Assessing blinding in trials of psychiatric disorders: a meta-analysis based on blinding index.
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SUBMITTER: Freed B
PROVIDER: S-EPMC4183143 | biostudies-literature | 2014 Oct
REPOSITORIES: biostudies-literature
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Assessing blinding in trials of psychiatric disorders: a meta-analysis based on blinding index.
Freed Brian B Assall Oliver Paul OP Panagiotakis Gary G Bang Heejung H Park Jongbae J JJ Moroz Alex A Baethge Christopher C
Psychiatry research 20140522 2
The assessment of blinding in RCTs is rarely performed. Currently most studies that do report data on evaluation of blinding merely report percentages of correct guessing, not taking into account correct guessing by chance. Blinding assessment using the blinding index (BI) has never been performed in a systematic review on studies of major psychiatric disorders. This study is a systematic review of psychiatric randomized control trials using the BI as a chance-corrected measurement of blinding, ...[more]
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Project description:BackgroundBlinding is a cornerstone of treatment evaluation. Blinding is more difficult to obtain in trials assessing nonpharmacological treatment and frequently relies on "creative" (nonstandard) methods. The purpose of this study was to systematically describe the strategies used to obtain blinding in a sample of randomized controlled trials of nonpharmacological treatment.Methods and findingsWe systematically searched in Medline and the Cochrane Methodology Register for randomized controlled trials (RCTs) assessing nonpharmacological treatment with blinding, published during 2004 in high-impact-factor journals. Data were extracted using a standardized extraction form. We identified 145 articles, with the method of blinding described in 123 of the reports. Methods of blinding of participants and/or health care providers and/or other caregivers concerned mainly use of sham procedures such as simulation of surgical procedures, similar attention-control interventions, or a placebo with a different mode of administration for rehabilitation or psychotherapy. Trials assessing devices reported various placebo interventions such as use of sham prosthesis, identical apparatus (e.g., identical but inactivated machine or use of activated machine with a barrier to block the treatment), or simulation of using a device. Blinding participants to the study hypothesis was also an important method of blinding. The methods reported for blinding outcome assessors relied mainly on centralized assessment of paraclinical examinations, clinical examinations (i.e., use of video, audiotape, photography), or adjudications of clinical events.ConclusionsThis study classifies blinding methods and provides a detailed description of methods that could overcome some barriers of blinding in clinical trials assessing nonpharmacological treatment, and provides information for readers assessing the quality of results of such trials.
| S-EPMC1800311 | biostudies-literature
Project description:Summary Background In double-blind randomized controlled trials (RCTs) of antidepressants, blinding can be broken due to the apparent side effects, and unsuccessful blinding can lead to overestimation of effect sizes. New generation antidepressants with less severe side effects may be less susceptible to broken blinding. However, successfulness of blinding in new generation antidepressant trials and its influence on trial effect size estimates remain unclear. Methods Extending a previous systematic review assessing blinding successfulness in psychiatric trials (2000-2010), we searched PubMed/Medline for double-blinded antidepressant RCTs (2010-2020) for trials assessing blinding success. Our primary outcome was the degree of blinding successfulness, measured as kappa statistics between guesses and true allocations. We used random-effects meta-analysis to synthesize studies. We used meta-regression and Pearson's r to examine the relationship between blinding success and effect sizes. This study is registered with PROSPERO (CRD42021249973). Findings Among 154 eligible studies, 11 (7·1%) contained information on blinding assessment between 2010 and 2020. Five studies were added from the previous review, and altogether nine of the 16 studies provided usable data. Agreement in individual studies ranged from κ=-0·14 to 0·38. The summary agreement between guesses and the truth was 0·21 (95% CI: 0·14 to 0·28) among patients and 0·17 (95% CI: 0·05 to 0·30) among assessors. Blinding success was not associated with effect size (patients: r = 0·37, p = 0·32; assessors: r = 0·28; p = 0·72). Meta-regression also failed to find a significant relationship between blinding success and depression effect sizes (β=0·06, p = 0·09). Interpretation Less than 10% of the antidepressant RCTs reported blinding assessment. The results in new generation antidepressant trials indicated that patients and assessors were unlikely to be able to judge treatment allocation. There was little evidence that the extent of unblinding biased the effect size estimates of new generation antidepressants. Funding None.
