Everyone who has made substantial intellectual contributions to the study on which the article is based (for example, to the research question, design, analysis, interpretation, and written description) should be an author. Only an individual who has made substantial intellectual contributions should be an author. Performing technical services, translating text, identifying patients for study, supplying materials, and providing funding or administrative oversight over facilities where the work was done are not, in themselves, sufficient for authorship, although these contributions may be acknowledged in the manuscript. One author (a “guarantor”) should take responsibility for the integrity of the work as a whole. Often this is the corresponding author, the one who sends in the manuscript and receives reviews, but other authors can have this role.