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Pediatric Research Jan 2017A potential larger perceived placebo effect in children compared with adults could influence the detection of the treatment effect and the extrapolation of the treatment... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
A potential larger perceived placebo effect in children compared with adults could influence the detection of the treatment effect and the extrapolation of the treatment benefit from adults to children. This study aims to explore this potential difference, using a meta-epidemiological approach.
METHODS
A systematic review of the literature was done to identify trials included in meta-analyses evaluating a drug intervention with separate data for adults and children. The standardized mean change and the proportion of responders (binary outcomes) were used to calculate the perceived placebo effect. A meta-regression analysis was conducted to test for the difference between adults and children of the perceived placebo effect.
RESULTS
For binary outcomes, the perceived placebo effect was significantly more favorable in children compared with adults (β = 0.13; P = 0.001). Parallel group trials (β = -1.83; P < 0.001), subjective outcomes (β = -0.76; P < 0.001), and the disease type significantly influenced the perceived placebo effect.
CONCLUSION
The perceived placebo effect is different between adults and children for binary outcomes. This difference seems to be influenced by the design, the disease, and outcomes. Calibration of new studies for children should consider cautiously the placebo effect in children.
Topics: Adult; Age Factors; Child; Humans; Perception; Placebo Effect; Randomized Controlled Trials as Topic; Regression Analysis
PubMed: 27648807
DOI: 10.1038/pr.2016.181 -
The Cochrane Database of Systematic... Feb 2022Transient tachypnoea of the newborn (TTN) is characterised by tachypnoea and signs of respiratory distress. It is caused by delayed clearance of lung fluid at birth. TTN... (Review)
Review
BACKGROUND
Transient tachypnoea of the newborn (TTN) is characterised by tachypnoea and signs of respiratory distress. It is caused by delayed clearance of lung fluid at birth. TTN typically appears within the first two hours of life in term and late preterm newborns. Although it is usually a self-limited condition, admission to a neonatal unit is frequently required for monitoring, the provision of respiratory support, and drugs administration. These interventions might reduce respiratory distress during TTN and enhance the clearance of lung liquid. The goals are reducing the effort required to breathe, improving respiratory distress, and potentially shortening the duration of tachypnoea. However, these interventions might be associated with harm in the infant.
OBJECTIVES
The aim of this overview was to evaluate the benefits and harms of different interventions used in the management of TTN.
METHODS
We searched the Cochrane Database of Systematic Reviews on 14 July 2021 for ongoing and published Cochrane Reviews on the management of TTN in term (> 37 weeks' gestation) or late preterm (34 to 36 weeks' gestation) infants. We included all published Cochrane Reviews assessing the following categories of interventions administered within the first 48 hours of life: beta-agonists (e.g. salbutamol and epinephrine), corticosteroids, diuretics, fluid restriction, and non-invasive respiratory support. The reviews compared the above-mentioned interventions to placebo, no treatment, or other interventions for the management of TTN. The primary outcomes of this overview were duration of tachypnoea and the need for mechanical ventilation. Two overview authors independently checked the eligibility of the reviews retrieved by the search and extracted data from the included reviews using a predefined data extraction form. Any disagreements were resolved by discussion with a third overview author. Two overview authors independently assessed the methodological quality of the included reviews using the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews) tool. We used the GRADE approach to assess the certainty of evidence for effects of interventions for TTN management. As all of the included reviews reported summary of findings tables, we extracted the information already available and re-graded the certainty of evidence of the two primary outcomes to ensure a homogeneous assessment. We provided a narrative summary of the methods and results of each of the included reviews and summarised this information using tables and figures.
