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The randomized placebo-phase design: Evaluation, interim monitoring and analysis

Shook, Stephanie Lauren (2010) The randomized placebo-phase design: Evaluation, interim monitoring and analysis. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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The randomized placebo-phase design, also known as the randomized delayed-start design, has been proposed as an approach to circumvent the reluctance of patients and physicians to participate in trials with a placebo control. Although there is some practical appeal to the design and it has been used in an increasing number of active and ongoing trials, there are often overlooked issues relative to statistical power, estimating sample size and determining plans for interim analysis that may limit its usefulness. We developed a general model for describing the pattern of treatment response and based on the specified parameters of this model, derive and compare different strategies for interim monitoring. In addition to statistical power considerations, we also provide results from extensive simulations investigating the robustness of the proposed procedures since the efficiency of the randomized placebo-phase design is highly dependent on the assumptions made about the form of the alternative hypotheses. Public Health Relevance: The randomized clinical trial is the gold standard for evaluating new medical treatments/public health interventions. Indiscriminate use of the RPPD may result in failure to identify important new treatment/interventions because of low statistical power.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Shook, Stephanie
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairRockette, Howardherbst@pitt.eduHERBST
Committee MemberWahed, Abduswahed@pitt.eduWAHED
Committee MemberJeong, Jongjeong@nsabp.pitt.eduJJEONG
Committee MemberBelle, Stephenbelle@edc.pitt.eduSBELLE
Date: 29 September 2010
Date Type: Completion
Defense Date: 29 July 2010
Approval Date: 29 September 2010
Submission Date: 22 July 2010
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Institution: University of Pittsburgh
Schools and Programs: School of Public Health > Biostatistics
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: Clinical trials; Delayed treatment; Interim monitoring; Randomized placebo-phase design; Statistical power
Other ID:, etd-07222010-162315
Date Deposited: 10 Nov 2011 19:53
Last Modified: 15 Nov 2016 13:46


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