Core Outcome Measures for Clinical Research in Acute Respiratory Failure Survivors. An International Modified Delphi Consensus Study

Abstract

Rationale: Research evaluating acute respiratory failure (ARF) survivors' outcomes after hospital discharge has substantial heterogeneity in terms of the measurement instruments used, creating barriers to synthesizing study data.

Objectives: To identify a minimum set of core outcome measures that are essential to include in all clinical research studies evaluating ARF survivors after discharge.

Methods: We conducted a three-round modified Delphi consensus process with 77 participants (47% female, 55% outside the United States), including clinical researchers from more than 16 countries across six continents, patients/caregivers, clinicians, and research funders. Participants reviewed standardized information on measure instruments for seven consensus-derived outcomes plus one recommended outcome.

Measurements and main results: Response rates were 91 to 97% across the three rounds. Among 75 measurement instruments evaluated, the following met a priori consensus criteria: EQ-5D and 36-item Short Form Health Survey version 2 (optional) for the "satisfaction with life and personal enjoyment" and "pain" outcomes, and both the Hospital Anxiety and Depression Scale and the Impact of Events Scale-Revised for the "mental health" outcome. No measures reached consensus for the following outcomes: cognition, muscle and/or nerve function, physical function, and pulmonary function. All measures considered for pulmonary function met consensus criteria for exclusion. The following measures did not reach the threshold for consensus but achieved the highest scores for their respective outcomes: the Montreal Cognitive Assessment (cognition), manual muscle testing and handgrip dynamometry (muscle and/or nerve function), and 6-minute-walk test (physical function).

Conclusions: This Core Outcome Measurement Set is recommended for use in all clinical research evaluating ARF survivors after hospital discharge. In the future, researchers should evaluate measures for outcomes not reaching consensus.

Keywords: Core Outcome Measurement Set; clinical trials; follow-up studies; intensive care; patient outcome assessment.

Figures

Figure 1.

Flow diagram for modified Delphi consensus process. 1Of 76 experts invited, 2 patients/caregivers declined to participate, and one was replaced. Of 75 participants, there was a nonresponse from 1 clinical researcher and 1 patient/caregiver in round 1; 2 clinical researchers and 5 patients/caregivers in round 2, and 3 patients/caregivers in round 3. 2Consensus criteria for including a measure in the Core Outcome Measurement Set: ≥70% of responses rate the measure “Critical” (i.e., score ≥ 7) and ≤15% of responses rate the measure “Not Important” (i.e., score ≤ 3). 3Consensus criteria for excluding from the Core Outcome Measurement Set: >15% of responses rated the measure “Not Important” (i.e., score ≤ 3).

Figure 2.

Future research agenda for improving outcome measurement in acute respiratory failure survivors. EQ-5D-5L = EQ-5D five-level version.