Abstract: Objective To explore the influencing factors of suspected allergic reactions caused by Yinzhihuang granules in the real world. Methods This study collected information form 4 966 patients who had used Yinzhihuang granules in the hospital information systems of 21 tertiary hospitals across the country from March 2008 to March 2011. Prescription sequence analysis and nested case-control study were performed, prescription sequence analysis and nested case-control study were performed to select the allergic group and the control group (non-allergic patients) to find out about the potential relationship between the medication allergy to Yinzhihuang granules and forty-three influencing factors including the combination of diseases, combined medication, age, sex, length of hospital stay, course of treatment and dosage using the conditional Logistic regression analysis model. Results Single factor Logistic regression showed that three factors, including ascites, viral hepatitis B and the active stage of post-hepatitis cirrhosis, were statistically significant (P<0.05). After the univariate analysis results were incorporated into the multivariate Logistic regression model, no statistical significance was observed for the above three factors (P>0.05). Conclusion Based on the current sample size, no statistically significant factors related to allergic reactions caused by Yinzhihuang granules have been screened out. Real risk factors remain to be discovered and confirmed by pharmacological and clinical studies.

Key words: Yinzhihuang granules, suspected allergic reaction, real world, nested case-control study, Logistic regression