MAIN RESULTS
We included six Cochrane Reviews, corresponding to 1134 infants enrolled in 18 trials, on the management of TTN in term and late preterm infants, assessing salbutamol (seven trials), epinephrine (one trial), budesonide (one trial), diuretics (two trials), fluid restriction (four trials), and non-invasive respiratory support (three trials). The quality of the included reviews was high, with all of them fulfilling the critical domains of the AMSTAR 2. The certainty of the evidence was very low for the primary outcomes, due to the imprecision of the estimates (few, small included studies) and unclear or high risk of bias. Salbutamol may reduce the duration of tachypnoea compared to placebo (mean difference (MD) -16.83 hours, 95% confidence interval (CI) -22.42 to -11.23, 2 studies, 120 infants, low certainty evidence). We did not identify any review that compared epinephrine or corticosteroids to placebo and reported on the duration of tachypnoea. However, one review reported on "trend of normalisation of respiratory rate", a similar outcome, and found no differences between epinephrine and placebo (effect size not reported). The evidence is very uncertain regarding the effect of diuretics compared to placebo (MD -1.28 hours, 95% CI -13.0 to 10.45, 2 studies, 100 infants, very low certainty evidence). We did not identify any review that compared fluid restriction to standard fluid rates and reported on the duration of tachypnoea. The evidence is very uncertain regarding the effect of continuous positive airway pressure (CPAP) compared to free-flow oxygen therapy (MD -21.1 hours, 95% CI -22.9 to -19.3, 1 study, 64 infants, very low certainty evidence); the effect of nasal high-frequency (oscillation) ventilation (NHFV) compared to CPAP (MD -4.53 hours, 95% CI -5.64 to -3.42, 1 study, 40 infants, very low certainty evidence); and the effect of nasal intermittent positive pressure ventilation (NIPPV) compared to CPAP on duration of tachypnoea (MD 4.30 hours, 95% CI -19.14 to 27.74, 1 study, 40 infants, very low certainty evidence). Regarding the need for mechanical ventilation, the evidence is very uncertain for the effect of salbutamol compared to placebo (risk ratio (RR) 0.60, 95% CI 0.13 to 2.86, risk difference (RD) 10 fewer, 95% CI 50 fewer to 30 more per 1000, 3 studies, 254 infants, very low certainty evidence); the effect of epinephrine compared to placebo (RR 0.67, 95% CI 0.08 to 5.88, RD 70 fewer, 95% CI 460 fewer to 320 more per 1000, 1 study, 20 infants, very low certainty evidence); and the effect of corticosteroids compared to placebo (RR 0.52, 95% CI 0.05 to 5.38, RD 40 fewer, 95% CI 170 fewer to 90 more per 1000, 1 study, 49 infants, very low certainty evidence). We did not identify a review that compared diuretics to placebo and reported on the need for mechanical ventilation. The evidence is very uncertain regarding the effect of fluid restriction compared to standard fluid administration (RR 0.73, 95% CI 0.24 to 2.23, RD 20 fewer, 95% CI 70 fewer to 40 more per 1000, 3 studies, 242 infants, very low certainty evidence); the effect of CPAP compared to free-flow oxygen (RR 0.30, 95% CI 0.01 to 6.99, RD 30 fewer, 95% CI 120 fewer to 50 more per 1000, 1 study, 64 infants, very low certainty evidence); the effect of NIPPV compared to CPAP (RR 4.00, 95% CI 0.49 to 32.72, RD 150 more, 95% CI 50 fewer to 350 more per 1000, 1 study, 40 infants, very low certainty evidence); and the effect of NHFV versus CPAP (effect not estimable, 1 study, 40 infants, very low certainty evidence). Regarding our secondary outcomes, duration of hospital stay was the only outcome reported in all of the included reviews. One trial on fluid restriction reported a lower duration of hospitalisation in the restricted-fluids group, but with very low certainty of evidence. The evidence was very uncertain for the effects on secondary outcomes for the other five reviews. Data on potential harms were scarce, as all of the trials were underpowered to detect possible increases in adverse events such as pneumothorax, arrhythmias, and electrolyte imbalances. No adverse effects were reported for salbutamol; however, this medication is known to carry a risk of tachycardia, tremor, and hypokalaemia in other settings.
