Following recruitment all participants will be assessed by a medical doctor or respiratory therapist (trained on the study) who will fill out the MIND questionnaire on admission and make sure the other scales/questionnaires are also completed. On the same day of the collection of MIND, MRC score for quadriceps and biceps strength, Sequential Organ Failure Assessment (SOFA) score, Glasgow coma scale, Hospital Anxiety-depression scale (HADS), EuroQol-5D, Gussago Dependence Nursing Scale (GNS) will be also gathered. After 1 day and 30 days the MIND questionnaire will be also evaluated. Index of ADL-(Katz index) will be evaluated on discharge as well as weaning rate and survival.
Sample Size Determination
Based on the method of Rouquette A et al (1) we estimated a sample size of 200 patients to allow for the Rasch modelling to be applied.
Statistical analysis
Assessment of construct validity:
Confirmation of the structure (e.g. multitrait analysis), clinical validity (comparison of disability score according to external clinical criteria)
Assessment of reliability:
Internal consistency reliability (using Cronbach's alpha), test-retest reliability (using intraclass correlations)
Assessment of sensitivity to change over time:
Comparison of change in disability score according to change in external clinical criteria Guidance for interpretation of disability score: Estimation of thresholds for patients' classification
1-Rouquette A, Falissard B Sample size requirements for the internal validation of psychiatric scales Int J Methods Psychiatr Res. 2011 Dec;20(4):235-49. doi: 10.1002/mpr.352. Epub 2011 Oct 24.
