Core Outcome Measures In Effectiveness Trials Initiative Research Articles

Outcomes of physiotherapy for people living with bronchiectasis: qualitative study to inform development of a core outcome set

IntroductionEvidence of the effectiveness of physiotherapy for bronchiectasis is inconsistent, partly due to variation in the selection and reporting of outcomes in clinical trials. This qualitative study is a component of the development of a core outcome set (COS). The COS will identify a minimum group of outcomes for use in clinical trials of physiotherapy considering the views of researchers, patients, and clinicians. ObjectivesTo identify outcomes for use in physiotherapy research that are important to patients and physiotherapists and to explain their significance. MethodsSemi-structured interviews were conducted with adult patients with bronchiectasis who received physiotherapy, in addition to physiotherapists clinically involved in bronchiectasis care. Interviews were audio recorded and transcribed verbatim. Thematic analysis was used to identify, classify, and explain the significance of outcomes. Outcomes were mapped into the list created from literature review and classified into domains. ResultsWe interviewed 18 participants from four countries covering a range of experiences in different settings. Seventy outcomes were identified and grouped into 15 domains. Thirty-three outcomes were not previously reported in the literature. Thematic analysis revealed exacerbations, quality of life, use of healthcare resources, patient-reported symptoms, physical functioning, and sputum as the prominent themes reported by both patients and physiotherapists. ConclusionsThis qualitative study highlighted the importance of considering stakeholder perspectives when planning research trials. Outcomes identified will be used to inform the next phase of COS development. RegistrationThis study is part of the COS development project registered with the Core Outcome Measures in Effectiveness Trials initiative (COMET) https://www.comet-initiative.org/Studies/Details/1931 Contribution of the paper•The impact of physiotherapy in bronchiectasis is complex and multidimensional, generating numerous outcomes to be considered in research.•Some outcomes considered important to patients and physiotherapists may inform future trials as they differed from those reported in literature.•This study ensures that the views of patients and physiotherapists are considered in development of the core outcome set.

Qualitative study exploring which research outcomes best reflect women’s experiences of heavy menstrual bleeding: stakeholder involvement in development of a core outcome set

ObjectiveThis work contributed to the development of a core outcome set (COS) for heavy menstrual bleeding (HMB). The objective was to determine which research outcomes best reflect how HMB affects...

Development of an international core outcome set for treatment trials in necrotizing enterocolitis—a study protocol

AimNecrotizing enterocolitis (NEC) is the most lethal disease of the gastrointestinal tract of preterm infants. New and existing management strategies need clinical evaluation. Large heterogeneity exists in the selection, measurement, and reporting of outcome measures in NEC intervention studies. This hampers meta-analyses and the development of evidence-based management guidelines. We aim to develop a Core Outcome Set (COS) for NEC that includes the most relevant outcomes for patients and physicians, from moment of diagnosis into adulthood. This COS is designed for use in NEC treatment trials, in infants with confirmed NEC.MethodsThis study is designed according to COS-STAD (Core Outcome Set-STAndards for Development) recommendations and the COMET (Core Outcome Measures in Effectiveness Trials) Initiative Handbook. We obtained a waiver from the Ethics Review Board and prospectively registered this study with COMET (Study 1920). We will approach 125 clinicians and/or researchers from low-middle and high-income countries based on their scientific output (using SCIVAL, a bibliometric tool). Patients and parents will be approached through local patient organisations. Participants will be separated into three panels, to assess differences in priorities between former patients and parents (1. lay panel), clinicians and researchers involved in the neonatal period (2. neonatal panel) and after the neonatal period (3. post-neonatal panel). They will be presented with outcomes currently used in NEC research, identified through a systematic review, in a Delphi process. Eligible outcome domains are also identified from the patients and parents’ perspectives. Using a consensus process, including three online Delphi rounds and a final face-to-face consensus meeting, the COS will be finalised and include outcomes deemed essential to all stakeholders: health care professionals, parents and patients’ representatives. The final COS will be reported in accordance with the COS-Standards for reporting (COS-STAR) statement.ConclusionsDevelopment of an international COS will help to improve homogeneity of outcome measure reporting in NEC, will enable adequate and efficient comparison of treatment strategies, and will help the interpretation and implementation of clinical trial results. This will contribute to high-quality evidence regarding the best treatment strategy for NEC in preterm infants.

