VALIDATION DATA

MEASUREMENT PROPERTIES
Limitations <5 European languages (English)
Observations
1. RELIABILITY
A. Internal Consistency Not Tested
Cronbach's (Describe)

Cronbach's α = 0.63

B. Reliability intraobserver or test-retest Not Tested
Continuous scores: intraclass
correlation coefficient (ICC)
Dichotomus: Cohen kappa (Describe)
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)

The HUPI was developed by analyzing the balance between simplicity, reliability, accuracy, and sensitivity. In the resulting versions, the variables were weighted according to their quartile distribution in the study population. The best index, the HUPI10, used a common score for SJC and GDA‐P and a sex‐adjusted score for TJC and ESR. The HUPI has therefore face validity.

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

The AUC for the HUPI was very high (0.956), slightly larger than that of the DAS28‐ESR (0.930; P = 0.001) or the DAS28‐CRP (0.945; P = 0.077), and similar to that of the SDAI (0.957; P = 0.971) and the CDAI (0.964; P = 0.343).