VALIDATION DATA

MEASUREMENT PROPERTIES
Limitations English only
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 GISSK-Q had moderate test–retest reliability (weighted kappa 0.54, ICC = 0.60). The test–retest reliability of the GISSK-VAS was somewhat better (ICC = 0.67).

The quality of parent proxy-report of the GISSK-Q and GISSK-VAS was fair to good (ICCGISSK-Q= 0.47; ICCGISSK-VAS = 0.66).

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

GI symptom severity (GISSK-VAS) was highly correlated with the GISSK-Q scores (rSpearman= 0.75; P<0.0001). Based on univariate analysis, upper abdominal pain appeared to be particularly important for patients’ perceived GI symptom severity. This was also true for dyspepsia, anorexia, and vomiting, but these symptoms occurred less frequently in the studied patients.

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