Novel mixed-method, inclusive protocol involving global key stakeholders, including carers as experts, to co-develop relevant Caregiver-Reported Outcome Domains (CRODs) in skin disease

IntroductionIchthyoses comprise a heterogenous group of rare genetic skin disorders that involves the entire skin surface, often with additional syndromic features, and pose many clinical challenges. Without curative intervention, the...

Developing a Core Outcome Set for Clinical Trials of Chinese Medicine for Hyperlipidemia.

Background: Chinese medicine (CM) is widely used for treating hyperlipidemias, especially in China. However, the heterogeneity of outcomes measured and reported across trials exacerbates the obstacles of evidence synthesis and effectiveness comparison. In this study, we develop a core outcome set (COS) for CM clinical trials for hyperlipidemia (COS-CM-Hyperlipidemia) to tackle the outcome issues. Methods: We generated candidate outcomes through a systematic review of interventional and observational studies of Chinese medicine for hyperlipidemias. The comprehensive search strategy was employed. Study selection and data collection were independently done by two researchers. We searched clinical trial registry platform to supplement the outcomes list extracted by systematic review. Then, we conducted a three-round Delphi survey. The stakeholders were hyperlipidemia patients, clinicians or researchers, in either CM/integrated Chinese or Western medicine, clinical pharmacy, clinical epidemiology or statisticians, or editors of important relevant journals and an ethicist. They used a 9-point Likert scale to determine how important they felt each outcome was in determining treatment success. A consensus meeting was held to confirm the final COS, based on the Delphi survey results. Results: We identified a total of 433 outcomes from 3,547 articles, and 28 outcomes from 367 registered trials. After standardization, we selected 71 outcomes to develop a preliminary outcome list for further consensus. After three Delphi survey rounds and one consensus meeting, the most important outcomes were determined for COS-CM-Hyperlipidemia. It included cardiovascular events, low-density lipoprotein cholesterol, risk of cardiovascular disease, total cholesterol, carotid intima-media thickness, high-density lipoprotein cholesterol, triglycerides, cerebrovascular events, adverse drug reactions and patient-reported symptoms. Conclusion: COS-CM-Hyperlipidemia may improve outcome reporting consistency in clinical trials. Further work is needed to explore the optimal methods for measuring these outcomes. Registration: The Core Outcome Measures in Effectiveness Trials Initiative (COMET): http://www.cometinitiative.org/studies/details/983. Registered on 25 April 2017.

Protocol for the development of a core outcome set for reporting outcomes of management of velopharyngeal dysfunction

IntroductionVelopharyngeal dysfunction (VPD) is present in up to 40% of patients following cleft palate repair. Children with VPD display hypernasal speech, nasal air emission and are at a high risk...

Developing an International Core Outcome Set for SSD Interventions

Developing an International Core Outcome Set for SSD Interventions

International development and implementation of a core measurement set for research and audit studies in implant-based breast reconstruction: a study protocol

IntroductionOutcome reporting in research studies of breast reconstruction is inconsistent and lacks standardisation. The results of individual studies therefore cannot be meaningfully compared or combined limiting their value. A core...

Core Health Outcomes in Childhood Epilepsy (CHOICE): Development of a core outcome set using systematic review methods and a Delphi survey consensus.

ObjectiveEstablishing a core set of outcomes to be evaluated and reported in intervention trials aims to improve the usefulness of health research. There is no established core outcome set (COS) for childhood epilepsies. The aim of this study was to select a COS to be used in evaluative research of interventions for children with rolandic epilepsy (RE).MethodsWe followed guidance from the COMET (Core Outcome Measures in Effectiveness Trials) Initiative. First, we identified outcomes that had been measured in research through a systematic review. Second, young people with RE, parents, and professionals were invited to take part in a Delphi survey in which participants rated the importance of candidate outcomes. Last, a face‐to‐face meeting was convened to seek consensus on which outcomes were critical to include and to ratify the final COS.ResultsFrom 37 eligible papers in the review, we identified and included 48 candidate outcomes in the survey. We sent invitations to 165 people registered to take part in the survey; of these, 102 (62%) completed Round 1, and 80 (78%) completed Round 2 (three young people, 16 parents, 61 professionals). In Round 2 we included four additional outcomes suggested by participants in Round 1. The consensus meeting included two young people, four parents, and nine professionals who were eligible to vote and ratified the COS as 39 outcomes across 10 domains.SignificanceOur methodology was a proportionate and pragmatic approach toward producing a COS for evaluating research on interventions aiming to improve the health of children with RE.

