Skip to Content
Interactive Textbook on Clinical Symptom Research Logo


Home button

Trial Design: Pain Sections
Author Bio
Introduction
Placebo Effects
Currently selected section: Single Dose Trials
Repeated Dose Trials
Explanatory Versus Pragmatic
Dose-Response
Parallel Group Versus Crossover
Conclusion
 
Chapter 1: Clinical Trials of Pain Treatment: Single Dose Trials: Question 3.3
         

What can you conclude from these data?

You answered:

Selection ADrug X is not an effective analgesic in this condition.

Treatments were placebo and Drug X.  The figure shows that both of these treatments gave a modest amount of pain relief, less than one standard error different from each other.

INCORRECT

A finding of "no significant differences" is equivocal in a symptom study. The absence of a difference may reflect that the drug is truly ineffective or alternatively, that the study lacked sensitivity to demonstrate an effect.

Even if Drug X is truly analgesic, the assay may have been insensitive because patients had pain too severe to respond to the analgesic, the pain questionnaires were confusing, or the procedures of the nurse-observer inconstant. A final possibility is that the finding of no difference may have been a false negative due to random variation.

 

 Back to Question