Table 5.

Summary of measurement property validations.

Instrument	Structural validity	Internal consistency	Test-retest reliability	Criterion validity
	Result [Quality of measurement property]*	Result [Quality of measurement property]#	Result [Quality of measurement property]@	Result [Quality of measurement property]+
Traditional Chinese Medicine Functional Gastrointestinal Disorders Scale31	•Total CFI and RMSEA: 0.87; 0.064 • CFI and RMSEA of each identified factor (TCM pattern): ○ Stomach dampness-heat (pattern of FD) – 0.52; 0.15 ○ Liver qi depression (pattern of IBS) – 0.72; not reported ○ Liver qi invading the spleen (pattern of IBS) – 0.69; 0.17 ○ Spleen-stomach weakness (pattern of IBS) – 0.56; 0.16 ○ Cold-heat complex (pattern of IBS) – 0.81; 0.20 •[Insufficient]	Not validated	Not validated	Not validated
Traditional Chinese Medicine Syndrome Differentiation Instrument for Functional Gastrointestinal Disorders32	•Total CFI and RMSEA: 0.83; 0.052 •[Sufficient]	Not validated	Not validated	Not validated
Traditional Chinese Medicine Syndrome Differentiation Instrument for Functional Gastrointestinal Disorders (Amended)35	•KMO: 0.777 •Bartlett's sphericity test: p<0.001 • EFA: ○ 8 factors with eigenvalue >1, contributed to 59.4% of total variance ○ Factors were not related to TCM patterns •[Insufficient]	Not validated	Not validated	Not validated
Traditional Chinese Medicine Functional Dyspepsia Scale33	Not validated	Not validated	• Cohen's kappa of each identified factor (TCM pattern): ○ Spleen-stomach qi deficiency – 0.65 ○ Liver qi depression– 0.82 ○ Heat – 0.74 ○ Stagnation of phlegm-dampness – 0.76 ○ Qi stagnation – 0.68 •[Insufficient]	•Gold standard: Diagnosis made by Chinese medicine experts • Sensitivity and specificity of each factor (TCM pattern): ○ Spleen-stomach qi deficiency – 0.73; 0.95 ○ Liver qi depression – 0.88; 0.94 ○ Heat – 0.90; 0.90 ○ Stagnation of phlegm-dampness – 0.90; 0.89 ○ Qi stagnation – 0.76; 0.93 •[Indeterminate]
Stomach Qi Deficiency Pattern Assessment Scale34	Not validated	•Cronbach's alpha: 0.87 •[Indeterminate]	Not validated	•Gold standard: Diagnosis made by Korean medical doctors •Sensitivity: 93.33% •Specificity: 86.67% •AUC: 0.916 •[Sufficient]

CFI: Comparative fit index; TCM: Traditional Chinese Medicine; FD: Functional dyspepsia; IBS: Irritable bowel syndrome; RMSEA: Root mean square error of approximation; KMO: Kaiser-Meyer-Olkin Test; EFA: Exploratory factor analysis; AUC: Area under the Receiver Operator Curve

^⁎Sufficient: CFI >0.95 OR RMSEA <0.06; indeterminate: not all information for “sufficient” reported; insufficient: criteria for “sufficient” not met

^#Sufficient: Sufficient structural validity AND Cronbach's alpha(s) ≥0.70 for each unidimensional scale or subscale; indeterminate: criteria for “sufficient structural validity” not met; insufficient: sufficient structural validity AND Cronbach's alpha(s) <0.70 for each unidimensional scale or subscale

^@Sufficient: Cohen's kappa ≥0.70; indeterminate: Cohen's kappa not reported; insufficient: Cohen's kappa <0.70

⁺Sufficient: Correlation with gold standard ≥0.70 OR AUC ≥0.70; indeterminate: not all information for “sufficient” reported; insufficient: correlation with gold standard <0.70 OR AUC <0.70