Table 1.
Summary of measurement properties of physical functioning instruments for the ICU
| Instrument name (range for score) | Evidence of reliability? | Evidence of validity? | Evidence of predictive validity? | Evidence of responsiveness? | Evidence for MID? | Evaluation of floor and ceiling effects?# |
|---|---|---|---|---|---|---|
| ACIF (0–1) | Yes | Construct validity: Yes | Yes: for discharge to home | No | No | Low floor and ceiling in ICU |
| CPAx (0–50) | Yes | Content validity: Yes Construct validity: Yes |
Yes: for discharge to home | Yesa | Yesa | High floor at ICU admission; Low floor and ceiling at ICU and hospital dischargea |
| CcFROM (0–63) | Yes | Face/content validity: Yes | No | No | No | Low floor and ceiling in ICU |
| DEMMI (0–100) | Yes | Convergent validity: Yes Divergent validity: Yes |
No | No | No | Low floor and ceiling in ICU |
| FSS-ICU (0–35) | Yes | Construct validity: Yes Discriminant validity: Yes Known groups validity: Yes |
Yes: for discharge to home and post-ICU hospital LOSb | Yes | Yes | Low floor and ceiling at awakening and ICU discharge, high ceiling at hospital discharge |
| IMS (0–10) | Yes | Construct validity: Yes Divergent validity: Yes |
Yes: for discharge to home and 90-day survivalb | Yes | No | High floor at ICU admission; Low floor and ceiling at ICU awakening and ICU discharge |
| MMS (0–7) | Yes | Construct validity: Yes | Yes: for post-ICU hospital LOS | No | No | High floor during ICU stay |
| Perme (0–32) | Yes | Construct validity: Yes | No | No | No | High floor during ICU stay |
| PFIT-s (0–10) | Yes | Construct validity: Yes Divergent validity: Yes |
Yes: for discharge to home, post-ICU hospital LOS; Not predictive of 28-day and 12-month mortalityc | Yes | Yes | High floor at ICU admission; Low floor and ceiling at awakening and ICU discharge |
| SOMS (0–4) | Yes | Construct validity: Yes Divergent validity: Yes |
Yes: for ICU and hospital LOS, and in-hospital mortalityd | No | No | Low floor and ceiling at ICU admission |
| SPPB (0–12) | No | Construct validity: Yes Divergent validity: Yes |
Not predictive of discharge to homeb | Yes | Yes | High floor at awakening and ICU discharge |
#A low floor and ceiling effect is necessary. A low floor/ceiling effect was defined as <15%, and high floor/ceiling effect as >15% at any time point [26]
aThe MID has only been reported within the burns population for the CPAx; floor and ceiling effects have mainly been reported for the burns population. At ICU discharge the floor and ceiling effect was 13% and 0% in the burns population versus a floor and ceiling effect of 3% and 1% in a general ICU population
bPredictive validity for FSS-ICU, IMS, and SPPB were evaluated from ICU discharge physical functioning scores
cPredictive validity for PFIT-s were evaluated from ICU admission (scores evaluated a median of 6 days (range 5–9 days) after admission for all patient outcomes except discharge to home which has been evaluated across three time points: ICU admission, ICU awakening, and ICU discharge)
dPredictive validity for SOMS was evaluated from baseline ICU admission scores
ACIF Acute Care Index of Function, CPAx Chelsea Critical Care Physical Assessment Tool, CcFROM Critical Care Functional Rehabilitation Outcome Measure, DEMMI De Morton Mobility Index, FSS-ICU Functional Status Score for the ICU, ICU intensive care unit, IMS ICU mobility scale, LOS length of stay, MID minimal important difference, MMS, Perme Perme ICU Mobility Score, PFIT-s Physical Function in intensive care test scored, SOMS Surgical Optimal Mobility Scale, SPPB Short Physical Performance Battery, MMS Manchester Mobility Score