AUTHORS' CONCLUSIONS
This overview summarises the evidence from six Cochrane Reviews of randomised trials regarding the effects of postnatal interventions in the management of TTN. Salbutamol may reduce the duration of tachypnoea slightly. We are uncertain as to whether salbutamol reduces the need for mechanical ventilation. We are uncertain whether epinephrine, corticosteroids, diuretics, fluid restriction, or non-invasive respiratory support reduces the duration of tachypnoea and the need for mechanical ventilation, due to the extremely limited evidence available. Data on harms were lacking.
Topics: Humans; Infant; Infant, Newborn; Infant, Premature; Intermittent Positive-Pressure Ventilation; Oxygen Inhalation Therapy; Systematic Reviews as Topic; Transient Tachypnea of the Newborn
PubMed: 35199848
DOI: 10.1002/14651858.CD013563.pub2 -
Rheumatology (Oxford, England) Apr 2022To determine the placebo response rate in PsA randomized clinical trials (RCTs), its contributing factors and impact on the effect size of active treatments. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To determine the placebo response rate in PsA randomized clinical trials (RCTs), its contributing factors and impact on the effect size of active treatments.
METHODS
We searched multiple databases, from inception to 20 December 2020, for placebo-controlled RCTs in PsA. We used a random-effects meta-analysis to pool the response rates for the ACR20 criteria in the placebo arm, determined the risk difference for treatment vs placebo, and used meta-regression to determine the factors associated with placebo response rates. The risk of bias was assessed in duplicate. The study protocol was registered with PROSPERO: CRD42021226000.
RESULTS
We included 42 RCTs (5050 patients receiving placebo) published between 2000 and 2020. The risk of bias was low in 28 trials, high in four, and with some concerns in 10. The pooled placebo response rate was 20.3% (95% CI: 18.6%, 22.1%; predicted intervals, 11.7-29.0%), with significant between-trial heterogeneity (I2 = 56.8%, P < 0.005). The pooled risk difference for treatment vs placebo was 27% (95% CI: 24%, 31%). In the multivariable meta-regression, there was a 15% (95% CI: 2.9%, 29.8%) increase in the odds of achieving the placebo response for each 5-year increment in publication year (P = 0.016). In addition, the active treatment risk difference decreased for every 5-year increment in publication year (β = -0.053, 95% CI: -0.099, -0.007; P = 0.024) but was not associated with the placebo response.
CONCLUSION
Despite increasing over time, the placebo response for ACR20 in PsA RCTs was not associated with the active treatment effect size.
Topics: Arthritis, Psoriatic; Humans; Placebo Effect
PubMed: 34664615
DOI: 10.1093/rheumatology/keab774 -
Journal of Pain Research 2021The literature lacks information about the characteristics of the placebo effect following sham spine procedures for chronic low back pain. We aim to evaluate the effect... (Review)
Review
BACKGROUND
The literature lacks information about the characteristics of the placebo effect following sham spine procedures for chronic low back pain. We aim to evaluate the effect using pain score data from the sham arms of published trials.
METHODS
Relevant trials were selected and reviewed. Baseline and post-procedure pain scores were collected. Each follow up pain score was considered an episode and compared to its baseline for significance. Patients and episodes were pooled and analyzed using three parameters: patient reported outcome measures (PROMs) (Oswestry Disability Index [ODI], Visual Analog Scale [VAS], Numerical Rating Scale [NRS] and Short Form-36 [SF]), anatomical targets (disc, facet, sacroiliac joint [SIJ], ramus communicans nerve [RCN], basivertebral nerve [BVN], and caudal) and follow up periods (early: 0-2, intermediate: >2-4 and late: >4-6) in months. The percentage of pooled patients in the episodes that had significant reduction in pain scores was termed placebo effect. The outcome was defining the magnitude of the placebo effect and determining if it was influenced by the three parameters.
