The typical clinical trial compares two groups of patients. One group are given a placebo or conventional treatment, while the other group of patients are given the treatment that is being tested. The investigators running the clinical trial will wish to stop the trial early for ethical reasons if the treatment group clearly shows evidence of benefit. In other words, "when early results proved so promising it was no longer fair to keep patients on the older drugs for comparison, without giving them the opportunity to change."[2]
The Haybittle–Peto boundary is one such stopping rule, and it states that if an interim analysis shows a probability of equal to, or less than 0.001 that a difference as extreme or more between the treatments is found, given that the null hypothesis is true, then the trial should be stopped early. The final analysis is still evaluated at the normal level of significance (usually 0.05).[3][4] The main advantage of the Haybittle–Peto boundary is that the same threshold is used at every interim analysis, unlike the O'Brien–Fleming boundary, which changes at every analysis. Also, using the Haybittle–Peto boundary means that the final analysis is performed using a 0.05 level of significance as normal, which makes it easier for investigators and readers to understand. The main argument against the Haybittle–Peto boundary is that some investigators believe that the Haybittle–Peto boundary is too conservative and makes it too difficult to stop a trial.[5]
List of p-values used at each interim analysis, assuming the overall p-value for the trial is 0.05
^Pocock SJ (2005). "When (not) to stop a clinical trial for benefit". JAMA. 294 (17): 2228–30. CiteSeerX10.1.1.498.722. doi:10.1001/jama.294.17.2228. PMID 16264167.
^Hall C (5 September 2005). "Heart attacks may be cut by half". Daily Telegraph. p. 1.
^Haybittle, JL (1971). "Repeated assessments of results in clinical trials of cancer treatment". Br. J. Radiol. 44 (526): 793–797. doi:10.1259/0007-1285-44-526-793. PMID 4940475.
^Peto, R; Pike, MC; Armitage, P; et al. (1976). "Design and analysis of randomized clinical trials requiring prolonged observation of each patient. I. Introduction and design". Br. J. Cancer. 34 (6): 585–612. doi:10.1038/bjc.1976.220. PMC2025229. PMID 795448.
^Schulz KF, Grimes DA (2005). "Multiplicity in randomised trials, II: subgroup and interim analyses". Lancet. 365 (9471): 1657–1661. doi:10.1016/S0140-6736(05)66516-6. PMID 15885299.
December 30, 2022
haybittle, peto, boundary, rule, deciding, when, stop, clinical, trial, prematurely, named, john, haybittle, richard, peto, typical, clinical, trial, compares, groups, patients, group, given, placebo, conventional, treatment, while, other, group, patients, giv. The Haybittle Peto boundary is a rule for deciding when to stop a clinical trial prematurely 1 It is named for John Haybittle and Richard Peto The typical clinical trial compares two groups of patients One group are given a placebo or conventional treatment while the other group of patients are given the treatment that is being tested The investigators running the clinical trial will wish to stop the trial early for ethical reasons if the treatment group clearly shows evidence of benefit In other words when early results proved so promising it was no longer fair to keep patients on the older drugs for comparison without giving them the opportunity to change 2 The Haybittle Peto boundary is one such stopping rule and it states that if an interim analysis shows a probability of equal to or less than 0 001 that a difference as extreme or more between the treatments is found given that the null hypothesis is true then the trial should be stopped early The final analysis is still evaluated at the normal level of significance usually 0 05 3 4 The main advantage of the Haybittle Peto boundary is that the same threshold is used at every interim analysis unlike the O Brien Fleming boundary which changes at every analysis Also using the Haybittle Peto boundary means that the final analysis is performed using a 0 05 level of significance as normal which makes it easier for investigators and readers to understand The main argument against the Haybittle Peto boundary is that some investigators believe that the Haybittle Peto boundary is too conservative and makes it too difficult to stop a trial 5 List of p values used at each interim analysis assuming the overall p value for the trial is 0 05 Number ofplanned analyses Interim analysis p value threshold2 1 0 0012 final 0 053 1 0 0012 0 0013 final 0 054 1 0 0012 0 0013 0 0014 final 0 055 1 0 0012 0 0013 0 0014 0 0015 final 0 05Synonyms EditPeto boundary Peto method Peto criteriaSee also EditO Brien Fleming boundary Pocock boundaryReferences Edit Pocock SJ 2005 When not to stop a clinical trial for benefit JAMA 294 17 2228 30 CiteSeerX 10 1 1 498 722 doi 10 1001 jama 294 17 2228 PMID 16264167 Hall C 5 September 2005 Heart attacks may be cut by half Daily Telegraph p 1 Haybittle JL 1971 Repeated assessments of results in clinical trials of cancer treatment Br J Radiol 44 526 793 797 doi 10 1259 0007 1285 44 526 793 PMID 4940475 Peto R Pike MC Armitage P et al 1976 Design and analysis of randomized clinical trials requiring prolonged observation of each patient I Introduction and design Br J Cancer 34 6 585 612 doi 10 1038 bjc 1976 220 PMC 2025229 PMID 795448 Schulz KF Grimes DA 2005 Multiplicity in randomised trials II subgroup and interim analyses Lancet 365 9471 1657 1661 doi 10 1016 S0140 6736 05 66516 6 PMID 15885299 Retrieved from https en wikipedia org w index php title Haybittle Peto boundary amp oldid 1017187944, wikipedia, wiki, book, books, library,
