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Background: The Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach is used to assess the certainty of evidence in systematic reviews and meta-analyses. Methods: We describe how the GRADE approach is used in systematic reviews and meta-analyses, including key points and examples. This overview is aimed at clinicians and researchers who are, or plan to be, involved in the development or assessment of systematic reviews with meta-analyses using GRADE. Results: We outline how the certainty of evidence is assessed, how the evidence is summarized using GRADE evidence profiles or summary of findings tables, how the results are communicated, and we discuss challenges, advantages, and disadvantages with using GRADE. Conclusions: This overview aims to provide an overview of how GRADE is used in systematic reviews and meta-analyses, and may be used by systematic review developers, methodologists, and evidence end-users.

Aim: We aimed to assess the beneficial and harmful effects of perioperative pain treatment with ketamine in patients undergoing spinal surgery. Methods: We searched Medline, Embase, and CENTRAL from inception until 15 February 2023 for randomised clinical trials comparing ketamine with placebo or no intervention in patients undergoing spinal surgery. The primary outcomes were cumulative opioid consumption at 24 h postoperatively and serious adverse events. We adhered to recommendations of the Cochrane Collaboration and performed meta-analysis, Trial Sequential Analysis (TSA) to assess the risks of random errors, risk of bias assessment to evaluate the risks of systematic errors, and used the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Results: We included a total of 28 randomised clinical trials enrolling 2110 participants providing data for our pre-defined outcomes. Twenty-three trials enrolled adult participants and 5 trials enrolled paediatric participants. Three trials were at low risk of bias. Meta-analysis and TSA of trials including adults showed that ketamine versus placebo or no intervention seemed to reduce the cumulative 24-h opioid consumption (mean difference −17.57 mg; TSA-adjusted 95% confidence interval, −24.22 to −10.92; p <.01; low certainty of evidence), and there was no evidence of a difference of ketamine versus placebo or no intervention on the risk of serious adverse events (risk ratio 2.16; 96.7% confidence interval, 0.35 to 13.17; p =.36; very low certainty of evidence). Conclusion: In adults undergoing spinal surgery, ketamine may reduce cumulative 24-h opioid consumption. Ketamine may increase the occurrence of serious adverse events, but the evidence was very uncertain.

Background and Objective: Meta-analysis and meta-regression are often highly cited and may influence practice. Unfortunately, statistical errors in meta-analyses are widespread and can lead to flawed conclusions. The purpose of this article was to review common statistical errors in meta-analyses and to document their frequency in highly cited meta-analyses from strength and conditioning research. Methods: We identified five errors in one highly cited meta-regression from strength and conditioning research: implausible outliers; overestimated effect sizes that arise from confusing standard deviation with standard error; failure to account for correlated observations; failure to account for within-study variance; and a focus on within-group rather than between-group results. We then quantified the frequency of these errors in 20 of the most highly cited meta-analyses in the field of strength and conditioning research from the past 20 years. Results: We found that 85 % of the 20 most highly cited meta-analyses in strength and conditioning research contained statistical errors. Almost half (45 %) contained at least one effect size that was mistakenly calculated using standard error rather than standard deviation. In several cases, this resulted in obviously wrong effect sizes, for example, effect sizes of 11 or 14 standard deviations. Additionally, 45 % failed to account for correlated observations despite including numerous effect sizes from the same study and often from the same group within the same study. Conclusions: Statistical errors in meta-analysis and meta-regression are common in strength and conditioning research. We highlight five errors that authors, editors, and readers should check for when preparing or critically reviewing meta-analyses.

CRUE-CSIC (Acuerdos Transformativos 2022), Recent systematic reviews of plantar warts continue to consider cryotherapy as one of the treatments of choice, but this method appears to have lower cure rates than alternative treatments. A systematic review using meta-analyses of the efficacy of cryotherapy in plantar warts treatment was performed. Systematic electronic searches were conducted. The primary endpoint was complete clearance of plantar warts. Risk-of-bias assessment was based on Cochrane Handbook recommendations. Meta-analyses used Review Manager v5.4.1 software. Cryotherapy appears to have lower cure rates than other treatments (odds ratio [OR] 0.31, 95% confidence interval [CI] 0.12–0.78) with substantial heterogeneity (I2 = 80%). A second subgroup analysis had low heterogeneity (I2 = 28.2%). Subgroup analysis showed that plantar wart cure rates were significantly lower with cryotherapy compared to the physical treatment group (OR 0.05, 95% CI 0.01–0.49) with substantial heterogeneity (I2 = 79%), and antiviral, chemotherapy, and retinoid group (OR 0.30, 95% CI 0.14–0.66) without heterogeneity (I2 = 0%). Intralesional versus spray-on cryotherapy appears to be more effective (OR 0.21, 95% CI 0.09–0.48). No difference in efficacy between two rounds of 10-s and four rounds of 5-s freeze–thaw cycles in cryotherapy was found. Evidence of the superiority of antivirals and chemotherapy over cryotherapy in the treatment of plantar warts was found. However, no evidence supports the superiority or inferiority of cryotherapy compared to other treatments., Depto. de Enfermería, Fac. de Enfermería, Fisioterapia y Podología, TRUE, pub

Worldwide, non-adherence to tuberculosis (TB) treatment is problematic. Digital adherence technologies (DATs) offer a person-centered approach to support and monitor treatment. We explored adherence over time while using DATs. We conducted a meta-analysis on anonymized longitudinal adherence data for drug-susceptible (DS) TB (n = 4515) and drug-resistant (DR) TB (n = 473) populations from 11 DAT projects. Using Tobit regression, we assessed adherence for six months of treatment across sex, age, project enrolment phase, DAT-type, health care facility (HCF), and project. We found that DATs recorded high levels of adherence throughout treatment: 80% to 71% of DS-TB patients had ≥90% adherence in month 1 and 6, respectively, and 73% to 75% for DR-TB patients. Adherence increased between month 1 and 2 (DS-TB and DR-TB populations), then decreased (DS-TB). Males displayed lower adherence and steeper decreases than females (DS-TB). DS-TB patients aged 15-34 years compared to those >50 years displayed steeper decreases. Adherence was correlated within HCFs and differed between projects. TB treatment adherence decreased over time and differed between subgroups, suggesting that over time, some patients are at risk for non-adherence. The real-time monitoring of medication adherence using DATs provides opportunities for health care workers to identify patients who need greater levels of adherence support.

