Analysis Of Functional Gastrointestinal Disorders Scale Of Traditional Chinese Medicine Based On Syndrome Differentiation Using Structural Equation Model And Item Response Theory Methods

ObjectiveThis study was designed to develop FGID-scale based on syndrome differentiation by using structural equation model (SEM) and item response theory (IRT) methods.MethodsData were collected by the primary scale functional gastrointestinal disorders scale (FGID-scale), which were from 301 FGID patients and 61 healthy people.The hypothetical model was constructed based on presented papers, clinical experience, diagnostic and treatment guide, basic theory of traditional Chinese medicine, clinical diagnosis of Chinese medicine, and so on. The model includes nine syndrome(qi deficiency, liver depression, qi stagnation, qi upward flow, cold syndrome, dampness syndrome, heat syndrome, yin deficiency, yang deficiengcy) and five paths (Stagnation of Qi due to depression of the liver, spleen deficiency with dampness retention, retention of dampness due to stagnation of QI, yin deficiency generating interior heat, yang deficiency leading to cold).SEM and IRT were used to shorten FGID-scale. Two criteria were used to filter items for shortening scales. One is factor loadings value, the other is item discrimination parameter value. If both values are low, the item information function curve is low and flat, the item can be deleted refer to basic theory of traditional Chinese medicine. SEM is used to analyze the shortened FGID-scale model, the relationship between symptoms and syndromes, and the relationship between syndromes and syndromes. IRT was used to analyze the syndromes, to predict the abilities(include patients and healthy people), the mean of the abilities and standard error of estimation. Analysis of abilities with t-test is used to evaluate the discriminant validity.Result15 items were delected in the end, including wiry pulse, dense tongue coating, slippery tongue coating, slippery pulse, spontaneous sweating, like push, like to be press, teeth-marked tongue, bulgy, thin coating, white coating, veinlet, pink tongue, infrequent pulse, dry and sloppy stool from time to time, dislike of press. The shortened FGID-scale model had a good fit(x2/DF=1.82, GFI=0.88, RMSEA=0.052). The test information function does not change much. The shortend model is simpler than the first one.According to the item's factor loadings and the item discrimination parameter, the syndromes's primary symptom and secondary symptom can be distinguished. For liver depression, primary symptom indicates that the worse the mood, the more serious the illness becomes, while the secondary symptom is the pain of hypochondrium. For dampness syndrom, primary symptom is heaviness sensation of the head and body, while the secondary symptom is thick coating and diarrhea. For qi deficiency, primary symptom includes lassitude, distinclination to talk, tasteless and insipid. Inadvertent dining results in worse illness, dull pain. Its secondary symptom includes anorexia, fatigue, easy to feel full, spit. Stool is dry and then sloppy, and chance to be loose. For qi stagnation, primary symptom marked includes abdominal heaviness, fullness, and stool tenesmus, while the secondary symptom includes difficult elimination, bursting, pain-leading diarrhea and chest distress.The more manifested the livers depressed is, the more stagnate the qi is. The more deficient the qi is, the more stagnate it is. The more manifested the dampness syndrome is, the more deficient the qi is. Deficient of qi results in manifestated dampness syndrome, and then influences the activities of qi, and qi stagnates. However, dampness syndrome cannot cause qi deficient.Analyzed the mean of patients and healthy people's syndrome ability with t-test (P<0.05), the mean is statistically significant difference. It indicate the model have the ability to discriminate the patients and healthy people. The discriminant validity is good.ConclusionThe Traditional Chinese Medicine based on syndrome differentiation model has a good fit, conform the basic theory of traditional Chinese medicine the syndrome ability can discriminate the patients and healthy people. Traditional Chinese Medicine based on syndrome differentiation is a valid disease-specific instrument used for measuring the Traditional Chinese medicine curative effect.