Preprints with The Lancet is part of SSRN´s First Look, a place where journals identify content of interest prior to publication. Authors have opted in at submission to The Lancet family of journals to post their preprints on Preprints with The Lancet. The usual SSRN checks and a Lancet-specific check for appropriateness and transparency have been applied. Preprints available here are not Lancet publications or necessarily under review with a Lancet journal. These preprints are early stage research papers that have not been peer-reviewed. The findings should not be used for clinical or public health decision making and should not be presented to a lay audience without highlighting that they are preliminary and have not been peer-reviewed. For more information on this collaboration, see the comments published in The Lancet about the trial [https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)31125-5/fulltext] period, and our decision to make this a permanent [https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31950-4/fulltext] offering, or visit The Lancet´s FAQ [https://www.thelancet.com/preprints] page, and for any feedback please contact [email protected].