A core outcome set for clinical trials of Chinese medicine for hyperlipidemia: a study protocol for a systematic review and a Delphi survey

BackgroundHyperlipidemia, defined as elevated lipid levels, is the primary and major risk factor for atherosclerotic cardiovascular disease. Several studies have evaluated the effects of Chinese medicine (CM) on hyperlipidemia. However, due to the varied designs and methods of these studies, data synthesis has been difficult, restricting the practical value of the findings. Developing a core outcome set (COS) could solve these methodological concerns. In this paper, we report a protocol to develop a COS for CM clinical trials for hyperlipidemia (COS-CM-Hyperlipidemia).MethodsThe development of COS-CM-Hyperlipidemia will include four stages: (1) a systematic review to identify potential important outcomes—a study advisory group, composed of core stakeholders of hyperlipidemia, will be set up afterwards to evaluate the identified outcomes and a candidate outcome set will be developed accordingly; (2) a panel of experts will be invited to conduct a three-round Delphi survey, so that the experts’ opinions on the importance of outcomes for treating hyperlipidemia with CM will be collected; (3) a consensus meeting with clinicians, patients, and other key stakeholders will be conducted to finalize the items and definitions; and (4) COS-CM-Hyperlipidemia will be promoted and updated.DiscussionThe development of this COS will improve the design and operation of CM trials on hyperlipidemia, keeping them in compliance with international standards, as well as the comparability and utility of their results.Trial registrationThe Core Outcome Measures in Effectiveness Trials Initiative (COMET): http://www.comet-initiative.org/studies/details/983. Registered on 25 April 2017.