RESULTS
Seventeen studies that reported 535 patients and 55 pain scoring episodes were considered eligible. Significant reduction in pain scores was reported in 21 episodes. The overall placebo effect among the patients during the studied period was 53.2%. The rate ranged according to PROMs from 42.4% to 72.1%, anatomical targets from 11.1% to 100% and follow up periods from 47.9% to 59%. The placebo effect differed significantly between the various domains in the three parameters.
CONCLUSION
Placebo effect was observed in nearly half of the patients during the first 6 months following a sham spine procedure. The effect was influenced by utilized PROMs, anatomical target and follow up period. The findings should be considered in the design of new sham spine procedure trials. Further research is required to delineate the effect of bias on the findings.
PubMed: 34616178
DOI: 10.2147/JPR.S317697 -
Pain Physician 2016There is conflicting evidence from previous qualitative reviews on the effect of vitamin D supplementation on pain. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
There is conflicting evidence from previous qualitative reviews on the effect of vitamin D supplementation on pain.
OBJECTIVE
To determine with quantitative methods if vitamin D supplementation lowers pain levels.
STUDY DESIGN
Quantitative meta-analysis of published randomized controlled trials (RCTs).
SETTING
This meta-analysis examined all studies involving the effect of vitamin D supplementation on pain score.
METHOD
Electronic sources (Medline, Embase, Cochrane Central Register of Controlled Trials, clinical trials website, and Google scholar) were systematically searched for RCTs of vitamin D supplementation and pain from inception of each database to October 2015.
RESULTS
Nineteen RCTs with 3,436 participants (1,780 on vitamin D supplementation and 1,656 on placebo) were included in the meta-analysis. For the primary outcome (mean change in pain score from baseline to final follow-up), 8 trials with 1,222 participants on vitamin D and 1,235 on placebo reported a significantly greater mean decrease in pain score for the vitamin D group compared to placebo (mean difference -0.57, 95% CI: -1.00 to -0.15, P = 0.007). The effect from vitamin D was greater in patients recruited with pre-existing pain (P-value for interaction = 0.03). Fourteen studies (1,548 on vitamin D, 1,430 on placebo) reported the mean pain score at final follow-up outcome, and no statistical difference was observed (mean difference -0.06, 95%CI: -0.44 to 0.33, P = 0.78). In 4 studies which reported pain improvement (209 on vitamin D, 146 on placebo), the effect size although not significant, shows participants in the vitamin D supplementation group were more likely to report pain improvement compared with the placebo group (relative risk 1.38, 95%CI: 0.93 to 2.05, P = 0.11).
LIMITATIONS
Only a few studies reported the mean score change from baseline to final follow-up, and we do not have enough data to determine any modifying effect of baseline vitamin D status and different doses of vitamin D supplementation on pain.
CONCLUSION
A significantly greater mean decrease in pain score (primary outcome) was observed with vitamin D supplementation compared with placebo in people with chronic pain. These results suggest that vitamin D supplementation could have a role in the management of chronic pain.
KEY WORDS
Meta-analysis, pain, randomized controlled trials, vitamin D supplementation.
Topics: Dietary Supplements; Humans; Pain; Randomized Controlled Trials as Topic; Vitamin D; Vitamins
PubMed: 27676659
DOI: No ID Found -
European Journal of Pain (London,... Oct 2021The current treatments of primary musculoskeletal low back pain (LBP) have a low to moderate efficacy, which might be improved by looking at the contribution of placebo... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND OBJECTIVE
The current treatments of primary musculoskeletal low back pain (LBP) have a low to moderate efficacy, which might be improved by looking at the contribution of placebo effects. However, the size of true placebo effects in LBP is unknown. Therefore, a systematic review and meta-analysis were executed of randomized controlled trials investigating placebo effects in LBP.