Background: Spiritual interventions have proved to alleviate suffering, help the patient to prepare for end of life issues, improve quality of life, and well-being. Objective: This study aims to investigate the efficacy of religious and spiritual interventions in nursing care to promote mental, physical and spiritual health as compared to control groups not receiving such care. Methods: This is a systematic review and meta-analysis of clinical trials from SCOPUS, PUBMED, Web of Science and CINAHL databases. The searches were carried out between May and July 2020 without restrictions con cerning the date of publication. Peer-reviewed articles published in English, Portuguese or Spanish, focusing on nurses were included. This study followed the PRISMA guidelines. In addition, the CONSORT and The Cochrane Collaborations tool for assessing risk of bias were followed. Results: The search process identified 1308 publications, 18 randomized controlled trials were included for the systematic review and 9 for the meta-analysis. The meta-analyses revealed that spiritual interventions were associated with lower mental health symptoms (SMD = -6.91 [− 9.83,-3.98], p < 0.001, I2 = 99 %), greater well being (SMD = 1.26 [0.58, 1.93], p < 0.001, I2 = 94 %) and higher levels of spirituality (SMD = 0.48 [0.29, 0.67], p < 0.001, I2 = 31 %) as compared to individuals in the control group. Conclusions: Spiritual interventions seem to be effective to promote health, as seen for mental health, spirituality, well-being and physical outcomes. Nevertheless, more than half of the studies have a high risk of bias in any of the dimensions evaluated and there is an important heterogeneity among interventions and outcomes. This is particularly important to nurses and nurse managers who want to provide a holistic care to their patients.

Although there is a clear relationship between family history (FH) and the risk of gastric cancer (GC), quantification is still needed in relation to different histological types and anatomical sites, and in strata of covariates. The objective was to analyze the risk of GC according to first-degree FH in a uniquely large epidemiological consortium of GC. This investigation includes 5946 cases and 12,776 controls from 17 studies of the Stomach Cancer Pooling (StoP) Project consortium. Summary odds ratios (OR) and the corresponding 95% confidence intervals (CIs) were calculated by pooling study-specific ORs using fixed-effect model meta-analysis techniques. Stratified analyses were carried out by sex, age, tumor location and histological type, smoking habit, socioeconomic status, alcohol intake and fruit consumption. The pooled OR for GC was 1.84 (95% CI: 1.64-2.04; I2 = 6.1%, P heterogeneity = 0.383) in subjects with vs. those without first-degree relatives with GC. No significant differences were observed among subgroups of sex, age, geographic area or study period. Associations tended to be stronger for non-cardia (OR = 1.82; 95% CI: 1.59-2.05 for subjects with FH) than for cardia GC (OR = 1.38; 95% CI: 0.98-1.77), and for the intestinal (OR = 1.92; 95% CI: 1.62-2.23) than for the diffuse histotype (OR = 1.62; 95% CI: 1.28-1.96). This analysis confirms the effect of FH on the risk of GC, reporting an approximately doubled risk, and provides further quantification of the risk of GC according to the subsite and histotype. Considering these findings, accounting for the presence of FH to carry out correct prevention and diagnosis measures is of the utmost importance.

Methane (CH4) is a greenhouse gas generated during the feed fermentation processes in the rumen. However, numerous studies have been conducted to determine the capacity of plant secondary metabolites to enhance ruminal fermentation and decrease CH4 production, especially those plants rich in tannins. This review conducted a descriptive analysis and meta-analysis of the use of tannin-rich plants in tropical regions to mitigate CH4 production from livestock. The aim of this study was to analyse the effect of tannins supplementation in tropical plants on CH4 production in ruminants using a meta-analytic approach and the effect on microbial population. Sources of heterogeneity were explored using a meta-regression analysis. Final database was integrated by a total of 14 trials. The ‘meta’ package in R statistical software was used to conduct the meta-analyses. The covariates defined a priori in the current meta-regression were inclusion level, species (sheep, beef cattle, dairy cattle, and cross-bred heifers) and plant. Results showed that supplementation with tropical plants with tannin contents have the greatest effects on CH4 mitigation. A negative relationship was observed between the level of inclusion and CH4 emission (−0.09), which means that the effect of CH4 mitigation is increasing as the level of tannin inclusion is higher. Therefore, less CH4 production will be obtained when supplementing tropical plants in the diet with a high dose of tannins.

The use of gabapentinoids for perioperative pain management after total knee arthroplasty has been the subject of nine systematic reviews and meta-analyses. A critical analysis of the clinical aspects of the methodology of these publications shows major flaws which limit the interpretation for the recommended use of perioperative gabapentinoids in pain management for unilateral primary total knee arthroplasty. Consequently, readers and authors of systematic reviews and meta-analyses should critically assess the clinical aspects of the included studies.

