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CPAx: Responsiveness and Minimal Clinically Important Difference

Recruiting
Conditions
Muscle Weakness
Physical Inactivity
Critical Illness Polyneuropathy
Critical Illness Polyneuromyopathy
Critical Illness Myopathy
Registration Number
NCT06419699
Lead Sponsor
Insel Gruppe AG, University Hospital Bern
Brief Summary

Intensive care unit (ICU) acquired weakness is a common complication associated with long-term physical impairments in survivors of a critical illness. The Chelsea Critical Care Physical Assessment tool (CPAx) is a valid and reliable instrument for physical function and activity in critically ill patients at risk for muscle weakness. However, its ability to measure change over time (responsiveness) and the minimal clinically important difference (MCID) have not yet been rigorously investigated. This multi-centre, mixed-methods, longitudinal cohort study therefore aims to establish responsiveness and the MCID of the CPAx in the target population from ICU baseline to ICU and hospital discharge. The study uses routine data from standard physiotherapy sessions like mobility, function and activity with no additional burden for critically ill adults. The investigators expect the CPAx to be responsive allowing its use as a primary outcome in future effectiveness trials for the treatment of ICU-acquired weakness using the newly established MCID for sample size calculation. A high quality, rigorously tested measurement tool for physical function and activity in the ICU should benefit researchers, clinicians and patients.

Detailed Description

The use of invasive life support in critically ill patients clearly saves lives but carries substantial risks, including intensive care unit (ICU) acquired weakness and long-term disability. The investigators urgently need a valid, reliable, and responsive measurement tool for this population to use in clinical practice and trials. The Chelsea Critical Care Physical Assessment tool (CPAx) is a promising measurement instrument to measure change in critically ill patients' physical function and activity. After several studies have confirmed its validity and excellent reliability, it is time to confirm responsiveness and to establish the MCID in a large, international sample of the target population. This multi-centre, mixed-methods, longitudinal cohort study will include critically ill, mechanically ventilated (\>72h) adults at risk for muscle weakness and collect their mobility, physical function and activity with the CPAx and other relevant measures at ICU baseline, to ICU and hospital discharge. Responsiveness will be determined by the ability of the CPAx to identify change according to a prespecified anchor (criterion validity) and by testing prospective hypotheses about the expected magnitude of change between the CPAx and other relevant measures (construct validity). The MCID will be established with anchor- and distribution-based methods, whereby a seven-point global rating of change scale obtained from treating ICU physiotherapists will serve as anchor to distinguish improved from unchanged patients.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
120
Inclusion Criteria
  • Age ≥ 18 years
  • Mechanical ventilation ≥ 72 hours
  • Expected to remain for ≥ 48 hours in the ICU
  • Physiotherapy referral
Exclusion Criteria
  • Not expected to survive to hospital discharge (imminent to death)
  • Second or subsequent ICU admission for this hospital stay
  • Transfer from external ICU (with an ICU stay of >72 hours)
  • Primary neurological admission diagnosis (i.e., of the central nervous system including stroke, intracerebral haemorrhage, traumatic brain injury)
  • Known pregnancy
  • Living in a care facility pre-admission (severe pre-existing mental or physical disability)
  • Local regulations (i.e. Switzerland: refusal of general consent)

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
Chelsea Critical Care Physical Assessment tool (CPAx) change scoreAssessed at ICU discharge (within 24 hours before or after ICU discharge)

CPAx change score for ICU period (ICU baseline to ICU discharge); CPAx ranges from 0 (worst score) to 50 (best score)

Secondary Outcome Measures
NameTimeMethod
Medical Research Council Sum ScoreICU baseline (within 72-144h after ICU admission), ICU and hospital discharge

To assess muscle strength, the minimal score is 0 (worst), the maximal score 60 (best), ICUAW is defined as \<48 points

Modified Iowa Level of Assistance ScaleICU baseline (within 72-144h after ICU admission), ICU and hospital discharge

To determine assistance in functional tasks, the score ranges from 0 (worst) to 36 (best)

CPAx change scoreAssessed at hospital discharge (last value before discharge)

CPAx change score for hospital period (ICU to hospital discharge); CPAx ranges from 0 (worst score) to 50 (best score)

Global rating of change scaleICU and hospital discharge (change for ICU and hospital period)

Seven-point global rating of change scale (GRC): (1) very much improved; (2) much improved; (3) little improved; (4) no change; (5) little deterioration; (6) much deterioration; (7) very much deterioration for 'physical function and activity' (rated by treating physiotherapist)

Richmond Agitation-Sedation ScaleICU baseline (within 72-144h after ICU admission), ICU and hospital discharge

To assess the level of sedation and/or cooperation, score ranges from -5 (unarousable) to +4 (combative)

ICU Mobility ScaleICU baseline (within 72-144h after ICU admission), ICU and hospital discharge

To evaluate mobility level, the score ranges from 0 (worst) to 10 (best)

ICU and discharge destinationsICU and hospital discharge

Categorical variable (death, external/internal hospital ward, external ICU/hospital, rehabilitation, home, other) to assess the predictive validity of the CPAx score

Trial Locations

Locations (3)

Monash Health

🇦🇺

Clayton, Australia

Alfred Health

🇦🇺

Melbourne, Australia

Inselspital

🇨🇭

Bern, Switzerland

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