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Project description:BackgroundBlinding is a cornerstone of therapeutic evaluation because lack of blinding can bias treatment effect estimates. An inventory of the blinding methods would help trialists conduct high-quality clinical trials and readers appraise the quality of results of published trials. We aimed to systematically classify and describe methods to establish and maintain blinding of patients and health care providers and methods to obtain blinding of outcome assessors in randomized controlled trials of pharmacologic treatments.Methods and findingsWe undertook a systematic review of all reports of randomized controlled trials assessing pharmacologic treatments with blinding published in 2004 in high impact-factor journals from Medline and the Cochrane Methodology Register. We used a standardized data collection form to extract data. The blinding methods were classified according to whether they primarily (1) established blinding of patients or health care providers, (2) maintained the blinding of patients or health care providers, and (3) obtained blinding of assessors of the main outcomes. We identified 819 articles, with 472 (58%) describing the method of blinding. Methods to establish blinding of patients and/or health care providers concerned mainly treatments provided in identical form, specific methods to mask some characteristics of the treatments (e.g., added flavor or opaque coverage), or use of double dummy procedures or simulation of an injection. Methods to avoid unblinding of patients and/or health care providers involved use of active placebo, centralized assessment of side effects, patients informed only in part about the potential side effects of each treatment, centralized adapted dosage, or provision of sham results of complementary investigations. The methods reported for blinding outcome assessors mainly relied on a centralized assessment of complementary investigations, clinical examination (i.e., use of video, audiotape, or photography), or adjudication of clinical events.ConclusionsThis review classifies blinding methods and provides a detailed description of methods that could help trialists overcome some barriers to blinding in clinical trials and readers interpret the quality of pharmacologic trials.
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Project description:BackgroundAmong all diseases globally, mental illnesses are one of the major causes of burden. As many people are resistant to conventional evidence-based treatments, there is an unmet need for the implementation of novel mental health treatments. Efforts to increase the effectiveness and benefits of evidence-based psychotherapy in psychiatry have led to the emergence of virtual reality (VR)-based interventions. These interventions have shown a wide range of advantages over conventional psychotherapies. Currently, VR-based interventions have been developed mainly for anxiety-related disorders; however, they are also used for developmental disorders, severe mental disorders, and neurocognitive disorders.ObjectiveThis meta-review aims to summarize the current state of evidence on the efficacy of VR-based interventions for various psychiatric disorders by evaluating the quality of evidence provided by meta-analytical studies.MethodsA systematic search was performed using the following electronic databases: PubMed, PsycINFO, Web of Science, and Google Scholar (any time until February 2020). Meta-analyses were included as long as they quantitatively examined the efficacy of VR-based interventions for symptoms of a psychiatric disorder. To avoid overlap among meta-analyses, for each subanalysis included within this meta-review, only one analysis provided from one meta-analysis was selected based on the best quality of evidence.ResultsThe search retrieved 11 eligible meta-analyses. The quality of evidence varied from very low to moderate quality. Several reasons account for the lower quality evidence, such as a limited number of randomized controlled trials, lack of follow-up analysis or control group, and the presence of heterogeneity and publication bias. Nonetheless, evidence has shown that VR-based interventions for anxiety-related disorders display overall medium-to-large effects when compared with inactive controls but no significant difference when compared with standard evidence-based approaches. Preliminary data have highlighted that such effects appear to be sustained in time, and subjects may fare better than active controls. Neurocognitive disorders also appear to improve with VR-based approaches, with small effects being found for various clinical outcomes (eg, cognition, emotion). Finally, there are insufficient data to classify VR-based interventions as an evidence-based practice for social skills training in neurodevelopmental disorders and compliance among patients with schizophrenia.ConclusionsVR provides unlimited opportunities by tailoring approaches to specific complex problems and individualizing the intervention. However, VR-based interventions have not shown superiority compared with usual evidence-based treatments. Future VR-based interventions should focus on developing innovative approaches for complex and treatment-resistant symptoms that are difficult to address with traditional treatments. Future research should also aim to gain a better understanding of the potential factors that may mediate VR outcomes to improve treatment.
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| S-EPMC7190062 | biostudies-literature
Project description:Obesity is a highly prevalent risk factor for cardiometabolic diseases. Observational studies suggest that obesity is associated with psychiatric traits, but causal inference from such studies has several limitations. We used two-sample Mendelian randomization methods (inverse variance weighting, weighted median and MR-Egger regression) to evaluate the association of body mass index (BMI) with three psychiatric traits using data from the Genetic Investigation of Anthropometric Traits and Psychiatric Genomics consortia. Causal odds ratio estimates per 1-standard deviation increment in BMI ranged from 0.88 (95% CI: 0.62; 1.25) to 1.23 (95% CI: 0.65; 2.31) for bipolar disorder; 0.93 (0.78; 1.11) to 1.41 (0.87; 2.27) for schizophrenia; and 1.15 (95% CI: 0.92; 1.44) to 1.40 (95% CI: 1.03; 1.90) for major depressive disorder. Analyses removing potentially influential SNPs suggested that the effect estimates for depression might be underestimated. Our findings do not support the notion that higher BMI increases risk of bipolar disorder and schizophrenia. Although the point estimates for depression were consistent in all sensitivity analyses, the overall statistical evidence was weak. However, the fact that SNP-depression associations were estimated in relatively small samples reduced power to detect causal effects. This should be re-addressed when SNP-depression associations from larger studies become available.