Research is still required to establish the relationship between family history (FH) and gastric cancer (GC) in relation to different histological types and anatomical sites. The present work aimed to examine the influence of first-degree FH on the risk of GC, also according to the GC location and histological type, including 5946 cases and 12,776 controls from 17 studies of 11 countries in three continents participating in the Stomach Cancer Pooling (StoP) Project consortium. This analysis confirms the effect of FH on the risk of GC, reporting an approximately doubled risk, and provides further quantification of the risk of GC according to the subsite and histotype. Although there is a clear relationship between family history (FH) and the risk of gastric cancer (GC), quantification is still needed in relation to different histological types and anatomical sites, and in strata of covariates. The objective was to analyze the risk of GC according to first-degree FH in a uniquely large epidemiological consortium of GC. This investigation includes 5946 cases and 12,776 controls from 17 studies of the Stomach Cancer Pooling (StoP) Project consortium. Summary odds ratios (OR) and the corresponding 95% confidence intervals (CIs) were calculated by pooling study-specific ORs using fixed-effect model meta-analysis techniques. Stratified analyses were carried out by sex, age, tumor location and histological type, smoking habit, socioeconomic status, alcohol intake and fruit consumption. The pooled OR for GC was 1.84 (95% CI: 1.64-2.04; I2 = 6.1%, P heterogeneity = 0.383) in subjects with vs. those without first-degree relatives with GC. No significant differences were observed among subgroups of sex, age, geographic area or study period. Associations tended to be stronger for non-cardia (OR = 1.82; 95% CI: 1.59-2.05 for subjects with FH) than for cardia GC (OR = 1.38; 95% CI: 0.98-1.77), and for the intestinal (OR = 1.92; 95% CI: 1.62-2.23) than for the diffuse histotype (OR

Alzheimer’s (AD) and Parkinson’s diseases (PD) are the two most prevalent neurodegenerative disorders in human populations. Epidemiological studies have shown that patients suffering from either condition present a reduced overall risk of cancer than controls (i.e., inverse comorbidity), suggesting that neurodegeneration provides a protective effect against cancer. Reduced risks of several site-specific tumors, including colorectal, lung, and prostate cancers, have also been observed in AD and PD. By contrast, an increased risk of melanoma has been described in PD patients (i.e., direct comorbidity). Therefore, a fundamental question to address is whether these associations are due to shared genetic and molecular factors or are explained by other phenomena, such as flaws in epidemiological studies, exposure to shared risk factors, or the effect of medications. To this end, we first evaluated the transcriptomes of AD and PD post-mortem brain tissues derived from the hippocampus and the substantia nigra and analyzed their similarities to those of a large panel of 22 site-specific cancers, which were obtained through differential gene expression meta-analyses of array-based studies available in public repositories. Genes and pathways that were deregulated in both disorders in each analyzed pair were examined. Second, we assessed potential genetic links between AD, PD, and the selected cancers by establishing interactome-based overlaps of genes previously linked to each disorder. Then, their genetic correlations were computed using cross-trait LD score regression and GWAS summary statistics data. Finally, the potential role of medications in the reported comorbidities was assessed by comparing disease-specific differential gene expression profiles to an extensive collection of differential gene expression signatures generated by exposing cell lines to drugs indicated for AD, PD, and cancer treatment (LINCS L1000). We identified significant inverse associations of transc, The research was supported by grant number PROMETEOII/2015/021 from Generalitat Valenciana and the national grant PI17/00719 from ISCIII-FEDER., Peer Reviewed, "Article signat per 11 autors/es: Jaume Forés-Martos, Cesar Boullosa, David Rodrigo-Domínguez, Jon Sánchez-Valle, Beatriz Suay-García, Joan Climent, Antonio Falcó, Alfonso Valencia, Joan Anton Puig-Butillé, Susana Puig and Rafael Tabarés-Seisdedos", Postprint (published version)

Aim: Although biodiversity is in sharp decline around the globe, collectiing precise information on changes in overall species richness remains extremely challenging. Efficient and reliable proxy methods are therefore needed, with the diversity of higher taxa representing one such potential proxy for species-level diversity. Nonetheless, the stability of using this measure across different regions and animal taxa at the global scale has never been investigated thoroughly. Location: Global. Time period: Up to 2016. Major taxa studied: Animalia. Methods: We used a large global dataset containing published studies on diversity in the terrestrial Animalia to analyse the relationship between diversity at the family, genus and species level across different orders. Results: Family and species diversity were positively correlated, with the strongest correlations in Diptera, Hemiptera and Coleoptera. Correlations were slightly weaker in family–species than in genus–species relationships, whereas differences were stronger in observed richness than in diversity indices. Across all taxa, family–species correlations of Shannon diversity index values were independent of sample size, and they showed limited variation across biomes for the three orders containing sufficient case studies for this analysis. Based on the Shannon diversity index, the species diversity per site increased linearly with the increase in family diversity, with an average species : family diversity index ratio of 2.5, slightly lower than the ratio of 2.7 for observed species and family richness values. Main conclusions: Our study confirmed that recording family-level diversity can be a meaningful proxy for determining species-level diversity patterns in biodiversity studies, and trade-offs between identification costs and retained information content need to be considered when using higher taxon surrogacy.

In this interview, epidemiologists Dorle Hoffmann and Oliver Bayer give an insight into their experience with systematic reviews and related topics such as meta-analyses. They describe how the tasks have expanded step by step in recent years and the importance of local networking - especially with the medical library staff. Finally, the interview describes the role librarians can play in the preparation of systematic reviews and gives an insight into how the cooperation in Mainz is progressing with the development of a practical guide and joint training courses., Im vorliegenden Interview geben die Epidemiolog*innen Dorle Hoffmann und Oliver Bayer Einblick in ihre Erfahrungen mit systematischen Reviews bzw. damit verwandten Themen wie Metaanalysen. Sie beschreiben, wie sich die Aufgaben in den letzten Jahren Schritt für Schritt erweitert haben und welchen Stellenwert die Vernetzung vor Ort spielt - insbesondere mit der medizinischen Bibliothek. Zuletzt wird im Interview dargestellt, welche Rolle Bibliothekar*innen bei der Erstellung systematischer Reviews spielen können und sie geben einen Einblick, wie sich die konkrete Zusammenarbeit in Mainz mit der Entwicklung eines Praxisleitfadens und gemeinsamer Schulungsangebote gestaltet.

