<> <http://www.w3.org/2000/01/rdf-schema#comment> "The repository administrator has not yet configured an RDF license."^^<http://www.w3.org/2001/XMLSchema#string> . <> <http://xmlns.com/foaf/0.1/primaryTopic> <https://discovery.ucl.ac.uk/id/eprint/10046121> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ontology/bibo/AcademicArticle> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ontology/bibo/Article> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/dc/terms/title> "Power and sample-size analysis for the Royston–Parmar combined test in clinical trials with a time-to-event outcome"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/ontology/bibo/abstract> "Randomized controlled trials with a time-to-event outcome are usually designed and analyzed assuming proportional hazards (PH) of the treatment effect. The sample-size calculation is based on a log-rank test or the nearly identical Cox test, henceforth called the Cox/log-rank test. Nonproportional hazards (non-PH) has become more common in trials and is recognized as a potential threat to interpreting the trial treatment effect and the power of the log-rank test—hence to the success of the trial. To address the issue, in 2016, Royston and Parmar (BMC Medical Research Methodology 16: 16) proposed a \"combined test\" of the global null hypothesis of identical survival curves in each trial arm. The Cox/logrank test is combined with a new test derived from the maximal standardized difference in restricted mean survival time (RMST) between the trial arms. The test statistic is based on evaluations of the between-arm difference in RMST over several preselected time points. The combined test involves the minimum p-value across the Cox/log-rank and RMST-based tests, appropriately standardized to have the correct distribution under the global null hypothesis. In this article, I introduce a new command, power_ct, that uses simulation to implement power and sample-size calculations for the combined test. power_ct supports designs with PH or non-PH of the treatment effect. I provide examples in which the power of the combined test is compared with that of the Cox/log-rank test under PH and non-PH scenarios. I conclude by offering guidance for sample-size calculations in time-to-event trials to allow for possible non-PH."^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/dc/terms/date> "2018" . <https://discovery.ucl.ac.uk/id/document/643441> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ontology/bibo/Document> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/ontology/bibo/volume> "18" . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/ontology/bibo/issue> "1" . <https://discovery.ucl.ac.uk/id/org/ext-11db7c865d6bf7011adbe052363fe8ed> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Organization> . <https://discovery.ucl.ac.uk/id/org/ext-11db7c865d6bf7011adbe052363fe8ed> <http://xmlns.com/foaf/0.1/name> "StataCorp"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/dc/terms/publisher> <https://discovery.ucl.ac.uk/id/org/ext-11db7c865d6bf7011adbe052363fe8ed> . <https://discovery.ucl.ac.uk/id/publication/ext-1536867X> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ontology/bibo/Collection> . <https://discovery.ucl.ac.uk/id/publication/ext-1536867X> <http://xmlns.com/foaf/0.1/name> "Stata Journal"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/dc/terms/isPartOf> <https://discovery.ucl.ac.uk/id/publication/ext-1536867X> . <https://discovery.ucl.ac.uk/id/publication/ext-1536867X> <http://www.w3.org/2002/07/owl#sameAs> <urn:issn:1536867X> . <https://discovery.ucl.ac.uk/id/publication/ext-1536867X> <http://purl.org/ontology/bibo/issn> "1536867X" . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/ontology/bibo/status> <http://purl.org/ontology/bibo/status/published> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/dc/terms/creator> <https://discovery.ucl.ac.uk/id/person/ext-7a838e033e3026c3b6f8051fec726a6c> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/ontology/bibo/authorList> <https://discovery.ucl.ac.uk/id/eprint/10046121#authors> . <https://discovery.ucl.ac.uk/id/eprint/10046121#authors> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_1> <https://discovery.ucl.ac.uk/id/person/ext-7a838e033e3026c3b6f8051fec726a6c> . <https://discovery.ucl.ac.uk/id/person/ext-7a838e033e3026c3b6f8051fec726a6c> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person> . <https://discovery.ucl.ac.uk/id/person/ext-7a838e033e3026c3b6f8051fec726a6c> <http://xmlns.com/foaf/0.1/givenName> "P"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/person/ext-7a838e033e3026c3b6f8051fec726a6c> <http://xmlns.com/foaf/0.1/familyName> "Royston"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/person/ext-7a838e033e3026c3b6f8051fec726a6c> <http://xmlns.com/foaf/0.1/name> "P Royston"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://eprints.org/ontology/EPrint> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://eprints.org/ontology/ArticleEPrint> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/dc/terms/isPartOf> <https://discovery.ucl.ac.uk/id/repository> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://eprints.org/ontology/hasDocument> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643441> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://eprints.org/ontology/Document> . <https://discovery.ucl.ac.uk/id/document/643441> <http://www.w3.org/2000/01/rdf-schema#label> "Power