How to select outcome measurement instruments for outcomes included in a “Core Outcome Set” – a practical guideline

Cecilia A C Prinsen,Caroline B Terwee,Maarten Boers,Michael R Rose,Mike Clarke,Peter Tugwell,Sunita Vohra,Paula R Williamson

doi:10.1186/s13063-016-1555-2

Abstract

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.

Highlights

In 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 included in a “Core Outcome Set” (COS)
We proposed the following recommendation for the guideline: “It is recommended that, in case no face validity assessment is reported in the literature, COS developers assess the face validity of an Outcome Measurement Instrument (OMI) to be included in a COS.”
A consensus procedure to agree on the outcome measurement instruments for each outcome included in 90 a COS should be performed among all relevant stakeholders, including patients aSee Table 3 for the percentage of agreement per measurement property separately bSee Table 6 for the percentage of agreement per feasibility aspect separately c“High quality evidence” is defined as consistent findings in multiple studies of at least good quality OR in one study of excellent quality AND a total sample size of 100 patients or more (Table 5) d“Good” is defined as a “+” rating according to the criteria for good measurement properties (Table 4)

Summary

Introduction

In 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). The current project is a joint initiative between the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) initiative [4] and the Core Outcome Measures in Effectiveness Trials (COMET) initiative [5]. 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. It is a recommendation of what should be measured and reported in all clinical trials [7]

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Conclusion