Association of Single-Blind Placebo Run-in Periods With the Placebo Response in Randomized Clinical Trials of Antidepressants

2021 ◽  
Author(s):  
Amelia J. Scott ◽  
Louise Sharpe ◽  
Veronica Quinn ◽  
Ben Colagiuri
Keyword(s):  
Clinical Trials ◽  
Randomized Clinical Trials ◽  
Placebo Response ◽  
Single Blind

Placebo and nocebo effects in randomized double-blind clinical trials for fatigue in advanced cancer patients

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 9640-9640
Author(s):  
M. de la Cruz ◽  
D. Hui ◽  
H. A. Parsons ◽  
P. Lynn ◽  
C. Parker ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Side Effects ◽  
Cancer Patients ◽  
Advanced Cancer ◽  
Randomized Clinical Trials ◽  
Placebo Response ◽  
Well Being ◽  
Advanced Cancer Patients ◽  
Edmonton Symptom Assessment Scale ◽  
Nocebo Effects

9640 Background: We have previously reported significant placebo response in randomized controlled treatment trials for cancer related fatigue (CRF). We conducted a retrospective study to determine the frequency and predictors of response to placebo and nocebo effect in patients with CRF. Methods: We reviewed patients that received placebo in two previous randomized clinical trials conducted by our group and determined the proportion of patients who demonstrated clinical response to fatigue using an increase (ΔFACIT-F score) > 7 from baseline to day 8, and those with nocebo response as those who reported side effects. Baseline patient characteristics and symptoms recorded from the Edmonton Symptom Assessment Scale (ESAS) were analyzed to determine their association with placebo and nocebo effects. Results: A total of 105 advanced cancer patients received placebo. 59 (56%) patients responded to placebo (median Δ FACIT-F score of 22). Worse baseline anxiety and well-being subscale score (univariate) and well-being (multivariate, MR) were significantly associated with placebo response. Common side effects reported were insomnia (79%), anorexia (53%), nausea (38%) and restlessness (34%). MR analysis showed that worse baseline (ESAS) sleep, appetite, nausea, and restless are associated with increased reporting of these side effects ( Table ). Conclusions: Nearly half of advanced cancer patients enrolled in the fatigue trials responded to placebo. Worse physical well-being score was associated with placebo response. Patients experiencing specific symptoms at baseline were more likely to report these as side effects of the medication. These findings should be considered in fatigue clinical trial design. [Table: see text] No significant financial relationships to disclose.

Placebo Response in Clinical Randomized Trials of Analgesics in Migraine

Cephalalgia ◽  
2003 ◽  
Vol 23 (7) ◽  
pp. 487-490 ◽  
Author(s):  
L Bendtsen ◽  
P Mattsson ◽  
J-A Zwart ◽  
RB Lipton
Keyword(s):  
Clinical Trials ◽  
Randomized Clinical Trials ◽  
Response Rate ◽  
International Headache Society ◽  
Placebo Response ◽  
Patient Characteristics ◽  
Placebo Treatment ◽  
Primary Efficacy ◽  
Efficacy Parameter ◽  
Efficacy Measure

The objective was to assess the placebo response in randomized clinical trials of analgesics in the treatment of migraine attacks. We included placebo-controlled studies that used the criteria of the International Headache Society for the diagnosis of migraine and headache response as the primary efficacy parameter. In the 11 studies that qualified for inclusion, headache response occurred after placebo treatment in 7-50% of the migraineurs with an average placebo response rate of 30% (95% confidence interval (CI) 23-36). Two hours after treatment with placebo an average of 9% (95% CI 7-12, range 7-17%) of the patients were found to be pain free. In conclusion, the average headache response rate to placebo was 30% in randomized clinical trials of analgesics in migraine with a tremendous variation among studies. Placebo response rates vary with the choice of primary efficacy measure as well as patient characteristics and study design.

scholarly journals Biphasic feature of placebo response in primary insomnia: pooled analysis of data from randomized controlled clinical trials of orexin receptor antagonists

SLEEP ◽  
2019 ◽  
Vol 43 (3) ◽  
Author(s):  
Dongmei He ◽  
Binghu Jiang ◽  
Zhiwei Guo ◽  
Qiwen Mu ◽  
Morgan A Mcclure
Keyword(s):  
Clinical Trials ◽  
Randomized Clinical Trials ◽  
Meta Analysis ◽  
Placebo Response ◽  
Pooled Analysis ◽  
Primary Insomnia ◽  
Subjective Measures ◽  
Receptor Antagonists ◽  
Double Blind

Abstract Objectives The placebo response to orexin receptor antagonists in primary insomnia is little-known. Our aim was, therefore, to conduct a systematic review of placebo-controlled randomized clinical trials to characterize placebo response. Methods We performed a comprehensive literature search for randomized, placebo-controlled, double-blind clinical trials evaluating the efficacy of orexin receptor antagonists addressing primary insomnia. To pool effect size estimates (Cohen’s d) of placebo and orexin receptor antagonists across trials for outcome measures, a meta-analysis was done according to the Cochrane guideline. Results The placebo response was significant and robust to improve the symptoms of insomnia in terms of objective and subjective measures, and the effects (0.70 ± 0.51) in subjective measures were smaller than that (1.10 ± 1.14) in objective measures (p = 0.027). The biphasic feature of placebo response showed an initial short-term increase of placebo effect and subsequent changeless long-term effect. Conclusion The biphasic feature of placebo response is clinically useful, and neuroimaging is essential to clarify the long-term mechanism in the future.

scholarly journals EFFECTIVENESS OF ACAMPROSATE FOR TINNITUS: A SYSTEMATIC REVIEW AND META-ANALYSIS OF CLINICAL TRIALS

2021 ◽  
Author(s):  
Osmar Clayton Person ◽  
Fernando Veiga Angelico Junior ◽  
Rodrigo Lima de Godoy Santos ◽  
William Marasini de Rezende ◽  
Maria Fernanda Giusti ◽  
...  
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Randomized Clinical Trials ◽  
Meta Analysis ◽  
Medical Science ◽  
Placebo Response ◽  
Cochrane Central Register ◽  
Significant Difference ◽  
Tinnitus Treatment

Introduction: The effectiveness of tinnitus treatment represents a huge gap in the medical science. Acamprosate is a glutamatergic antagonist drug and GABA-agonist that could be used to control tinnitus due to its action on peripheral and central neurotransmission. Purpose: To assess the effectiveness of acamprosate in the treatment of tinnitus. Material and Methods: This is a systematic review and we searched for randomized clinical trials linking acamprosate to tinnitus in six databases: Cochrane - Central Register of Controlled Trials - CENTRAL (2021), PUBMED (1966-2021), EMBASE (1974-2021), IBECS (1982-2021), QINSIGHT (2021) and SCOPUS (2021). Two researchers independently extracted the data and assessed the quality of the studies. Results: Two trials involving 121 patients were included. The methodological quality of these studies was low. Both studies evaluated as primary outcome the efficacy of acamprosate in improving tinnitus. The meta-analysis by random model resulted in no significant difference between the groups treated with acamprosate and placebo (RR = 3,69, 95% CI 0,87-15,62; p=0,08), considering tinnitus improvement. Conclusions: There is no evidence that acamprosate is effective for tinnitus treatment. We recommend new trials using rigorous methodology. Randomization and blinding should be of the highest quality, given the subjective nature of tinnitus and the strong likelihood of a placebo response. The CONSORT statement should be used in the design and reporting of future studies.

Sign in / Sign up

Export Citation Format

Share Document