Conditional logistic regression will be used to estimate the odds ratios and corresponding 95% confidence intervals (CIs) of the association between domperidone use and the risk of VT/SCD. In secondary analyses, VT/SCD will be analyzed according to duration of domperidone use (<=30 days, >30 days), and to the daily dose of domperidone (<=30 mg per day, >30 mg per day). In addition, several sensitivity analyses will be conducted, all defined a priori, to assess the robustness of the results. Finally, all site-specific estimates will be meta-analyzed using fixed and random effects models. The amount of between-site heterogeneity will be estimated using the I square statistic.