VALIDATION DATA

MEASUREMENT PROPERTIES
Limitations <5 European languages (English)
Observations
1. RELIABILITY
A. Internal Consistency Tested
Cronbach's (Describe)

Crohnbach’s α =0.892.

B. Reliability intraobserver or test-retest Tested
Continuous scores: intraclass
correlation coefficient (ICC)
Dichotomus: Cohen kappa (Describe)

Patients were questioned 1-2 weeks after the baseline visit, whether they felt that their health status was stable, better or worse compared to the previous visit. Twenty-one PSS patients with stable health status were subsequently asked to complete the PSS-Qol a second time. Results of both PSS-QoL assessments were then compared.  Reliability of the PSS-QoL in these patients was high yielding an ICC of 0.958 (95% CI 0.926 to 0.981).

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 Tested
Expert opinion (relevance and
comprehensiveness) (Describe)

Face validity was tested by semi-structured interviews with patients and physicians and feasibility was determined by the percentage of missing data for each of the questions.

B. Construct Validity:
Structural validity
Not Tested
Hypotheses-testing Tested
Cross-cultural validity Tested
Brief Description
C. Criterion validity Not Tested
Comparison with a 'gold standard' Continuous scores:
correlations, ROC curves Dichotomus:
Sensitivity & Specificity (Describe)