We performed an overview of systematic reviews and meta-analyses to summarize available data regarding the association between frailty and all-cause mortality. Medline, Embase, CINAHL, Web of Science, PsycINFO, and AMED (Allied and Complementary Medicine) databases were searched until February 2020 for meta-analyses examining the association between frailty and all-cause mortality. The AMSTAR2 checklist was used to evaluate methodological quality. Frailty exposure and the risk of all-cause mortality (hazard ratio [HR] or relative risk [RR]) were displayed in forest plots. We included 25 meta-analyses that pooled data from between 3 and 20 studies. The number of participants included in these meta-analyses ranged between <2000 and >500,000. Overall, 56%, 32%, and 12% of studies were rated as of moderate, low, and critically low quality, respectively. Frailty was associated with increased risk of all-cause mortality in 24/24 studies where the HR/RRs ranged from 1.35 [95% confidence interval (CI) 1.05–1.74] (patients with diabetes) to 7.95 [95% CI 4.88–12.96] (hospitalized patients). The median HR/RR across different meta-analyses was 1.98 (interquartile range 1.65–2.67). Pre-frailty was associated with a significantly increased risk of all-cause mortality in 7/7 studies with the HR/RR ranging from 1.09 to 3.65 (median 1.51, IQR 1.38–1.73). These data suggest that interventions to prevent frailty and pre-frailty are needed

Violence prevention programs aim to raise awareness, change attitudes, normative beliefs, motivation, and behavioral responses. Many programs have been developed and evaluated, and optimistic claims about effectiveness made. Yet comprehensive guidance on program design, implementation, and evaluation is limited. The aim of this study was to provide an up-to-date review of evidence on what works for whom. A systematic search of PsycINFO, MEDLINE, ERIC, and Sociology Collection ProQuest identified 40 reviews and meta-analyses reporting on the effectiveness of violence prevention programs among young people (age 15–30) in educational institutions, published before October 2018. These included reviews of programs designed to reduce (i) bullying, (ii) dating and relationship violence, (iii) sexual assault, and (iv) antisocial behavior. Only evaluations that reported on behavioral outcomes such as perpetration, victimization, and bystander behavior were included. The reviewed evaluations reported on programs that were mainly implemented in high-income countries in Europe and North America. The majority found small effects on violence reduction and victimization and increases in self-reported bystander behavior. Our findings expose critical gaps in evaluation research in this area and provide recommendations on how to optimize the effectiveness of future programs.

Objectives: We aimed to determine the effect of workplace violence on long-term sickness absence, and whether social support from supervisors and colleagues buffer this effect. Methods: Information on workplace violence and social support were derived from the Danish Work Environment Cohort Study in 2000, 2005, and 2010 and the Swedish Longitudinal Occupational Survey of Health in 2006 and 2008. Individual- and joint-effects on register-based long-term sickness absence were determined using logistic regression models for repeated measurements. Cohort-specific estimates were combined in random effect meta-analyses. Results: Workplace violence and low social support were independently associated with a higher risk of long-term sickness absence, and we did not find evidence of an interaction. Conclusion: Exposure to workplace violence is a risk factor for long-term sickness absence while social support is associated with a lower risk of long-term sickness absence.

(1) Introduction: With older adults, cognitive intervention programs are most often used for preventing or reversing a decline in cognitive functions, but it has been recently noted that there are insufficient high-quality research studies that report the effects of cognitive intervention on the cognitive functioning of older adults. (2) Objective: To analyze the available evidence concerning the effect of cognitive interventions for improving or maintaining the general cognitive status of older adults who present different cognitive levels. (3) Method: a review of studies published between 2010 and 2019 using the following databases: PubMed, PsycINFO, Cochrane, Google Scholar, ProQuest and Medline. (4) Results: We selected 13 systematic reviews and/or meta-analyses. The results showed that the cognitive intervention programs improved general cognitive functioning and specific cognitive functions regardless of the initial cognitive level; that cognitive decline was slowed in older persons with dementia; and there was improvement in activities of daily living. Regarding duration of the results, benefits were maintained for periods of 2 months to 5 years. (5) Conclusion: Cognitive interventions have proven effective for maintaining and/or improving cognitive functioning in older adults regardless of their initial cognitive status. Even so, there are few studies that follow up these results to see whether they are maintained in the long term and whether there is transfer to other skills of daily life. However, we were able to observe in the present review how the participants’ cognitive level varied according to sociodemographic differences, and to identify which components of cognitive programs make them more effective. Based on the results found, we highlight the importance of designing cognitive intervention programs that meet these effectiveness criteria, in order to maximize the positive effects of such programs when working with a population of older adults.

We performed an overview of systematic reviews and meta-analyses to summarize available data regarding the association between frailty and all-cause mortality. Medline, Embase, CINAHL, Web of Science, PsycINFO, and AMED (Allied and Complementary Medicine) databases were searched until February 2020 for meta-analyses examining the association between frailty and all-cause mortality. The AMSTAR2 checklist was used to evaluate methodological quality. Frailty exposure and the risk of all-cause mortality (hazard ratio [HR] or relative risk [RR]) were displayed in forest plots. We included 25 meta-analyses that pooled data from between 3 and 20 studies. The number of participants included in these meta-analyses ranged between 500,000. Overall, 56%, 32%, and 12% of studies were rated as of moderate, low, and critically low quality, respectively. Frailty was associated with increased risk of all-cause mortality in 24/24 studies where the HR/RRs ranged from 1.35 [95% confidence interval (CI) 1.05-1.74] (patients with diabetes) to 7.95 [95% CI 4.88-12.96] (hospitalized patients). The median HR/RR across different meta-analyses was 1.98 (interquartile range 1.65-2.67). Pre-frailty was associated with a significantly increased risk of all-cause mortality in 7/7 studies with the HR/RR ranging from 1.09 to 3.65 (median 1.51, IQR 1.38-1.73). These data suggest that interventions to prevent frailty and pre-frailty are needed.