COMET VII MEETING REPORT

On the 15th and 16th November 2018, the Core Outcome Measures in Effectiveness Trials (COMET) Initiative held its seventh international meeting. After success at COMET VI, the COMET meeting returned to De Rode Hoed (The Red Hat) in Amsterdam for their second consecutive meeting. One-hundred and fifteen participants gathered from around the world, coming from five continents and 18 countries. COMET was awarded an MRC HTMR Impact Award to support the attendance of and participation of several researchers from low- and middle-income countries (LMIC) at COMET VII. Four participants successfully joined COMET VII, which included researchers from Brazil, India, and two different regions of Africa. COMET will work with these LMIC partners to develop a COMET strategy for further supporting the development, dissemination, and use of core outcome sets (COS) in LMICs. COMET VII consisted of a day and a half of plenary talks, contributed presentations, and workshops. Throughout the meeting, 45 posters created an opportunity for networking and stimulated discussion across a range of topics including (but not limited to): COS across the healthcare system, how to decide on the scope of a COS, how to measure outcomes in a COS, patient and public involvement and participation in COS, and COS uptake and implementation. These topics echoed the overall themes of the program, and speakers’ presentations can be viewed at http://www.comet-initiative.org/events/pastcomet. As in previous meetings, patient participation and involvement in COS development was a key feature of COMET VII. Along with a patient-focused workshop, there was a dedicated session that included an update from Rosemary Humphreys and Heather Bagley from the COMET People and Patient Participation Involvement and Engagement Working Group. They highlighted new resources including a video explaining what a COS is (http://www.comet-initiative.org/resources/PlainLanguageSummary), tips for designing an accessible COS consensus meeting, and research ethics considerations for COS studies with patients. All of these resources and more can be found at http://www.comet-initiative.org/ppi. The program was also interspersed with contributed talks that focused on patient participation, including methods for large international patient and public participation (Astrid Chevance, METHODS team, Center for Research in Epidemiology and Statistics, Paris) and a case study from the GRAPPA-OMERACT working group that described including patients in the process of outcome measurement tool selection (Maarten de Wit, OMERACT). Lucy Brading (University of Liverpool) presented thought-provoking results of interviews with COS patient research partners, as well as an ethnography study including 48 hours of observation. Results included a blurring of patient research partner and patient participant roles as well as developers’ aspirations to find the "right" patient research partner, often deemed to be a patient with previous PPI experience. Although PPI partners and researchers face distinctive challenges in their partnership to develop a COS, there is overriding opinion that their contribution is impactful. There is a current interest in identifying how COS might fit into the different stages of the healthcare research system. COMET VII provided a platform for relevant initiatives to start having a conversation about how they can support COS in and through the healthcare research system. The second session on day one focused on how different groups can influence and increase COS uptake reflecting the perspectives of Health Technology Assessment (HTA) agencies, clinical guideline developers, and trial/health research funders. With their proximity to reimbursement/coverage decisions, HTA bodies can increase awareness of COS, encourage COS development, and support uptake of COS. Relevant bodies have identified the potential challenge of different organizations’ requirements for condition-specific versus generic quality of life outcomes in COS. The second day of COMET VII started with a panel session with representatives of five relevant global initiatives: OMERACT (Peter Tugwell), CS-COUSIN (Jochen Schmitt), Sean Tunis (CMTP), ICHOM (Christina Akerman), and Robby Nieuwlaat (GRADE). This session stimulated discussion about the overlap and differences between these different initiatives. Although Sean Tunis described this group of representatives as a “smorgasbord of initiatives,” there was a clear willingness to keep communication open and work together in the future. COS may serve as a thread that pulls all the way through the healthcare research ecosystem, thus COMET VII was the ideal platform to initiate these discussions with relevant groups and individuals. Funding for the publication of the COMET VII conference proceedings was provided by the Journal of Evidence-based Medicine. Doug Altman (1948–2018), a founding member of COMET, passed away on Sunday 3 June 2018. Doug was brilliant, witty and generous. His family, friends, and many colleagues around the world will sorely miss him. It was an honor to have Doug on board the COMET Initiative and his work will long continue to inspire. Doug was remembered in a special session, led by Jamie Kirkham (University of Liverpool), at COMET VII.

Development of a core outcome set (COS) and selecting outcome measurement instruments (OMIs) for non-valvular atrial fibrillation in traditional Chinese medicine clinical trials: study protocol

BackgroundAn increasing number of clinical trials of traditional Chinese medicine are being conducted in the treatment of non-valvular atrial fibrillation (NVAF) in China. However, the heterogeneity of outcomes and outcome measurement instruments has produced little evidence for traditional Chinese medicine in treating NVAF because many trials cannot be included in a meta-analysis. The majority of the trials did not report endpoint outcomes, side effects or other important outcomes for patients, which makes it difficult to evaluate the efficacy and safety of traditional Chinese medicine. Therefore, it is important to develop a core outcome set (COS). Although there are two related COSs for clinical trials of atrial fibrillation, the methodology is limited, and the perspectives of Chinese experts and patients are unclear. Therefore, we will develop a COS and recommend outcome measurement instruments after finishing the COS, which can be used for clinical trials of traditional Chinese medicine in NVAF.Methods/designThe method of the study will include eight stages led by a national multidisciplinary Steering Committee: (1) A systematic review will be developed to identify currently reported outcomes and traditional Chinese medicine syndromes in clinical trials of NVAF, (2) Semi-structured interviews of patients will be conducted to fill gaps in potential outcomes, (3) Traditional Chinese medicine syndrome names will be identified from medical records, (4) A dataset of traditional Chinese medicine syndrome names will be developed, (5) The investigation of traditional Chinese medicine syndromes will be conducted from cross-sectional study, (6) Two rounds of Delphi surveys will be carried out, (7) A consensus meeting will be conducted to develop a COS, and (8) Recommendations of outcome measurement instruments (OMIs), which should be used in the COS, will be developed.DiscussionThe COS will improve the consistency of outcome reporting and reduce the reporting bias in NVAF clinical trials of traditional Chinese medicine to improve the value of traditional Chinese medicine clinical trials.Trial registrationThis study is not a clinical trial, so it is registered in Core Outcome Measures in Effectiveness Trials Initiative (COMET). Registration number: 941. Registered on 22 December 2016.

