocols to assess author awareness of COS and identify barriers and facilitators of using COS to inform outcome choice. Discussion: This study will provide key information regarding uptake of COS by Cochrane SR authors and the barriers and facilitators that they experience. Our findings will inform approaches to increasing awareness and uptake of COS in future SRs, both with and beyond Cochrane.

Utility of the capability, opportunity, and motivation behaviour (COM-B) model in explaining the negative association between pre-pregnancy body mass index and exclusive breastfeeding at six weeks postpartum

The mechanisms underlying the negative associations between pre-pregnancy body mass index (BMI) and exclusive breastfeeding remain poorly understood. Thus, the study aimed to determine whether the negative associations between high pre-pregnancy BMI and exclusive breastfeeding at six weeks postpartum are mediated by components of the capability, opportunity, and motivation behaviour (COM-B) model. In this prospective observational study, we assigned 360 primiparous women to a pre-pregnancy overweight/obese group (n = 180) and a normal-BMI group (n = 180). A structural equation model was designed to study how capabilities (onset of lactogenesis II, perceived milk supply, breastfeeding knowledge, and postpartum depression), opportunities (pro-breastfeeding hospital practices, social influence, social support), and motivations (breastfeeding intention, breastfeeding self-efficacy, and attitudes towards breastfeeding) affected exclusive breastfeeding at six weeks postpartum in groups of women with different pre-pregnancy BMIs. In all, 342 participants (95.0%) possessed complete data. Women with high pre-pregnancy BMI were less likely to exclusively breastfeed at six weeks postpartum than women with a normal BMI were. We observed a significant negative direct effect of high pre-pregnancy BMI on exclusive breastfeeding at six weeks postpartum and a significantly negative indirect effect of high pre-pregnancy BMI via the explanatory mediating variables of capabilities (onset of lactogenesis II, perceived milk supply, and breastfeeding knowledge) and motivations (breastfeeding self-efficacy) on exclusive breastfeeding at six weeks postpartum. Our findings support certain capabilities (onset of lactogenesis II, perceived milk supply, and breastfeeding knowledge) and motivations (breastfeeding self-efficacy), partially explaining the negative association between high pre-pregnancy BMI and exclusive breastfeeding outcome. We suggest that interventions aimed at promoting exclusive breastfeeding among women with high pre-pregnancy BMI should address the capacity and motivation factors specific to this population.

Irish funder guidance increased searching for, and uptake of, core outcome sets

OBJECTIVES

Assess the impact of the Health Research Board (HRB) Ireland guidance on the uptake of core outcome sets (COSs).

STUDY DESIGN AND SETTING

(1) Information on COS use, searching of the Core Outcome Measures in Effectiveness Trials (COMET) database, and rationale for outcome selection were extracted from HRB funding applications (2) COMET was searched for relevant COS availability at the time of application or developed since (3) principal investigator choices were explored through online surveys.

RESULTS

Out of 187 funding applications, 44% (n = 82) searched the COMET database, and 13% (n = 11) of those found a relevant COS to inform their outcomes. Four applicants proposed COS development. However, 84% (n = 156) of applications had no relevant COS available at the time of submission, as identified by subsequent author COMET search. Among 84 principal investigators who participated in the surveys, 10 (12%) found and used a COS and 19 (42%) of the 45 respondents who did not have reference to COMET had searched the COMET database. A new question in the application form prompted a rise in those reporting a search of the COMET database from 6% to 99%.

CONCLUSION

The study found low COS uptake in funding applications, but a new application question prompted an increase in reporting searches of the COMET database. Funder guidance promoted COS awareness and use, but more efforts are needed to facilitate COS development and adoption in clinical research.

Review finds core outcome set uptake in new studies and systematic reviews needs improvement

OBJECTIVE

To review evidence about the uptake of core outcome sets (COS). A COS is an agreed standardized set of outcomes that should be measured and reported, as a minimum, in all clinical trials in a specific area of health or health care.

STUDY DESIGN AND SETTING

This article provides an analysis of what is known about the uptake of COS in research. Similarities between COS and outcomes recommended by stakeholders in the evidence ecosystem is reviewed, and actions taken by them to facilitate COS uptake described.

RESULTS

COS uptake is low in most research areas. Common facilitators relate to trialist awareness and understanding. Common barriers were not including in the development process all specialties who might use the COS, and the lack of recommendations for how to measure the outcomes. Increasingly, COS developers are considering strategies for promoting uptake earlier in the process, including actions beyond traditional dissemination approaches. Overlap between COS and outcomes in regulatory documents and health technology assessments is good. An increasing number and variety of organisations are recommending COS be considered.

CONCLUSION

We suggest actions for various stakeholders for improving COS uptake. Research is needed to assess the impact of these actions to identify effective evidence-based strategies.

Saldanha I, Smith V, Toomey E, Williamson P. Using behavioural science to enhance use of core outcome sets in trials: protocol

Background: Core outcome sets (COS) represent agreed-upon sets of outcomes, which are the minimum that should be measured and reported in all trials in specific health areas. Use of COS can reduce outcome heterogeneity, selective outcome reporting, and research waste, and can facilitate evidence syntheses. Despite benefits of using COS, current use of COS in trials is low. COS use can be understood as a behaviour, in that it is something trialists do, or not do, adequately. The aim of this study is to identify stakeholder-prioritised strategies, informed by behaviour change theory, to increase COS use in trials. Methods: The project will be conducted in three stages, informed by the behaviour change wheel (BCW). The BCW is a theoretically based framework that can be used to classify, identify, and develop behaviour change strategies. In Stage 1, barriers and enablers to COS use will be extracted from published studies that examined trialist’s use of COS. Barriers and facilitators will be mapped to the components of COM-B model (capability, opportunity, and motivation), which forms part of the BCW framework. Stage 2 will build on Stage 1 findings to identify and select intervention functions and behaviour change techniques to enhance COS use in trials. Stage 3 will involve an online stakeholder consensus meeting including trialists, healthcare professionals, and patient/public representatives. The purpose of the meeting is to prioritise identified intervention approaches that will inform future research to increase COS use. Discussion: The findings of this study will provide an understanding of the behavioural factors that influence COS use in trials, what strategies might be used to target these factors to increase COS use, and what strategies key stakeholders perceive as especially important in future research to enhance COS use in trials.