Objective: In this study, we evaluated distinctive types of physical predisposition in patients with common side effects.
Method: We selected 500 and 1,200 individuals with and without a previous diagnosis of side effects, respectively, through web-based research.  Then, we conducted a decision tree analysis for investigating the status of 100 types of physical predisposition in these individuals.
Results and Conclusion: The individuals who had suffered from hepatic disorder and answered “relevant” for “predisposition to swelling” (likelihood ratio of a positive result [LR+] 2.17; p=0.004) and “very relevant” for “predisposition to skin dryness” (LR+ 3.52; p<0.001) enhanced the probability of extracting individuals who developed side effects.  The individuals who had suffered from skin disorder and answered “relevant” for “predisposition to eczema and inflammation” and “not relevant” for “predisposition to higher temperature” had an LR+ of 2.22 (p<0.001).  The individuals with “predisposition to worsening of physical condition on a rainy or high-humidity day” are more likely to develop side effects with the use of antibiotics and NSAIDs, compared to those without this predisposition (antibiotics: LR+ 2.33; NSAIDs: LR+ 2.51).  The results of this study indicate that we can identify patients with a high risk of side effects through an interview on predisposition.