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Trial Design: Pain Sections
Author Bio
Introduction
Placebo Effects
Single Dose Trials
Currently selected section: Repeated Dose Trials
Explanatory Versus Pragmatic
Dose-Response
Parallel Group Versus Crossover
Conclusion
 
Chapter 1: Clinical Trials of Pain Treatment: Repeated Dose Trials: Problem 4.1: Question 4.1.2
 
 

Does this result demonstrate morphine intake provides adequate “assay sensitivity”?

You answered:

No.
This result demonstrates that measurement of morphine intake but not pain provided adequate "assay sensitivity" for the evaluation of Drug K as an analgesic.


CORRECT


Demonstration of a significant difference in an outcome suggests that one has carried out a clinical assay sensitive enough to measure an effect on that outcome, but as discussed in the previous question, it is not clear that the reduction in PCA morphine administration is due to pain relief or to something else. The failure to show a difference in pain scores may not be an assay sensitivity problem, but may reflect that Drug K is just not an effective analgesic in postoperative pain. Alternatively, there may have been a deficiency in the study methods or execution that would have obscured a true analgesic effect. Many analgesic experts agree that allowing patients to self-administer opioids during the study, while sometimes ethically necessary, reduces assay sensitivity. Devising outcome measures that combine pain report and requirements for rescue medication may restore part of this sensitivity, but requires the assumption that analgesic self-administration is an accurate reflection of pain.

 

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