RESUMO
Objective To observe the response of common indices for clinical effect evaluation on irritable bowel syndrome (IBS), thereby providing reference for IBS related clinical indices in clinical trials of Chinese medicine (CM). Methods A randomized, double-blinded, placebo control trial was set up. Totally 58 diarrhea-predominant IBS (IBS-D) patients were randomly assigned to the test group (28 cases) and the control group (30 cases). Patients in the test group took Chang'an Recipe I (CR I), while those in the control group took CR I placebo. The therapeutic course for all was 8 weeks. Defeca- tion related symptoms was taken as significance in clinics. Principal component analysis was performed in symptoms index. IBS symptom severity score (IBS-SSS) and IBS quality of life (IBS-QOL) were taken as dependent variables. Main component value and the integral of hospital anxiety and depression scale a (HADa) and hospital anxiety and depression scale d (HADd) were taken as independent variables. Their linear correlation was analyzed. Adequate relief (AR) value was taken as dependent variable, while symptoms index was taken as independent variable. Their Logistic regression correlation was analyzed. Main component value A and B of symptoms index were taken as measurement index. A group with effi- cacy was selected from the test group or the control group, and response analyzed in patients of this group. Results There was statistical difference in main component value of A and B in the test group after treatment (P <0.05). So data of the test group were taken as referential standard, the responsibili- ties of IBS-SSS, AR, IBS-QOL were observed. (1) The score of IBS-SSS had a linear regression with defecation related symptoms and anxiety scores, and its responsibility was higher with an effect size of 1.59. (2) Response to each AR was linearly related to defecation related symptoms.(3) The score of IBS-QOL was not obviously correlated with defecation related symptoms, but with moderate response to anxiety state (an effect size of 0. 61). Domains of dysphoria and worries about health could reflect clinical changes with the effect size of 0. 50 and 0. 70 respectively. Conclusions IBS-SSS had better clinical response, which was suitable for IBS clinical effect evaluation. Response to each AR was related with defe- cation related symptoms. But attention should be paid to its clinical meaning. IBS-QOL had a moderate effect size. It was suggested to be used in long-term clinical research.