Persuasive communication is designed to elicit certain thoughts and feelings in order to change the audience’s attitudes and intentions, with the ultimate goal of influencing behavior. This paper addresses the question what meta-analyses in the field of persuasion can tell us about the effects that persuasive communication can have on the audience’s behavior and on the steps leading up to that behavior. A review of these meta-analyses shows that changing intentions does not automatically lead to similar sized behavioral effects, that communicative interventions only have small to medium effects, that these effects can be obtained through ethos, pathos, and logos, and that these effects are to some extent susceptible to message design characteristics. The (small to medium) size of the effects of communicative interventions has implications for the design of research on persuasive communication as well as for the advice for practitioners.

Background:Mailed outreach promoting colorectal cancer (CRC) screening with a stool blood test kit may increase participation, but magnitude and consistency of benefit of this intervention strategy is uncertain.Aim:Conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing mailed outreach offering stool tests to usual care, clinic-based screening offers on CRC screening uptake in the United States.Methods:We performed a systematic literature search of 5 databases for RCTs of mailed outreach January 1980 through June 2017. Primary outcome was screening completion, summarized using random-effects meta-analysis as pooled differences in proportion completing screening and relative risk of achieving screening compared to control. Subgroup analyses by test type offered--fecal immunochemical test (FIT) or guaiac fecal occult blood test (gFOBT)--, presence of telephone reminders, and presence of predominant underserved/minority population within study were performed. Quality of evidence was evaluated using the GRADE framework.Results:7 RCTs which enrolled 12,501 subjects were included (n=5,703 assigned mailed outreach and n=6,798 usual care). Mailed outreach resulted in a 28% absolute (95%CI: 25–30%; I2=47%), and a 2.8-fold relative (RR 2.65, 95%CI: 2.03–3.45; I2=92%) increase in screening completion compared to usual care, with a number needed to invite of 3.6. Similar outcomes were observed across subgroups. Overall body of evidence was moderate quality.Conclusions:Mailed outreach offering a gFOBT or FIT is associated with a large and consistent increase in CRC screening completion and should be considered for more widespread implementation for improving screening rates nationwide.DOI: 10.1007/s10620-019-05587-6

In the past 50 years, the original McMaster PBL model has been implemented, experimented, revised, and modified, and is still evolving. Yet, the development of PBL is not a series of success stories, but rather a journey of experiments, failures and lessons learned. In this paper, we analyzed the meta-analyses and systematic reviews on PBL from 1992 to present as they provide a focused lens on the PBL research in the past 5 decades. We identified three major waves in the PBL research development, analyzed their impact on PBL research and practice, and offered suggestions of research gaps and future directions for the field. The first wave of PBL research (polarization: 1990-mid 2000) focused on answering the question "Does PBL work?" and the outcomes. The results were conflicting. The researchers took polarizing positions and debated over the merits of PBL throughout this wave. However, the contradictory results and the debates in fact pushed the researchers to look harder for new directions to solve the puzzle. These efforts resulted in the second wave (from outcomes to process: mid 2000-mid 2010) that focused on the question "How does PBL work?" The second wave of PBL research targeted at investigating the effects of implementation constituents, such as assessment formats or single versus curriculum wide implementations. The third wave (specialization: mid 2010 and onward) of PBL research focused on "How does PBL work in different specific contexts?" These research widened our perspectives by expanding our understanding of how PBL manifests itself in different contexts. Given the diversification of PBL and more hybrid PBL models, we suggest "Why does PBL with particular implementation characteristics for specific outcomes work or not work in the condition where it is implemented?" to be the question to answer in the next wave of PBL research.

OBJECTIVE:Review approaches assessing magnitude of differences in patient experience scores between different providers. DATA SOURCES:1990-2016 literature. STUDY DESIGN:Systematic literature review. DATA EXTRACTION METHODS:Of 812 articles mentioning "CAHPS," "patient experience," "patient satisfaction," "important(ce)," "difference," or "significance," we identified 79 possible articles, yielding 35 for data abstraction. We included 22 articles measuring magnitude of differences in patient experiences. PRINCIPAL FINDINGS:We identified three main ways of estimating magnitude of differences in patient experience scores: (1) by distribution/range of patient experience variable, (2) against external anchor, and (3) comparing a difference in patient experience on one covariate to differences in patient experience on other covariates. CONCLUSIONS:We suggest routine estimation of magnitude in patient experience research. More work is needed documenting magnitude of differences between providers to make patient experience data more interpretable and usable.

Although self-control is so important that no one from any corner of the world would dispute, it is often difficult and vulnerable. Continuous exertion is one of the most influential factors that are detrimental to self-control, which leads to a state called “ego depletion”. Before 2016, the ego depletion effect had been a hot topic for a long time. After a multi-lab replication that reported a non-significant result in 2016, however, it became highly controversial regarding whether the ego depletion effect is a true effect. In the first three articles presenting reanalyses of data from the multi-lab replication, conducting an updated meta-analysis, and implementing a pre-registered large-scale experiment, I demonstrate that the non-significant result found in the multi-lab replication may be due to the ineffectiveness of the depleting task, and there is a reliable ego depletion effect when an effective depleting task is used. Further, Iintroduce and compare several explanations of the ego depletion effect, by analyzing the pros and cons of each explanation. On the basis of this work, I propose a fine-grained new model (i.e., the CoMo model) that integrates various lines of research and is able to explain almost all counterintuitive findings in this area. The last two articles provide evidence in support of the new model but contradict other theories. The limitations and future directions are discussed.

