scholarly journals Number Of Clinical Trial Study Sites Impacts Observed Treatment Effect Size: An Analysis Of Randomized Controlled Trials Of Opioids For Chronic Pain

2019 ◽  
Vol Volume 12 ◽  
pp. 3161-3165
Author(s):  
Diana S Meske ◽  
Ben J Vaughn ◽  
Ernest A Kopecky ◽  
Nathaniel Katz
Methodology ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 41-60
Author(s):  
Shahab Jolani ◽  
Maryam Safarkhani

Abstract. In randomized controlled trials (RCTs), a common strategy to increase power to detect a treatment effect is adjustment for baseline covariates. However, adjustment with partly missing covariates, where complete cases are only used, is inefficient. We consider different alternatives in trials with discrete-time survival data, where subjects are measured in discrete-time intervals while they may experience an event at any point in time. The results of a Monte Carlo simulation study, as well as a case study of randomized trials in smokers with attention deficit hyperactivity disorder (ADHD), indicated that single and multiple imputation methods outperform the other methods and increase precision in estimating the treatment effect. Missing indicator method, which uses a dummy variable in the statistical model to indicate whether the value for that variable is missing and sets the same value to all missing values, is comparable to imputation methods. Nevertheless, the power level to detect the treatment effect based on missing indicator method is marginally lower than the imputation methods, particularly when the missingness depends on the outcome. In conclusion, it appears that imputation of partly missing (baseline) covariates should be preferred in the analysis of discrete-time survival data.


Hernia ◽  
2021 ◽  
Author(s):  
Alberto Aiolfi ◽  
Marta Cavalli ◽  
Simona Del Ferraro ◽  
Livia Manfredini ◽  
Francesca Lombardo ◽  
...  

Abstract Purpose To examine the updated evidence on safety, effectiveness, and outcomes of the totally extraperitoneal (TEP) versus the laparoscopic transabdominal preperitoneal (TAPP) repair and to explore the timely tendency variations favoring one treatment over another. Methods Systematic review and trial sequential analysis (TSA) of randomized controlled trials (RCTs). MEDLINE, Scopus, Web of Science, Cochrane Central Library, and ClinicalTrials.gov were consulted. Risk Ratio (RR), weighted mean difference (WMD), and 95% confidence intervals (CI) were used as pooled effect size measures. Results Fifteen RCTs were included (1359 patients). Of these, 702 (51.6%) underwent TAPP and 657 (48.4%) TEP repair. The age of the patients ranged from 18 to 92 years and 87.9% were males. The estimated pooled RR for hernia recurrence (RR = 0.83; 95% CI 0.35–1.96) and chronic pain (RR = 1.51; 95% CI 0.54–4.22) were similar for TEP vs. TAPP. The TSA shows a cumulative z-curve without crossing the monitoring boundaries line (Z = 1.96), thus supporting true negative results while the information size was calculated as adequate for both outcomes. No significant differences were found in term of early postoperative pain, operative time, wound-related complications, hospital length of stay, return to work/daily activities, and costs. Conclusions TEP and TAPP repair seems comparable in terms of postoperative hernia recurrence and chronic pain. The cumulative evidence and information size are sufficient to provide a conclusive evidence on recurrence and chronic pain. Similar trials or meta-analyses seem unlikely to show diverse results and should be discouraged.


2015 ◽  
Vol 101 (1) ◽  
pp. e1.66-e1
Author(s):  
Rym Boulkedid ◽  
Armiya Yousouf Abdou ◽  
Emilie Desselas ◽  
Marlène Monegat ◽  
Corinne Alberti ◽  
...  

