Clinical Trial Design
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ا ت ک ي د ز يم ا ا ه ي بClinical Trial Design Dr. Khalili 1 The common types Advantages and limitati Usual applications
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به نام ايزد يکتا. Clinical Trial Design. The common types Advantages and limitations Usual applications. Clinical Trial (on patients) vs. Field Trial (on healthy people) Community Trial (on communities). Before. After. Intervention. In phase II clinical trials OR - PowerPoint PPT Presentation
Transcript of Clinical Trial Design
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به نام ايزد يکتا
Clinical Trial Design
Dr. Khalili
The common types Advantages and limitations Usual applications
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Clinical Trial (on patients)vs.
Field Trial (on healthy people)
Community Trial (on communities)
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AfterBefore Intervention
In phase II clinical trials OR in serious diseases such as cancers
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Notice: the standard methods for sample size calculation and data analysis considering subject as analysis unit are not appropriate here.
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Be relax forfew minutes
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• Advantages:
Allows within-patients comparisons of treatments
Removes interpatient variabilityProvides the best unbiased estimates for
the differences between treatmentsDecreases number of patients needed
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• Limitations:• It is applicable where:
Objective measures for efficacy and safety are obtained Chronic and relatively stable disease Prophylactic drugs with relatively short half life Relatively short treatment periods Baseline and washout periods are feasible
• It increases the duration of the study• Its analysis is not straightforward:
The paired design The period and carry-over effects
• The effect of loss to follow-up
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• Sequence (Period) Effect: The order in which the therapies are given may
elicit psychological responses. Patients may react differently to the first
therapy given in a study as a result of the enthusiasm may diminish over
time.
• Carryover Effect: If a subject is changed from therapy A to therapy B and
observed under each therapy, the observations under therapy B will be
valid only if there is no residual carryover from therapy A. There must be
enough of a washout period to be sure none of therapy A or its effect
remains.
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To resolve the problom:
Two applications:1. Quantifying the interaction between the
two treatments2. Opportunistic situations
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A Full (a+1) * (b+1) Factorial Design for Combination Therapy of Two Components at a and b Dose Levels
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Designs with ethical considerations
• Adaptive Randomization
• Zelen design
• Variations of placebo-controlled trials:
• Add-on design
• Replacement design
• Randomized Withdrawal design
• Sequential analysis
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And more complex DESIGNS …