Developing a core outcome set for people living with dementia at home in their neighbourhoods and communities: study protocol for use in the evaluation of non-pharmacological community-based health and social care interventions

BackgroundThe key aim of the study is to establish an agreed standardised core outcome set (COS) for use when evaluating non-pharmacological health and social care interventions for people living at home with dementia.Methods/designDrawing on the guidance and approaches of the Core Outcome Measures in Effectiveness Trials (COMET), this study uses a four-phase mixed-methods design:Focus groups and interviews with key stakeholder groups (people living with dementia, care partners, relevant health and social care professionals, researchers and policymakers) and a review of the literature will be undertaken to build a long list of outcomes.Two rounds of Delphi surveys will be used with key stakeholder groups. Statements for the Delphi surveys and participation processes will be developed and informed through substantial member involvement with people living with dementia and care partners. A consensus meeting will be convened with key participant groups to discuss the key findings and finalise the COS.A systematic literature review will be undertaken to assess the properties of tools and instruments to assess components of the COS. Measurement properties, validity and reliability will be assessed using the Consensus-based Standards for the Selection of Health Measurement (COSMIN) and COMET guidance.A stated preference survey will elicit the preferences of key stakeholders for the outcomes identified as important to measure in the COS.DiscussionTo the best of our knowledge, this study is the first to use a modified Delphi process to involve people living with dementia as a participant group. Though the study is confined to collecting data in the United Kingdom, use of the COS by researchers will enhance the comparability of studies evaluating non-pharmacological and community-based interventions.Trial registrationThe study is registered on the COMET initiative, registered in 2014 at comet-initiative.org.

Choosing important health outcomes for comparative effectiveness research: An updated systematic review and involvement of low and middle income countries.

BackgroundCore outcome sets (COS) comprise a minimum set of outcomes that should be measured and reported in all trials for a specific health condition. The COMET (Core Outcome Measures in Effectiveness Trials) Initiative maintains an up to date, publicly accessible online database of published and ongoing COS. An annual systematic review update is an important part of this process.MethodsThis review employed the same, multifaceted approach that was used in the original review and the previous two updates. This approach has identified studies that sought to determine which outcomes/domains to measure in clinical trials of a specific condition. This update includes an analysis of the inclusion of participants from low and middle income countries (LMICs) as identified by the OECD, in these COS.ResultsEighteen publications, relating to 15 new studies describing the development of 15 COS, were eligible for inclusion in the review. Results show an increase in the use of mixed methods, including Delphi surveys. Clinical experts remain the most common stakeholder group involved. Overall, only 16% of the 259 COS studies published up to the end of 2016 have included participants from LMICs.ConclusionThis review highlights opportunities for greater public participation in COS development and the involvement of stakeholders from a wider range of geographical settings, in particular LMICs.

Choosing Important Health Outcomes for Comparative Effectiveness Research: An Updated Review and Identification of Gaps.

BackgroundThe COMET (Core Outcome Measures in Effectiveness Trials) Initiative promotes the development and application of core outcome sets (COS), including relevant studies in an online database. In order to keep the database current, an annual search of the literature is undertaken. This study aimed to update a previous systematic review, in order to identify any further studies where a COS has been developed. Furthermore, no prioritization for COS development has previously been undertaken, therefore this study also aimed to identify COS relevant to the world’s most prevalent health conditions.MethodsThe methods used in this updated review followed the same approach used in the original review and the previous update. A survey was also sent to the corresponding authors of COS identified for inclusion in this review, to ascertain what lessons they had learnt from developing their COS. Additionally, the COMET database was searched to identify COS that might be relevant to the conditions with the highest global prevalence.ResultsTwenty-five reports relating to 22 new studies were eligible for inclusion in the review. Further improvements were identified in relation to the description of the scope of the COS, use of the Delphi technique, and the inclusion of patient participants within the development process. Additionally, 33 published and ongoing COS were identified for 13 of the world’s most prevalent conditions.ConclusionThe development of a reporting guideline and minimum standards should contribute towards future improvements in development and reporting of COS. This study has also described a first approach to identifying gaps in existing COS, and to priority setting in this area. Important gaps have been identified, on the basis of global burden of disease, and the development and application of COS in these areas should be considered a priority.