DATABASES AND DATA TREATMENT
The study protocol was registered in the international prospective register of systematic reviews Prospero (CRD42019148745). A literature search (in PubMed, Embase, The Cochrane Library, CINAHL and PsycINFO) up to 2021 February 16th yielded 2,423 studies. Two independent reviewers assessed eligibility and risk of bias.
RESULTS
Eighteen studies were eligible for the systematic review and 5 for the meta-analysis. Fourteen of the 18 studies were clinical treatment studies, and 4 were experimental studies specifically assessing placebo effects. The clinical treatment studies provided varying evidence for placebo effects in chronic LBP but insufficient evidence for acute and subacute LBP. Most experimental studies investigating chronic LBP revealed significant placebo effects. The meta-analysis of 5 treatment studies investigating chronic LBP depicted a significant moderate effect size of placebo for pain intensity (SMD = 0.57) and disability (SMD = 0.52).
CONCLUSIONS
This review shows a significant contribution of placebo effects to chronic LBP symptom relief in clinical and experimental conditions. The meta-analysis revealed that placebo effects can influence chronic LBP intensity and disability. However, additional studies are required for more supporting evidence and evidence for placebo effects in acute or subacute LBP.
SIGNIFICANCE
This systematic review and meta-analysis provides evidence of true placebo effects in low back pain (LBP). It shows a significant contribution of placebo effects to chronic LBP symptom relief. The results highlight the importance of patient- and context-related factors in fostering treatment effects in this patient group. New studies could provide insight into the potential value of actively making use of placebo effects in clinical practice.
Topics: Chronic Pain; Humans; Low Back Pain; Placebo Effect
PubMed: 34051018
DOI: 10.1002/ejp.1811 -
Oral Diseases Apr 2014Placebo controls play a critical role in the evaluation of any pharmacotherapy. This review surveys the placebo arm in 12 randomized controlled trials (RCTs)... (Review)
Review
Placebo controls play a critical role in the evaluation of any pharmacotherapy. This review surveys the placebo arm in 12 randomized controlled trials (RCTs) investigating burning mouth syndrome (BMS) and documents a positive placebo response in 6 of them. On average, treatment with placebos produced a response that was 72% as large as the response to active drugs. The lack of homogeneity in the use of placebos adds to the difficulty in comparing results and aggregating data. Future RCTs investigating BMS would benefit from larger sample sizes, adequate follow-up periods, and use of a standard placebo.
Topics: Burning Mouth Syndrome; Humans; Placebo Effect; Randomized Controlled Trials as Topic; Treatment Outcome
PubMed: 24164777
DOI: 10.1111/odi.12192 -
The American Journal of Geriatric... Sep 2017Increasing placebo effect sizes over time have been reported in randomized controlled trials (RCTs) for outcomes related to psychiatric symptoms. The Neuropsychiatric... (Meta-Analysis)
Meta-Analysis Review
Variation in Placebo Effect Sizes in Clinical Trials of Oral Interventions for Management of the Behavioral and Psychological Symptoms of Dementia (BPSD): A Systematic Review and Meta-Analysis.
Increasing placebo effect sizes over time have been reported in randomized controlled trials (RCTs) for outcomes related to psychiatric symptoms. The Neuropsychiatric Inventory (NPI) is a key outcome measure in clinical trials of the behavioral and psychological symptoms of dementia (BPSD). Accurate placebo effect size estimates for NPI are needed for sample size calculations in order to adequately power future studies. This study investigated variation in placebo effect sizes for NPI in RCTs testing oral interventions for BPSD. A search of PubMed was conducted in April 2016 for two-armed, double-blinded, placebo-controlled RCTs testing any oral intervention for management of BPSD using the NPI. Meta-analysis was conducted of baseline versus end of treatment placebo group data of included studies. Twenty-five RCTs published from 2000 to 2015 were included. Substantial variation in placebo effect sizes was detected. Participants in placebo groups showed greater improvements in recent studies compared with earlier studies. Subgroup analyses indicated robustness of this finding. From 2000 to 2008 there was no significant change in total NPI scores within placebo groups (12 studies; 1,056 participants), whereas from 2009 to 2015 there was significant improvement (mean difference: -2.68; 95% confidence interval: -4.38, -0.99; z = 3.10; p = 0.002, random effects; I = 76%; 13 studies; 1,170 participants). This increase in NPI effect sizes in placebo groups has important implications for power calculations for future clinical trials of BPSD. Effect size estimates for NPI need to be based on more recent studies.
