This article introduces the Stata menu-driven program steppedwedge, which calculates detectable differences and power for stepped-wedge randomized trials. The command permits continuous, binary, and rate outcomes (with normal approximations) for comparisons using two-sided tests. The command...

Using individual patient data from five independent surveys, we evaluate regional variations in survival in cerebral palsy. The influence of four important variables measuring disability, which are only partially observed for many cases, are analysed. Results are compared between a naive...

We introduce the Stata menu-driven command clustersampsi, which calculates sample sizes, detectable differences, and power for cluster randomized controlled trials. The command permits continuous, binary, and rate outcomes (with normal approximations) for comparisons of two-sided tests in two...

We describe a quantitative and comparative review of a selection of European birthweight standards for gestational age for singletons, to enable appropriate choices to be made for clinical and research use. Differences between median values at term across standards in 10 regions and...

Purpose: Observational studies may provide important information on the long-term effects of treatments for epilepsy, but systematic reviews of observational studies may be more prone to heterogeneity and biases. These issues were investigated in a systematic review of non-randomised add-on...

We describe a quantitative and comparative review of a selection of European birthweight standards for gestational age for singletons, to enable appropriate choices to be made for clinical and research use. Differences between median values at term across standards in 10 regions and...