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Langford O, Aronson JK, van Valkenhoef G, Stevens RJ.Langford O, et al. Among authors: aronson jk.Stat Methods Med Res. 2018 Feb;27(2):564-578. doi: 10.1177/0962280216637093. Epub 2016 Mar 17.Stat Methods Med Res. 2018.PMID: 26994216