Topics: Dementia; Humans; Placebo Effect; Problem Behavior; Randomized Controlled Trials as Topic; Sample Size
PubMed: 28363357
DOI: 10.1016/j.jagp.2017.02.022 -
Cephalalgia : An International Journal... Feb 2021To evaluate the association between the degree of response to placebo in migraine studies and the observed difference between drug and placebo across studies of...
The relation between the placebo response, observed treatment effect, and failure to meet primary endpoint: A systematic review of clinical trials of preventative pharmacological migraine treatments.
OBJECTIVE
To evaluate the association between the degree of response to placebo in migraine studies and the observed difference between drug and placebo across studies of preventative treatments for migraine.
METHODS
A systematic review was performed using MEDLINE and the Cochrane Central Register of Controlled Clinical Trials from January 1988 to June 2019. Randomized, double-blind, parallel-group, placebo-controlled trials on oral or injection preventative treatments for migraine were included. Single- and multi-variable linear regression analyses were performed on the placebo-subtracted response rate (i.e. placebo responders subtracted from active responders), and the proportion of placebo responders. Fisher's exact tests were performed on the level of placebo response and the success in meeting the study's primary endpoint.
RESULTS
After adjusting for route of administration and number of randomized subjects, there was a statistically significant association between the proportion of patients who were placebo responders and the placebo-subtracted response rate (b = -0.27, = 0.02). There was a statistically significant difference in trial success rate (60%) between studies with ≤20% placebo responders and studies with > 30% placebo responders ( = 0.03).
CONCLUSION
Considering the detrimental impact that high placebo response can have on clinical trials, it is imperative to find effective solutions to decrease the placebo response and increase assay sensitivity.
Topics: Double-Blind Method; Humans; Migraine Disorders; Placebo Effect; Randomized Controlled Trials as Topic
PubMed: 32960658
DOI: 10.1177/0333102420960020 -
Frontiers in Psychiatry 2020The present systematic review aims to analyze the evidence about the influence of placebo effect on craving and cognitive performance in alcohol, caffeine, and nicotine...
OBJECTIVE
The present systematic review aims to analyze the evidence about the influence of placebo effect on craving and cognitive performance in alcohol, caffeine, and nicotine consumers.
METHODS
Relevant studies were identified Pubmed, Web of Science, and Scopus databases (up to March 2020). Only those papers published between 2009 and 2019 were searched.
RESULTS
Of the 115 preliminary papers, 8 studies of database search and 9 of the manual search were finally included in this review. Findings showed that while alcohol expectancies increased craving, caffeine and nicotine expectancies tend to decrease it. Alcohol expectancies caused similar or slower reaction time when alcohol was not consumed, impairments on inhibitory control (especially after alcohol consumption) and similar post-error slowing. The effect of caffeine and nicotine on reaction time has not been elucidated yet, however, caffeine expectancies have been shown to improve accuracy and the attentional filtering of distracting stimuli.
CONCLUSIONS
Alcohol, caffeine, and nicotine expectancies play an important role on craving. Although expectancies produce an effect on cognitive performance, caffeine and nicotine beliefs show an ambiguous impact on reaction time. Only the influence of alcohol expectancies on reaction time has been clarified. Furthermore, caffeine beliefs enhance accuracy.
PubMed: 33005155
DOI: 10.3389/fpsyt.2020.00849