BackgroundIn cooperation with the Core Outcome Measures in Effectiveness Trials (COMET) initiative, the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) initiative aimed to develop a guideline on how to select outcome measurement instruments for outcomes (i.e., constructs or domains) included in a “Core Outcome Set” (COS). A COS is an agreed minimum set of outcomes that should be measured and reported in all clinical trials of a specific disease or trial population.MethodsInformed by a literature review to identify potentially relevant tasks on outcome measurement instrument selection, a Delphi study was performed among a panel of international experts, representing diverse stakeholders. In three consecutive rounds, panelists were asked to rate the importance of different tasks in the selection of outcome measurement instruments, to justify their choices, and to add other relevant tasks. Consensus was defined as being achieved when 70 % or more of the panelists agreed and when fewer than 15 % of the panelists disagreed.ResultsOf the 481 invited experts, 120 agreed to participate of whom 95 (79 %) completed the first Delphi questionnaire. We reached consensus on four main steps in the selection of outcome measurement instruments for COS: Step 1, conceptual considerations; Step 2, finding existing outcome measurement instruments, by means of a systematic review and/or a literature search; Step 3, quality assessment of outcome measurement instruments, by means of the evaluation of the measurement properties and feasibility aspects of outcome measurement instruments; and Step 4, generic recommendations on the selection of outcome measurement instruments for outcomes included in a COS (consensus ranged from 70 to 99 %).ConclusionsThis study resulted in a consensus-based guideline on the methods for selecting outcome measurement instruments for outcomes included in a COS. This guideline can be used by COS developers in defining how to measure core outcomes.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1555-2) contains supplementary material, which is available to authorized users.

No abstract

Objective To conduct a systematic review of the efficacy and safety of exogenous melatonin in managing secondary sleep disorders and sleep disorders accompanying sleep restriction, such as jet lag and shiftwork disorder. Data sources 13 electronic databases and reference lists of relevant reviews and included studies; Associated Professional Sleep Society abstracts (1999 to 2003). Study selection The efficacy review included randomised controlled trials; the safety review included randomised and non-randomised controlled trials. Quality assessment Randomised controlled trials were assessed by using the Jadad Scale and criteria by Schulz et al, and non-randomised controlled trials by the Downs and Black checklist. Data extraction and synthesis One reviewer extracted data and another reviewer verified the data extracted. The inverse variance method was used to weight studies and the random effects model was used to analyse data. Main results Six randomised controlled trials with 97 participants showed no evidence that melatonin had an effect on sleep onset latency in people with secondary sleep disorders (weighted mean difference − 13.2 (95% confidence interval − 27.3 to 0.9) min). Nine randomised controlled trials with 427 participants showed no evidence that melatonin had an effect on sleep onset latency in people who had sleep disorders accompanying sleep restriction ( − 1.0 ( − 2.3 to 0.3) min). 17 randomised controlled trials with 651 participants showed no evidence of adverse effects of melatonin with short term use (three months or less). Conclusions There is no evidence that melatonin is effective in treating secondary sleep disorders or sleep disorders accompanying sleep restriction, such as jet lag and shiftwork disorder. There is evidence that melatonin is safe with short term use.

BackgroundThe Core Outcome Measures in Effectiveness Trials (COMET) initiative aims to facilitate the development and application of ‘core outcome sets’ (COS). A COS is an agreed minimum set of outcomes that should be measured and reported in all clinical trials of a specific disease or trial population. The overall aim of the Core Outcome Measurement Instrument Selection (COMIS) project is to develop a guideline on how to select outcome measurement instruments for outcomes included in a COS. As part of this project, we describe our current efforts to achieve a consensus on the methods for selecting outcome measurement instruments for outcomes to be included in a COS.Methods/DesignA Delphi study is being performed by a panel of international experts representing diverse stakeholders with the intention that this will result in a guideline for outcome measurement instrument selection. Informed by a literature review, a Delphi questionnaire was developed to identify potentially relevant tasks on instrument selection. The Delphi study takes place in a series of rounds. In the first round, panelists were asked to rate the importance of different tasks in the selection of outcome measurement instruments. They were encouraged to justify their choices and to add other relevant tasks. Consensus was reached if at least 70% of the panelists considered a task ‘highly recommended’ or ‘desirable’ and if no opposing arguments were provided. These tasks will be included in the guideline. Tasks that at least 50% of the panelists considered ‘not relevant’ will be excluded from the guideline. Tasks that were indeterminate will be taken to the second round. All responses of the first round are currently being aggregated and will be fed back to panelists in the second round. A third round will only be performed if the results of the second round require it.DiscussionSince the Delphi method allows a large group of international experts to participate, we consider it to be the preferred consensus-based method for our study. Based upon this consultation process, a guideline will be developed on instrument selection for outcomes to be included in a COS.