Background: Practitioners and decision makers in the medical and insurance systems need knowledge on the relationship between work exposures and burnout. Many burnout studies – original as well as reviews - restricted their analyses to emotional exhaustion or did not report results on cynicism, personal accomplishment or global burnout. To meet this need we carried out this review and meta-analyses with the aim to provide systematically graded evidence for associations between working conditions and near-future development of burnout symptoms. Methods: A wide range of work exposure factors was screened. Inclusion criteria were: 1) Study performed in Europe, North America, Australia and New Zealand 1990–2013. 2) Prospective or comparable case control design. 3) Assessments of exposure (work) and outcome at baseline and at least once again during follow up 1–5 years later. Twenty-five articles met the predefined relevance and quality criteria. The GRADE-system with its 4-grade evidence scale was used. Results: Most of the 25 studies focused emotional exhaustion, fewer cynicism and still fewer personal accomplishment. Moderately strong evidence (grade 3) was concluded for the association between job control and reduced emotional exhaustion and between low workplace support and increased emotional exhaustion. Limited evidence (grade 2) was found for the associations between workplace justice, demands, high work load, low reward, low supervisor support, low co-worker support, job insecurity and change in emotional exhaustion. Cynicism was associated with most of these work factors. Reduced personal accomplishment was only associated with low reward. There were few prospective studies with sufficient quality on adverse chemical, biological and physical factors and burnout. Conclusion: While high levels of job support and workplace justice were protective for emotional exhaustion, high demands, low job control, high work load, low reward and job insecurity increased the ri

Background Despite a large body of research on planning performance in adult schizophrenia patients, results of individual studies are equivocal, suggesting either no, moderate or severe planning deficits. This meta-analysis therefore aimed to quantify planning deficits in schizophrenia and to examine potential sources of the heterogeneity seen in the literature.Method The meta-analysis comprised outcomes of planning accuracy of 1377 schizophrenia patients and 1477 healthy controls from 31 different studies which assessed planning performance using tower tasks such as the Tower of London, the Tower of Hanoi and the Stockings of Cambridge. A meta-regression analysis was applied to assess the influence of potential moderator variables (i.e. sociodemographic and clinical variables as well as task difficulty).Results The findings indeed demonstrated a planning deficit in schizophrenia patients (mean effect size: ; 95% confidence interval 0.56-0.78) that was moderated by task difficulty in terms of the minimum number of moves required for a solution. The results did not reveal any significant relationship between the extent of planning deficits and sociodemographic or clinical variables.Conclusions The current results provide first meta-analytic evidence for the commonly assumed impairments of planning performance in schizophrenia. Deficits are more likely to become manifest in problem items with higher demands on planning ahead, which may at least partly explain the heterogeneity of previous findings. As only a small fraction of studies reported coherent information on sample characteristics, future meta-analyses would benefit from more systematic reports on those variables.

Pre-diagnostic serum/plasma concentrations of B-cell activation markers have been associated with future risk of B-cell lymphomas (BCL) in HIV-infected patients and in the general population. Current evidence for the general population is however limited and relies on relatively small numbers of observations, especially for specific histologies. We carried out a nested case-control study, including 218 BCL and 218 matched controls, within two prospective cohorts, to investigate the association between plasma levels of soluble (s)CD27 and sCD30 and future risk of BCL, and main histologic subtypes separately. To expand the evidence further, we performed meta-analyses of the published data on these associations from prospective studies among the general population. Our study revealed a significant relationship between sCD30 concentration and BCL risk (OR=0.86, 1.53, 1.76, for the 2(nd) -4(th) quartiles respectively, P-trend=0.01). Similar increased risks were observed for diffuse large B-cell lymphoma and follicular lymphoma. Analyses of sCD27 blood concentrations did not show significant associations with BCL, (OR=0.90, 1.26, 1.65 for the 2(nd) -4(th) quartiles, respectively, P-trend=0.17), but significant associations were observed for chronic lymphocytic leukaemia and for the group of ‘other BCL’ subtypes. Our findings involving sCD30 were confirmed within our meta-analyses of five prospective cohorts, while results were more heterogeneous for sCD27 with the exception of CLL which was found consistently in all studies. Data to date suggest that chronic B-cell stimulation might be an important mechanism involved in B-cell lymphomagenesis both in HIV-infected and in the general population. This article is protected by copyright. All rights reserved.

Human embryonic stem cell (hESC) neural differentiation models have tremendous potential for evaluating environmental compounds in terms of their ability to induce neurodevelopmental toxicity. Genomic based-approaches are being applied to identify changes underlying normal human development (in vitro and in vivo) and the effects of environmental exposures. Here, we investigated whether mechanisms that are shared between hESC neural differentiation model systems and human embryos are candidate biomarkers of developmental toxicities for neurogenesis. We conducted a meta-analysis of transcriptomic datasets with the goal of identifying differentially expressed genes that were common to the hESC-model and human embryos. The overlapping NeuroDevelopmental Biomarker (NDB) gene set contained 304 genes which were enriched for their roles in neurogenesis. These genes were investigated for their utility as candidate biomarkers in the context of toxicogenomic studies focused on the effects of retinoic acid, valproic acid, or carbamazepine in hESC models of neurodifferentiation. The results revealed genes, including 13 common targets of the 3 compounds, that were candidate biomarkers of neurotoxicity in hESC-based studies of environmental toxicants.

