Logistic regression model estimates of risk factors for chewing khat among high school students in eastern Ethiopia (n = 1,721)§.

§No multicollinearity was detected in the model, the mean variance inflation factor (VIF) was 2.05 and no variable had a VIF of more than 10. On case-wise diagnostics there were no residuals with values more than 3 standard deviations, indicating that there are no outlier cases.