Browsing by Author "Chen, Henian"

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    How big is a big hazard ratio in clinical trials?
    (2023-09) Lu, Yuanyuan; Cen, Weiliang; Wang, Wei; Huang, Yangxin; Chen, Henian
    Background: Thehazardratio(HR)hasbeenwidelyusedasanindexofeffectsizeinclinicaltrialsfortime-to-eventdata.TheuseoftheCoxproportionalhazardsmodelsandotherhazardcenteredmodelsisubiquitousinclinicaltrialsfortime-to-eventdata.Therelativityofeffectsizes(small,medium,large)hasbeenwidelydiscussedandacceptedwhencomparingmagnitudeofassociationforcontinuousandcategoricaldata,butnotyetfortime-to-eventoutcomes.Methods: We review published hazard ratios, investigate the relationships among HR, relative risk (RR), odds ratio (OR), and Cohen’s d, and calculate the corresponding HRs for given event rate in control group (??0) by adding standard normal deviation with 0.2 (small), 0.5 (medium) and 0.8 (large) to the event rate in the case group (??1)based on equation ??1=1?(1???0)????.Results: OurresultsindicatethatHRsarefrom1.68to1.16whentheeventrateofcontrolgroupmovesfrom1%to90%,whichareequivalenttoCohen’sd=0.2(small).HRsarerangedbetween3.43and1.43whentheeventrateofcontrolgroupmovesfrom1%to90%,whichareequivalenttoCohen’sd=0.5(medium),HRsarevaluedbetween6.52and1.73whentheeventrateofcontrolgroupmovesfrom1%to90%,whichareequivalenttoCohen’sd=0.8(large).Conclusions: This study provides general guidelines in interpreting the magnitudes of HRs for time-to-event data in clinical trials