| S-EPMC5013405 | biostudies-literature
Project description:ImportanceDelay discounting is a behavioral economic index of impulsive preferences for smaller-immediate or larger-delayed rewards that is argued to be a transdiagnostic process across health conditions. Studies suggest some psychiatric disorders are associated with differences in discounting compared with controls, but null findings have also been reported.ObjectiveTo conduct a meta-analysis of the published literature on delay discounting in people with psychiatric disorders.Data sourcesPubMed, MEDLINE, PsycInfo, Embase, and Web of Science databases were searched through December 10, 2018. The psychiatric keywords used were based on DSM-IV or DSM-5 diagnostic categories. Collected data were analyzed from December 10, 2018, through June 1, 2019.Study selectionFollowing a preregistered Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol, 2 independent raters reviewed titles, abstracts, and full-text articles. English-language articles comparing monetary delay discounting between participants with psychiatric disorders and controls were included.Data extraction and synthesisHedges g effect sizes were computed and random-effects models were used for all analyses. Heterogeneity statistics, one-study-removed analyses, and publication bias indices were also examined.Main outcomes and measuresCategorical comparisons of delay discounting between a psychiatric group and a control group.ResultsThe sample included 57 effect sizes from 43 studies across 8 diagnostic categories. Significantly steeper discounting for individuals with a psychiatric disorder compared with controls was observed for major depressive disorder (Hedges g = 0.37; P = .002; k = 7), schizophrenia (Hedges g = 0.46; P = .004; k = 12), borderline personality disorder (Hedges g = 0.60; P < .001; k = 8), bipolar disorder (Hedges g = 0.68; P < .001; k = 4), bulimia nervosa (Hedges g = 0.41; P = .001; k = 4), and binge-eating disorder (Hedges g = 0.34; P = .001; k = 7). In contrast, anorexia nervosa exhibited statistically significantly shallower discounting (Hedges g = -0.30; P < .001; k = 10). Modest evidence of publication bias was indicated by a statistically significant Egger test for schizophrenia and at the aggregate level across studies.Conclusions and relevanceResults of this study appear to provide empirical support for delay discounting as a transdiagnostic process across most of the psychiatric disorders examined; the literature search also revealed limited studies in some disorders, notably posttraumatic stress disorder, which is a priority area for research.
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Project description:ObjectiveTrauma has been proposed as a risk factor for the development of psychiatric disorders. This study aimed to determine the causal role of trauma in six common psychiatric disorders.MethodsWe obtained summary-level data for genetic variants associated with trauma and the corresponding association with psychiatric disorders from previous genome-wide association studies. Two-sample Mendelian randomization analyzes were performed to estimate the causal association between trauma and psychiatric disorders, with inverse variance weighted used as the main method.ResultsGenetically predisposed trauma was associated with an increased risk of psychiatric disorders [odds ratio (OR) =1.24, 95%, confidence interval (CI), 1.09-1.40], anxiety disorder (OR = 1.30, 95% CI, 1.10-1.52) and schizophrenia (OR = 1.48, 95% CI, 1.18-1.84). However, the associations between trauma and sleep disorder (OR = 1.17, 95% CI, 1.01-1.35), as well as depression (OR = 1.09, 95% CI, 1.02-1.16) did not reach a Bonferroni corrected significance level. Besides, no association was observed between trauma and risk of bipolar disorder (OR = 1.21, 95% CI, 0.98-1.48) and eating disorder (OR = 1.28, 95% CI, 0.88-1.86).ConclusionTrauma might be causally associated with an increased risk of some common psychiatric disorders such as anxiety disorder and schizophrenia. However, little evidence supported an association between trauma and risk of depression, bipolar disorder, sleep disorder, and eating disorder. Our findings offered novel insights into the trauma-mediated development mechanism of psychiatric disorders, and psychological intervention to patients with trauma may be an effective prevention strategy for psychological diseases.
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