Managing ecological systems, which operate over large spatial scales, is inherently difficult and often requires sourcing data from different countries and organizations. The assumption might be made that data collected using similar methodologies are comparable, but this is rarely tested. Here, benthic video data recorded using different towed underwater video systems (TUVSs) were experimentally compared. Three technically different TUVSs were compared on different seabed types (rocky, mixed ground and sandy) in Kingmere Marine Conservation Zone, off the south coast of England. For each TUVS, species metrics (forward facing camera), seabed impact (backward facing camera) and operational performance (strengths and limitations of equipment and video footage) were compared with the aim of providing recommendations on their future use and comparability of data between different systems. Statistically significant differences between species richness, density, cover and assemblage composition were detected amongst devices and were believed to be mostly due to their optical specifications. As a result of their high image definition and large field of vision both the benthic contacting heavy and benthic tending TUVS provided good quality footage and ecological measurements. However, the heaviest TUVS proved difficult to operate on irregular ground and was found to cause the most impact to the seabed. The lightest TUVS (benthic contacting light) struggled to maintain contact with the seabed. The benthic tending TUVS was able to fly over variable seabed relief and was comparably the least destructive. Results from this study highlight that particular care should be given to sled and optic specifications when developing a medium- or long-term marine protected area monitoring programme. Furthermore, when using data gathered from multiple sources to test ecological questions, different equipment specifications may confound observed ecological differences. A benthic tending TUVS

A meta-analysis assessing the magnitude of sleep changes from baseline in placebo-treated (psychological and pharmacological placebo) and untreated groups issued from independent trials was conducted. Comparisons were then performed to assess if the magnitude of sleep changes in the placebo control groups were significantly different than those of the untreated group. Medline, PsychInfo and Current Contents databases (1990–2004) were searched for primary insomnia treatment studies using a randomized controlled parallel-group design. Effect sizes were computed for each end-point variable based on subjective (patient-reported) and polysomnographic measures. Thirty-four studies (n = 1392 subjects) met inclusion criteria; twenty-three used a pharmacological placebo (n = 1163), four used a psychological placebo (n = 81), and seven used a waitlist condition (n = 148). Between-group comparisons were performed using a random effects model analysis. Significant pre–post changes were observed in the pharmacological placebo condition on several sleep parameters, both on objectively and subjectively measured outcomes [objective and subjective sleep onset latency (SOL) and total sleep time (TST) and subjective wake after sleep onset]. Although a tendency was observed for objective SOL, only the changes on subjective SOL and TST in the pharmacological placebo condition were significantly different from the corresponding changes in the untreated group. No differences were significant for the psychological placebo groups. Although the present findings suggest that sleep may significantly change in response to a pharmacological placebo, conclusions remain tentative because of possible confounds that may arise when comparing groups issued from different trials. Further research directly comparing placebo groups and untreated groups from the same randomized trials remains necessary.

Transmembrane protease, serine 6 (TMPRSS6), is likely to be involved in iron metabolism through its pleiotropic effect on hepcidin concentrations. Recently, genome-wide association studies have identified common variants in the TMPRSS6 gene to be linked to anaemia and low iron status. To get a more precise evaluation of identified TMPRSS6 single nucleotide polymorphism associations with iron status in cohorts of differing continental ancestry, we conducted a systematic review with meta-analyses. We searched the literature using HuGE Navigator, Pubmed and Scopus databases for primarily genome-wide association studies using TMPRSS6 as a free term. Fixed-effects meta-analysis was used to obtain summary estimates of associations. Eleven studies comprised Caucasian populations, four included an Asian population and one study included an African-American population. Differences in minor allele frequencies of 8 TMPRSS6 SNPs (rs855791, rs4820268, rs2111833, rs1421312, rs228921, rs228918, rs228919 and rs575620) across ethnic groups were observed, with the MAF of rs855791 significantly higher in Asian populations than in Caucasians (0.55 vs 0.42, P < 0.0001). In the meta-analysis, the A allele of rs855791 was associated with lower Hb and ferritin concentrations in all populations. This allele was also associated with increased serum transferrin receptor and transferrin concentrations. We observed similar associations for the G allele in rs4820268. Clear disparities in associations were found for the African-American population, although not statistically significant. Associations between TMPRSS6 SNPs and anaemia are consistent across Caucasian and Asian populations. This study highlights the need to conduct studies in African populations where iron deficiency is of utmost public health significance.

Autoimmune thyroid diseases (AITD) are common, affecting 2-5% of the general population. Individuals with positive thyroid peroxidase antibodies (TPOAbs) have an increased risk of autoimmune hypothyroidism (Hashimoto's thyroiditis), as well as autoimmune hyperthyroidism (Graves' disease). As the possible causative genes of TPOAbs and AITD remain largely unknown, we performed GWAS meta-analyses in 18,297 individuals for TPOAb-positivity (1769 TPOAb-positives and 16,528 TPOAb-negatives) and in 12,353 individuals for TPOAb serum levels, with replication in 8,990 individuals. Significant associations (P<5×10−8) were detected at TPO-rs11675434, ATXN2-rs653178, and BACH2-rs10944479 for TPOAb-positivity, and at TPO-rs11675434, MAGI3-rs1230666, and KALRN-rs2010099 for TPOAb levels. Individual and combined effects (genetic risk scores) of these variants on (subclinical) hypo- and hyperthyroidism, goiter and thyroid cancer were studied. Individuals with a high genetic risk score had, besides an increased risk of TPOAb-positivity (OR: 2.18, 95% CI 1.68–2.81, P = 8.1×10−8), a higher risk of increased thyroid-stimulating hormone levels (OR: 1.51, 95% CI 1.26–1.82, P = 2.9×10−6), as well as a decreased risk of goiter (OR: 0.77, 95% CI 0.66–0.89, P = 6.5×10−4).The MAGI3 and BACH2 variants were associated with an increased risk of hyperthyroidism, which was replicated in an independent cohort of patients with Graves' disease (OR: 1.37, 95% CI 1.22–1.54, P = 1.2×10−7 and OR: 1.25, 95% CI 1.12–1.39, P = 6.2×10−5). The MAGI3 variant was also associated with an increased risk of hypothyroidism (OR: 1.57, 95% CI 1.18–2.10, P = 1.9×10−3). This first GWAS meta-analysis for TPOAbs identified five newly associated loci, three of which were also associated with clinical thyroid disease. With these markers we identified a large subgroup in the general population with a substantially increased risk of TPOAbs. The results provide insight into why individuals with thyroid autoimmunity do or do n

