Development of a core outcome set for trials of physical rehabilitation after critical illness

Muscle wasting and weakness are characteristic in patients following critical illness and are significant drivers underlying physical impairment in survivors. Previous data have reported a 20% reduction in muscle bulk observed in intensive care unit (ICU) patients within the first ten days of admission and this effect is more pronounced in those with multi-organ failure. Observational follow-up of survivors of critical illness has demonstrated deficits in exercise capacity, physical function and health-related quality of life related to physical activity persisting up to five years post index ICU admission. In recent years, the profile, importance and research activity surrounding physical rehabilitation delivered to patients post critical illness has increased. Trials of interventions have been undertaken at each stage of the patient recovery pathway - within the ICU, following transfer to the ward and post hospital discharge. However there is currently no consensus on outcome selection, definition, measurement and reporting for evaluation of interventions limiting synthesis and meta-analyses of data from existing trials. Consensus on a core outcome set (COS) i.e. an agreed, standardised minimum collection of outcomes, has many potential advantages - to facilitate comparison across multiple datasets, reduce selective outcome reporting bias and promote consistency across trials, enhance evidence synthesis through maximum inclusion of studies into meta-analyses, and determine the outcomes of value for key stakeholders including those who may have previously been under-represented e.g. patients.

1. To characterise selection and definition of outcomes used in existing trials of physical rehabilitation after critical illness
2. To obtain consensus on a COS for future trials of physical rehabilitation
following critical illness delivered across the recovery continuum (within ICU, post ICU discharge and post hospital discharge)



Principal Investigator
Dr Bronwen Connolly
Guy’s and St.Thomas’ NHS Foundation Trust,
King’s College London

Dr Bronagh Blackwood
Queen’s University Belfast

Dr Nicholas Hart
Guy’s and St.Thomas’ NHS Foundation Trust,
King’s College London

Prof Paula Williamson
University of Liverpool

Further Study Information

Current Stage: Completed – pending publication
Date: May 2013 - May 2017
Funding source(s): National Institute of Health Research, United Kingdom PDF-2015-08-015

Health Area

Disease Category: Other

Disease Name: Critical illness

Target Population

Age Range: 16 - 100

Sex: Either

Nature of Intervention: Rehabilitation, Exercise, Physical

Stakeholders Involved

- Clinical experts
- Funders
- Guideline developers
- Researchers
- Service commissioners
- Service users

Study Type

- Systematic review of outcomes measured in trials
- COS for clinical trials or clinical research


- Delphi process
- Systematic review
- Consensus conference
- Focus group(s)

Phase 1
A systematic review of outcome reporting from existing trial evidence of physical rehabilitation after critical illness, including interventions delivered at any stage of the recovery pathway. Metrics of outcomes will be reported and synthesised including definition and detail of primary and secondary outcomes, measurement variables, analysis metrics, method of aggregation, time-point of measurement and classification of the outcome
according to the World Health Organisation International Classification of Impairment, Disability and Health model.

Phase 2
A two-stage Delphi process to firstly establish stakeholder consensus on core outcomes considered priority for future rehabilitation trials and secondly determine outcome measurement instrument selection. The findings of the systematic review from Phase 1 will form the basis of this consensus. Stakeholders will include international interdisciplinary expert clinicians, researchers, relevant patient/relatives bodies, and those from policy-making organisations and funding streams. A bespoke electronic online software will be developed for conduct of the Delphi process.