VALIDATION DATA

MEASUREMENT PROPERTIES
Limitations
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 SvdH method for PsA has shown good intrarater reliability (ICC >0.97) in several studies of biologic agents.

C. Reliability interobserver or Measurement error Tested
Standard error of measurement (SEM),
smallest detectable change (SDC) or
Limits of agreement (LoA) (Describe)

Baseline interrater reliability was high at 0.95 (95% confidence interval: 0.83-0.99). Interrrater reliability at follow-up ranged was 0.92 for erosions and 0.96 for joint space narrowing.

2. VALIDITY
A. Content validity: face validity Not Tested
Expert opinion (relevance and
comprehensiveness) (Describe)

Not applicable.

B. Construct Validity:
Structural validity
Not Tested
Hypotheses-testing Not 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)