and sample-size analysis for the Royston–Parmar combined test in clinical trials with a time-to-event outcome (Text)"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://purl.org/dc/elements/1.1/hasVersion> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://eprints.org/ontology/hasPublished> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643441> <http://eprints.org/ontology/hasFile> <https://discovery.ucl.ac.uk/id/eprint/10046121/1/Royston_sjart_st0510.pdf> . <https://discovery.ucl.ac.uk/id/document/643441> <http://purl.org/dc/terms/hasPart> <https://discovery.ucl.ac.uk/id/eprint/10046121/1/Royston_sjart_st0510.pdf> . <https://discovery.ucl.ac.uk/id/eprint/10046121/1/Royston_sjart_st0510.pdf> <http://www.w3.org/2000/01/rdf-schema#label> "Royston_sjart_st0510.pdf"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://eprints.org/ontology/hasDocument> <https://discovery.ucl.ac.uk/id/document/643442> . <https://discovery.ucl.ac.uk/id/document/643442> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://eprints.org/ontology/Document> . <https://discovery.ucl.ac.uk/id/document/643442> <http://www.w3.org/2000/01/rdf-schema#label> "Power and sample-size analysis for the Royston–Parmar combined test in clinical trials with a time-to-event outcome (Other)"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/document/643442> <http://eprints.org/relation/isVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643442> <http://eprints.org/relation/isVolatileVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643442> <http://eprints.org/relation/islightboxThumbnailVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://eprints.org/ontology/hasDocument> <https://discovery.ucl.ac.uk/id/document/643443> . <https://discovery.ucl.ac.uk/id/document/643443> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://eprints.org/ontology/Document> . <https://discovery.ucl.ac.uk/id/document/643443> <http://www.w3.org/2000/01/rdf-schema#label> "Power and sample-size analysis for the Royston–Parmar combined test in clinical trials with a time-to-event outcome (Other)"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/document/643443> <http://eprints.org/relation/isVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643443> <http://eprints.org/relation/isVolatileVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643443> <http://eprints.org/relation/ispreviewThumbnailVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://eprints.org/ontology/hasDocument> <https://discovery.ucl.ac.uk/id/document/643444> . <https://discovery.ucl.ac.uk/id/document/643444> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://eprints.org/ontology/Document> . <https://discovery.ucl.ac.uk/id/document/643444> <http://www.w3.org/2000/01/rdf-schema#label> "Power and sample-size analysis for the Royston–Parmar combined test in clinical trials with a time-to-event outcome (Other)"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/document/643444> <http://eprints.org/relation/isVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643444> <http://eprints.org/relation/isVolatileVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643444> <http://eprints.org/relation/ismediumThumbnailVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://eprints.org/ontology/hasDocument> <https://discovery.ucl.ac.uk/id/document/643445> . <https://discovery.ucl.ac.uk/id/document/643445> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://eprints.org/ontology/Document> . <https://discovery.ucl.ac.uk/id/document/643445> <http://www.w3.org/2000/01/rdf-schema#label> "Power and sample-size analysis for the Royston–Parmar combined test in clinical trials with a time-to-event outcome (Other)"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/document/643445> <http://eprints.org/relation/isVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643445> <http://eprints.org/relation/isVolatileVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643445> <http://eprints.org/relation/issmallThumbnailVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://eprints.org/ontology/hasDocument> <https://discovery.ucl.ac.uk/id/document/643446> . <https://discovery.ucl.ac.uk/id/document/643446> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://eprints.org/ontology/Document> . <https://discovery.ucl.ac.uk/id/document/643446> <http://www.w3.org/2000/01/rdf-schema#label> "Power and sample-size analysis for the Royston–Parmar combined test in clinical trials with a time-to-event outcome (Other)"^^<http://www.w3.org/2001/XMLSchema#string> . <https://discovery.ucl.ac.uk/id/document/643446> <http://eprints.org/relation/isVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643446> <http://eprints.org/relation/isVolatileVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/document/643446> <http://eprints.org/relation/isIndexCodesVersionOf> <https://discovery.ucl.ac.uk/id/document/643441> . <https://discovery.ucl.ac.uk/id/eprint/10046121> <http://www.w3.org/2000/01/rdf-schema#seeAlso> <https://discovery.ucl.ac.uk/id/eprint/10046121/> . 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