Glossary entry (derived from question below)
English term or phrase:
PBO-subtracted
English answer:
after subtracting the results (or mean) for the placebo group from the total results (or mean)
Added to glossary by
Charles Davis
Feb 3, 2015 09:59
9 yrs ago
9 viewers *
English term
PBO-subtracted
English
Science
Mathematics & Statistics
clinical trial
The effect size was calculated using a PBO-subtracted difference of xxx and a common standard deviation of yyy.
[what is subtracted from what?]
[what is subtracted from what?]
Change log
Apr 19, 2015 17:08: Charles Davis Created KOG entry
Responses
31 mins
Selected
after subtracting the results for the placebo group from the total results
PBO stands for placebo:
"Treatment with ODN 50 mg once weekly for 2 years resulted in placebo (PBO)-subtracted mean increases..."
http://press.endocrine.org/doi/abs/10.1210/endo-meetings.201...
"Placebo-subtracted response Research The response in a treatment group minus the response in a control/placebo group."
http://medical-dictionary.thefreedictionary.com/therapeutic ...
So "PBO-subtracted difference" means the difference after excluding the placebo: the results corresponding to the group in the trial that received a placebo are subtracted, leaving just the results for the group that received the actual treatment.
"Treatment with ODN 50 mg once weekly for 2 years resulted in placebo (PBO)-subtracted mean increases..."
http://press.endocrine.org/doi/abs/10.1210/endo-meetings.201...
"Placebo-subtracted response Research The response in a treatment group minus the response in a control/placebo group."
http://medical-dictionary.thefreedictionary.com/therapeutic ...
So "PBO-subtracted difference" means the difference after excluding the placebo: the results corresponding to the group in the trial that received a placebo are subtracted, leaving just the results for the group that received the actual treatment.
Peer comment(s):
| neutral |
DLyons
: Maybe.
75 days
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Aha! I'd completely forgotten this question. You may well have been right about this, but it's all water under the bridge now. Anyway, I've added "mean" to the glossary entry.
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4 KudoZ points awarded for this answer.
Comment: "Thank you!"
+1
7 hrs
Treatment effect less PBO effect
Without seeing the data I can't be sure, but what I think is happening is that there's a pre-trial baseline followed by a trial with Lacosamide and a placebo, both of which show a difference from the baseline. So the trial is displaying a placebo effect and, to be conservative, this is subtracted from the observed LCM treatment effect.
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Note added at 7 hrs (2015-02-03 17:25:32 GMT)
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So it's a difference of two means, LCM mean (over people who had this treatment) - PBO mean (over people who received placebo).
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Note added at 7 hrs (2015-02-03 17:25:32 GMT)
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So it's a difference of two means, LCM mean (over people who had this treatment) - PBO mean (over people who received placebo).
Discussion
A possibility is that the difference due to the treatment is being compared to an observed placebo difference (placebo/halo effect).