VALIDATION DATA

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

IRT: Person separation index >0.9

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

In order to investigate the test–retest reliability of the instrument, the questionnaire was administered twice to the sample, both times by post and separated by a period of two weeks. This revealed an ICC of 0.870 (p < 0.000). This set of reliability tests demonstrate good test–retest reliability and repeatability of the instrument

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)

Early research found the ENAT to be acceptable to patients

B. Construct Validity:
Structural validity
Tested
Hypotheses-testing Not Tested
Cross-cultural validity Tested
Brief Description

Confirmatory FA, structure detection & Rasch analysis  has been done; . In RA and SSc, the 7 domains of the ENAT were found to fit the Rasch model, X 2(df) = 16.953(14), p = 0.259 and 8.132(14), p = 0.882 for RA and SSc, respectively. OA group was a misfit.

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