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A general parametric approach to the meta-analysis of randomized clinical trials.
Whitehead A, Whitehead J. Whitehead A, et al. Among authors: whitehead j. Stat Med. 1991 Nov;10(11):1665-77. doi: 10.1002/sim.4780101105. Stat Med. 1991. PMID: 1792461
Meta-analysis provides a systematic and quantitative approach to the summary of results from randomized studies. Whilst many authors have published actual meta-analyses concerning specific therapeutic questions, less has been published about comprehensive methodology. This …
Meta-analysis provides a systematic and quantitative approach to the summary of results from randomized studies. Whilst many authors …
Sample size requirements to estimate key design parameters from external pilot randomised controlled trials: a simulation study.
Teare MD, Dimairo M, Shephard N, Hayman A, Whitehead A, Walters SJ. Teare MD, et al. Among authors: whitehead a. Trials. 2014 Jul 3;15:264. doi: 10.1186/1745-6215-15-264. Trials. 2014. PMID: 24993581 Free PMC article.
We also illustrate the consequences of using a confidence interval argument to inflate estimates so the required power is achieved with a pre-specified level of confidence. ...If the event rate in an intervention group needs to be estimated by the pilot then a
We also illustrate the consequences of using a confidence interval argument to inflate estimates so the required power is achieved wi …
An audit of sample sizes for pilot and feasibility trials being undertaken in the United Kingdom registered in the United Kingdom Clinical Research Network database.
Billingham SA, Whitehead AL, Julious SA. Billingham SA, et al. Among authors: whitehead al. BMC Med Res Methodol. 2013 Aug 20;13:104. doi: 10.1186/1471-2288-13-104. BMC Med Res Methodol. 2013. PMID: 23961782 Free PMC article.
BACKGROUND: There is little published guidance as to the sample size required for a pilot or feasibility trial despite the fact that a sample size justification is a key element in the design of a trial. ...CONCLUSION: All studies should have a
BACKGROUND: There is little published guidance as to the sample size required for a pilot or feasibility trial despite the fact that …
Stopping rules for phase II studies.
Stallard N, Whitehead J, Todd S, Whitehead A. Stallard N, et al. Among authors: whitehead j, whitehead a. Br J Clin Pharmacol. 2001 Jun;51(6):523-9. doi: 10.1046/j.0306-5251.2001.01381.x. Br J Clin Pharmacol. 2001. PMID: 11422011 Free PMC article. Review.
Phase II trials are generally small-scale studies, and may include one or more experimental treatments with or without a control. A common feature is that the results primarily determine the course of further clinical evaluation of a treatment rather than pro …
Phase II trials are generally small-scale studies, and may include one or more experimental treatments with or without a control. …
Mid-trial design reviews for sequential clinical trials.
Whitehead J, Whitehead A, Todd S, Bolland K, Sooriyarachchi MR. Whitehead J, et al. Among authors: whitehead a. Stat Med. 2001 Jan 30;20(2):165-76. doi: 10.1002/1097-0258(20010130)20:2<165::aid-sim649>3.0.co;2-a. Stat Med. 2001. PMID: 11169595
When sequential clinical trials are conducted by plotting a statistic measuring treatment difference against another measuring information, power is guaranteed regardless of nuisance parameters. ...In the special cases of trials with a relatively short recruitment p …
When sequential clinical trials are conducted by plotting a statistic measuring treatment difference against another measuring inform …
Interim analyses and sequential designs in phase III studies.
Todd S, Whitehead A, Stallard N, Whitehead J. Todd S, et al. Among authors: whitehead a, whitehead j. Br J Clin Pharmacol. 2001 May;51(5):394-9. doi: 10.1046/j.1365-2125.2001.01382.x. Br J Clin Pharmacol. 2001. PMID: 11421995 Free PMC article.
Recruitment of patients to a clinical trial usually occurs over a period of time, resulting in the steady accumulation of data throughout the trial's duration. ...For ethical and economic reasons, the technique of sequential testing has been developed to enable the …
Recruitment of patients to a clinical trial usually occurs over a period of time, resulting in the steady accumulation of data …
Statistical evaluation of the revised fixed-dose procedure.
Stalla N, Whitehead A, Ridgway P. Stalla N, et al. Among authors: whitehead a. Hum Exp Toxicol. 2002 Apr;21(4):183-96. doi: 10.1191/0960327102ht239oa. Hum Exp Toxicol. 2002. PMID: 12099620
The likelihood of achieving the same classification is greatest for substances with a steep dose-response curve and median toxic dose (TD50) close to the LD50. The revised FDP usually requires five or six animals with two or fewer dying as a result of treatment in m …
The likelihood of achieving the same classification is greatest for substances with a steep dose-response curve and median toxic dose …
Meta-analysis of ordinal outcomes using individual patient data.
Whitehead A, Omar RZ, Higgins JP, Savaluny E, Turner RM, Thompson SG. Whitehead A, et al. Stat Med. 2001 Aug 15;20(15):2243-60. doi: 10.1002/sim.919. Stat Med. 2001. PMID: 11468762
A general framework is proposed for fixed and random effect models. Tests of the validity of the various assumptions made in the meta-analysis models, such as a global test of the assumption of proportional odds between treatments, are presented. ...The methods are
A general framework is proposed for fixed and random effect models. Tests of the validity of the various assumptions made in the meta
A prospectively planned cumulative meta-analysis applied to a series of concurrent clinical trials.
Whitehead A. Whitehead A. Stat Med. 1997 Dec 30;16(24):2901-13. doi: 10.1002/(sici)1097-0258(19971230)16:24<2901::aid-sim700>3.0.co;2-5. Stat Med. 1997. PMID: 9483722
Consider the situation where a series of studies is to be conducted, following broadly similar protocols comparing a new treatment with a control treatment. ...A simulated example illustrates a number of practical issues....
Consider the situation where a series of studies is to be conducted, following broadly similar protocols comparing a new treat …
Borrowing strength from external trials in a meta-analysis.
Higgins JP, Whitehead A. Higgins JP, et al. Among authors: whitehead a. Stat Med. 1996 Dec 30;15(24):2733-49. doi: 10.1002/(SICI)1097-0258(19961230)15:24<2733::AID-SIM562>3.0.CO;2-0. Stat Med. 1996. PMID: 8981683
There exists a variety of situations in which a random effects meta-analysis might be undertaken using a small number of clinical trials. ...Two approaches to estimating relative efficacy are considered, namely a general parametric approach and a
There exists a variety of situations in which a random effects meta-analysis might be undertaken using a small number o …
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