BackgroundApproximately 15 to 30% of children and adolescents suffer from daily pain persistent over more than 3 months and there is evidence supporting that the prevalence of chronic pain is steadily increasing in this population. Chronic pain is known to have a negative impact on children's development and social behaviour, leading often to severe psychological distress and physical disability. We reviewed medical literature to assess the characteristics and quality of randomized controlled trials (RCTs) on pharmacological and non-pharmacological therapies in chronic and recurrent pain in the paediatric population.MethodsWe performed a systematic search of PubMed, Embase and the Cochrane Library up to March 2014. Bibliographies of relevant articles were also hand-searched. We included all RCTs that involved children and adolescents (age 0 to 18 years) and evaluated the use of a pharmacological agent or a non-pharmacological approach in the context of chronic or recurrent pain. The latter was defined as pain persisting for more than 3 months. Methodological quality was evaluated using the Cochrane Risk of Bias Tool. Two reviewers independently assessed studies for inclusion and evaluated methodological quality.ResultsA total of 52 randomized controlled trials were selected and included in the analysis. The majority were conducted in single hospital institutions, with no information on study funding. Median sample size was 45 (34–57) participants. Almost 50% of the RCTs included both adults and children with a median age at inclusion of 13 years. Non-pharmacological approaches were more commonly tested whereas evaluation of pharmacological agents concerned less than 30% of RCTs. Abdominal pain and headache were the most common types of chronic pain experienced among trial participants. Overall, the methodological quality was poor and did not parallel the number of RCTs that increased over the years. The risk of bias was high or unclear in 70% of the trials.ConclusionsThis is the first systematic review of RCTs conducted to evaluate pharmacological and non-pharmacological therapies in chronic and recurrent pain in children and adolescents. Although, management of pain in adults has significantly improved over the years due to the evaluation of numerous analgesic therapies, our results highlight the existing knowledge gap with regards to children and adolescents. Therapeutic strategies, in particular pharmacological agents, applied to relieve chronic or recurrent pain in children and adolescents are not evaluated through high quality RCTs. The need to improve analgesic therapy in children and adolescents with chronic pain is still unmet. We discuss possible research constraints and challenges related to this fact as well as adequate methodologies to circumvent them.


2021 ◽  
pp. 174077452098487
Author(s):  
Brian Freed ◽  
Brian Williams ◽  
Xiaolu Situ ◽  
Victoria Landsman ◽  
Jeehyoung Kim ◽  
...  

Background: Blinding aims to minimize biases from what participants and investigators know or believe. Randomized controlled trials, despite being the gold standard to evaluate treatment effect, do not generally assess the success of blinding. We investigated the extent of blinding in back pain trials and the associations between participant guesses and treatment effects. Methods: We did a review with PubMed/OvidMedline, 2000–2019. Eligibility criteria were back pain trials with data available on treatment effect and participants’ guess of treatment. For blinding, blinding index was used as chance-corrected measure of excessive correct guess (0 for random guess). For treatment effects, within- or between-arm effect sizes were used. Analyses of investigators’ guess/blinding or by treatment modality were performed exploratorily. Results: Forty trials (3899 participants) were included. Active and sham treatment groups had mean blinding index of 0.26 (95% confidence interval: 0.12, 0.41) and 0.01 (−0.11, 0.14), respectively, meaning 26% of participants in active treatment believed they received active treatment, whereas only 1% in sham believed they received sham treatment, beyond chance, that is, random guess. A greater belief of receiving active treatment was associated with a larger within-arm effect size in both arms, and ideal blinding (namely, “random guess,” and “wishful thinking” that signifies both groups believing they received active treatment) showed smaller effect sizes, with correlation of effect size and summary blinding indexes of 0.35 ( p = 0.028) for between-arm comparison. We observed uniformly large sham treatment effects for all modalities, and larger correlation for investigator’s (un)blinding, 0.53 ( p = 0.046). Conclusion: Participants in active treatments in back pain trials guessed treatment identity more correctly, while those in sham treatments tended to display successful blinding. Excessive correct guesses (that could reflect weaker blinding and/or noticeable effects) by participants and investigators demonstrated larger effect sizes. Blinding and sham treatment effects on back pain need due consideration in individual trials and meta-analyses.


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