VALIDATION DATA

MEASUREMENT PROPERTIES
Limitations >=5 European languages (English)
Observations
1. RELIABILITY
A. Internal Consistency Not Tested
Cronbach's (Describe)
B. Reliability intraobserver or test-retest Tested
Continuous scores: intraclass
correlation coefficient (ICC)
Dichotomus: Cohen kappa (Describe)

The test-retest reliability of the PSFS has been assessed in different studies on MSCs, resulting in ICCs between 0.71 and 0.97

C. Reliability interobserver or Measurement error Not Tested
Standard error of measurement (SEM),
smallest detectable change (SDC) or
Limits of agreement (LoA) (Describe)
2. VALIDITY
A. Content validity: face validity Not Tested
Expert opinion (relevance and
comprehensiveness) (Describe)
B. Construct Validity:
Structural validity
Tested
Hypotheses-testing Tested
Cross-cultural validity Not Tested
Brief Description

Paired-samples t-tests demonstrated that the mean change score was consistent, with 0 in the stable group, and significantly different from 0 (in the appropriate direction) in the improved group. Independent-samples t-tests demonstrated a significant difference in mean change between the stable and improved groups. Differences for all outcome measures were highly significant (P < 0.001), providing evidence of the construct validity of the PSFS.

C. Criterion validity Not Tested
Comparison with a 'gold standard' Continuous scores:
correlations, ROC curves Dichotomus:
Sensitivity & Specificity (Describe)