Choosing Important Health Outcomes for Comparative Effectiveness Research: An Updated Review and User Survey.

BackgroundA COS represents an agreed minimum set of outcomes that should be measured and reported in all trials of a specific condition. The COMET (Core Outcome Measures in Effectiveness Trials) initiative aims to collate and stimulate the development and application of COS, by including data on relevant studies within a publically available internet-based resource. In recent years, there has been an interest in increasing the development of COS. Therefore, this study aimed to provide an update of a previous review, and examine the quality of development of COS. A further aim was to understand the reasons why individuals are searching the COMET database.MethodsA multi-faceted search strategy was followed, in order to identify studies that sought to determine which outcomes/domains to measure in clinical trials of a specific condition. Additionally, a pop up survey was added to the COMET website, to ascertain why people were searching the COMET database.ResultsThirty-two reports relating to 29 studies were eligible for inclusion in the review. There has been an improvement in the description of the scope of a COS and an increase in the proportion of studies using literature/systematic reviews and the Delphi technique. Clinical experts continue to be the most common group involved in developing COS, however patient and public involvement has increased. The pop-up survey revealed the most common reasons for visiting the COMET website to be thinking about developing a COS and planning a clinical trial.ConclusionsThis update demonstrates that recent studies appear to have adopted a more structured approach towards COS development and public representation has increased. However, there remains a need for developers to adequately describe details about the scope of COS, and for greater public engagement. The COMET database appears to be a useful resource for both COS developers and users of COS.

Choosing important health outcomes for comparative effectiveness research: an updated review and user survey

Background A COS represents an agreed minimum set of outcomes that should be measured and reported in all trials of a specific condition. The COMET (Core Outcome Measures in Effectiveness Trials) initiative aims to collate and stimulate the development and application of COS, by including data on relevant studies within a publically available internet-based resource. In recent years, there has been an interest in increasing the development of COS. Therefore, this study aimed to provide an update of a previous review, and examine the quality of development of COS. A further aim was to understand the reasons why individuals are searching the COMET database.

The core outcome measures in effectiveness trials (COMET) initiative: five years on

Core outcome sets (COS) can reduce waste in research, through measurement of an agreed set of outcomes across all trials in a particular area of health. The COMET Initiative was launched in 2010 to (i) raise awareness of problems with outcomes in trials; (ii) encourage COS development and uptake; (iii) promote patient and public involvement in COS development; (iv) provide resources to facilitate this; and (v) encourage evidence-based COS development. This talk will review progress and challenges over our first five years. It will describe our work with multiple stakeholders to facilitate engagement, including funders, trialists, patient organisations, systematic reviewers, editors, industry, regulators, and guideline developers. The perception that COMET was a ‘UK thing’ has been dispelled, with the establishment of an International Advisory Group and meetings in Rome (2014) and Calgary (2015). Highlights include the development of a searchable repository of COS studies, and completion of the first comprehensive systematic review of published COS (recently updated to December 2014). Over 7800 searches have been done of the online repository, most visitors in 2014 were from outside the UK and we will present findings from a pop-up survey of why people search it. Promoting broader uptake of COS by researchers and securing funding for initiatives aimed at reducing waste in research remain major challenges. As awareness of the need for COS continues to grow and knowledge of the COMET Initiative increases, this is an appropriate moment to present our future proposals, including a research agenda, to the trials methodology community.

Collating the knowledge base for core outcome set development: developing and appraising the search strategy for a systematic review.

