Feasibility, Reliability, Responsiveness, and Validity of the Patient-Reported Functional Scale for the Intensive Care Unit: A Pilot Study.

ABSTRACT

BACKGROUND: Although many performance-based measures assess patients' physical function in intensive care unit (ICU) survivors, to our knowledge, there are no patient-reported ICU rehabilitation-specific measures assessing function. We developed the Patient-Reported Functional Scale-ICU (PRFS-ICU), which measures patients' perceptions of their ability to perform 6 activities (rolling, sitting edge of bed, sit-to-stand and bed-to-chair transfers, ambulation, and stair climbing). Each item is scored from 0 (unable) to 10 (able to perform at pre-ICU level) to a maximum of 60. OBJECTIVES: Estimate the feasibility, reliability, responsiveness, and validity of the PRFS-ICU. METHODS: This was a substudy of TryCYCLE, a single-center, prospective cohort examining the safety and feasibility of early in-bed cycling with mechanically ventilated patients (NCT01885442). To determine feasibility, we calculated the number of patients with at least 1 PRFS-ICU assessment during their hospital stay. To assess reliability, 2 raters blinded to each other's assessments administered the PRFS-ICU within 24-hours of each other. We calculated the intraclass correlation coefficient (ICC; 95% confidence interval [CI]), standard error of measurement (SEM, 95% CI), and minimal detectable change (MDC90). To assess validity, we estimated convergent validity of the PRFS-ICU with the Functional Status Score for ICU (FSS-ICU), Medical Research Council Sum Score (MRC-SS), Physical Function Test for ICU (PFIT-s), Katz Index of Independence in Activities of Daily Living (Katz ADLs), and a pooled index using Pearson's correlation coefficient (r, 95% CI). RESULTS: Feasibility 20 patients completed a PRFS-ICU assessment. Reliability and responsiveness 16 patients contributed data. The ICC, SEM, and MDC90 were 0.91 (0.76, 0.97), 4.75 (3.51, 7.35), and 11.04 points, respectively. Validity 19 patients contributed data and correlations were (r [95% CI]) FSS-ICU (0.40 [-0.14, 0.76]), MRC-SS (0.51 [0.02, 0.80]), PFIT-s (0.43 [-0.13, 0.78]), Katz ADLs (0.53 [0.10, 0.79]), and pooled index (0.48 [-0.14, 0.82]). CONCLUSIONS: Our pilot work suggests the PRFS-ICU may be a useful tool to assess and monitor patients' perceptions of function over time.