BackgroundThe COMET (Core Outcome Measures in Effectiveness Trials) Initiative is developing a publicly accessible online resource to collate the knowledge base for core outcome set development (COS) and the applied work from different health conditions. Ensuring that the database is as comprehensive as possible and keeping it up to date are key to its value for users. This requires the development and application of an optimal, multi-faceted search strategy to identify relevant material. This paper describes the challenges of designing and implementing such a search, outlining the development of the search strategy for studies of COS development, and, in turn, the process for establishing a database of COS.MethodsWe investigated the performance characteristics of this strategy including sensitivity, precision and numbers needed to read. We compared the contribution of databases towards identifying included studies to identify the best combination of methods to retrieve all included studies.ResultsRecall of the search strategies ranged from 4% to 87%, and precision from 0.77% to 1.13%. MEDLINE performed best in terms of recall, retrieving 216 (87%) of the 250 included records, followed by Scopus (44%). The Cochrane Methodology Register found just 4% of the included records. MEDLINE was also the database with the highest precision. The number needed to read varied between 89 (MEDLINE) and 130 (SCOPUS).ConclusionsWe found that two databases and hand searching were required to locate all of the studies in this review. MEDLINE alone retrieved 87% of the included studies, but actually 97% of the included studies were indexed on MEDLINE. The Cochrane Methodology Register did not contribute any records that were not found in the other databases, and will not be included in our future searches to identify studies developing COS. SCOPUS had the lowest precision rate (0.77) and highest number needed to read (130). In future COMET searches for COS a balance needs to be struck between the work involved in screening large numbers of records, the frequency of the searching and the likelihood that eligible studies will be identified by means other than the database searches.Electronic supplementary materialThe online version of this article (doi:10.1186/s12874-015-0019-9) contains supplementary material, which is available to authorized users.

Core outcome sets will improve the quality of obstetrics research

Anyone who has ever tried to make sense of the medical literature as a systematic reviewer, a clinical trialist, a clinician, or a patient will likely recognise the problem so elegantly demonstrated by Meher and Alfirevic. They have shown that variability in both what to measure, for example length of gestation or perinatal morbidity, and how to measure, for example defining necrotising enterocolitis, leads to difficulty in summarising the evidence for interventions for preterm birth prevention. The effect is to limit the contribution to advancing the usefulness of research in informing clinical practice and empowering patients with information to make decisions about interventions. As the authors suggest, a solution to this problem is the development of a core outcome set. This is a minimum set of agreed standardised outcomes that would be measured and reported in all trials in a specific condition. It then follows that this same set would be relevant for the systematic reviews of those trials. The advantage in terms of combining and contrasting results from different studies if they all measured key outcomes is obvious. The most established core outcome set, developed for rheumatoid arthritis, is now measured and reported in nearly three-quarters of studies (Kirkham et al. Trials 2013;14:324). Resources to support core outcome set development are being brought together in the Core Outcome Measures in Effectiveness Trials (COMET) initiative (www.cometinitiative.org). COMET provides a publically available searchable database of published and continuing core outcome set work, soon to be supplemented by the results from a systematic review of over 25 000 papers. This is a unique resource, which will be updated periodically, and should serve to minimise unnecessary duplication. Various methods have been used to develop core outcome sets, but there is limited empirical evidence regarding whether different methods lead to similar or different conclusions. Key issues to consider have been proposed (Williamson et al. Trials 2012;13:132), and include: (1) defining the scope of the healthcare area that the set will apply to, in terms of health condition, population, and types of interventions; (2) identifying existing knowledge, including reviews of previous trials, such as that undertaken by Meher and Alfirevic; (3) choice of method for determining consensus; and (4) determining who the key groups are to involve. As Meher and Alfirevic note, it is ‘important that RCTs and systematic reviews measure end points that are relevant and meaningful to patients, clinicians, and health service providers'. Although the original core outcome set for rheumatoid arthritis was developed by clinicians alone, patients have subsequently been asked which outcomes are most important to them. They identified fatigue, an outcome not previously included in the set. COMET aims to foster methodological research into core outcome set development, including how best to engage patients in this work, and to encourage the publication of study protocols (e.g. Harman et al. Trials 2013;14:70). In conclusion, the adoption of core outcome sets has the potential to increase the consistency in outcomes measured across trials, and to ensure that trials are more likely to measure appropriate outcomes. Paula Williamson chairs the Management Group of the COMET initiative.