There is no clear candidate tool for assessing the methodological quality of ex post facto studies in systematic reviews and meta-analyses yet. Our purpose is to thoroughly analyze the psychometric properties of the three most comprehensive assessment tools of this kind published up to 2010. We selected these tools from a previous systematic review, and we applied each one to assess the quality of 10 prospective studies, 10 retrospective studies with quasi-control group, and 10 cross-sectional studies. Inter-rater reliability for the first two aforementioned research designs is moderate only for one of the selected tools, and moderate to high for all of them for cross-sectional studies. Agreement between tools is low in general, although the inferred aspects show that the tools have a relative good conceptual overlapping in most of the domains. According to these results we recommend two tools for assessing cross-sectional studies, but we consider that the tools applicable to prospective studies or retrospective studies with quasi-control group require further testing. The 30 concrete aspects that we have inferred from the items of the three analyzed tools can be used as starting point to develop a new tool of this kind

Background Diabetes and increased age are known risk factors for physical disability. With the increasing prevalence of diabetes within our aging population, the future burden of disability is expected to increase. To date, there has not been a pooled estimate of the risk for disability associated with diabetes or its precursor states, impaired glucose tolerance and impaired fasting glucose. We aim to conduct a systematic review and meta-analysis of the association between prediabetes and diabetes with disability, and quantify the risk of association. Methods/design We will search for relevant studies in Medline via Pubmed, Embase, Cochrane library and Cumulative Index to Nursing and Allied Health Literature (CINAHL), as well as scan reference lists from relevant reviews and publications included in our review. We will review all publications that include studies on human adults (18 years and older) where information is included on diabetes status and at least one measure of disability (Activities of Daily Living (ADL), Instrumental ADL (IADL) or functional/mobility limitation), and where a risk association is available for the relationship between diabetes and/or prediabetes with disability, with reference to those without diabetes. We will further conduct a meta-analysis to pool estimates of the risk of disability associated with prediabetes and diabetes. Sensitivity analysis will be conducted to assess for publication bias and study quality.Findings from this systematic review and meta-analysis will be widely disseminated through discussions with stake-holders, publication in a peer-reviewed journal and conference presentation.

The key objective of this thesis is to provide empirical evidence to demonstrate or disprove claims that findings from a major systematic review of the outcomes of routine episiotomy published in JAMA in 2005 (Hartmann et al.) have led to further declines in the practice of episiotomy. In addition, the thesis will study the trend in episiotomy rates for the civilian population. The primary research questions addressed in this thesis are as follows: (1) Has Hartmann et al's study had any effect on episiotomy rates and practice variations?; and (2) How does the study's effect on episiotomy rates vary across hospital types and patients? The study used data from the Healthcare Cost and Utilization Project: State Inpatient Databases (HCUP SID) and American Hospital Association (AHA) annual surveys. The sample consisted of 648,141 patients from 897 hospitals in eight states between 2003 and 2008. Both fixed and random effects models were specified to estimate the effects of the JAMA publication on episiotomy rates. In addition, the study analyzed variations in practice patterns to find out whether the JAMA publication has had a desirable impact on clinical practices. The results show that the declining episiotomy rate continued to decline after the JAMA publication, but only marginally. The analysis of variations in practice patterns shows that variations in episiotomy rates remain substantial. More effective strategies should be formulated to reach out to different audiences to bridge the gap between research evidence and clinical practice with regard to episiotomy.

Low back pain (LBP) is a common and disabling disorder in western society. The management of LBP comprises a range of different intervention strategies including surgery, drug therapy, and non-medical interventions. The objective of the present study is to determine the effectiveness of physical and rehabilitation interventions (i.e. exercise therapy, back school, transcutaneous electrical nerve stimulation (TENS), low level laser therapy, education, massage, behavioural treatment, traction, multidisciplinary treatment, lumbar supports, and heat/cold therapy) for chronic LB

Meta-analyses and Individual Patient Data (IPD) meta-analyses of genetic association studies are a powerful tool to summarize the scientific evidences, however their application present considerable potential and several pitfalls. We reviewed systematically all published meta-analyses and IPD meta-analyses of genetic association studies in the field of cancer research, searching for relevant studies on the Medline, Embase, and HuGE Reviews Archive databases until January 2009. The association between selected predictors of methodological quality and the year of publication was also evaluated. 144 meta-analyses involving 299 gene-disease associations, and 25 IPD meta-analyses on 83 gene-disease were included. Overall quality of the reports showed a substantial improvement over time, as authors have become more inclusive of primary papers published in all languages since 2005 (P-value = 0.087), as well as statistical heterogeneity and publication bias were evaluated more systematically. Only 35.4% of the meta-analyses, however, adopted a comprehensive bibliographic search strategy to identify the primary reports, 63.9% did not specify the language of the included studies, 39.8% did not test for Hardy-Weinberg Equilibrium (HWE), while 62.2 and 75.9% of the meta-analyses and IPD meta-analyses, respectively, did not declare the scientific rationale for the genetic model chosen. Additionally, the HWE assessment showed a substantial decreasing trend over time (P-value = 0.031) while publication bias was more often evaluated when statistical heterogeneity was actually present (P-value = 0.007). Although we showed a general methodological improvement over time, guidelines on conducting and reporting meta-analyses of genetic association studies are needed to enhance their methodological quality

A meta-analysis was performed to examine the generalizability of the predictive validity of the Air Force Officer Qualifying Test (AFOQT) operational composites against technical training performance for 14 non-rated Air Force Specialties. AFOQT data were from Form Q and were used to compute composites based on Form S specifications. All five operational composites (Verbal, Quantitative, Academic Aptitude, Pilot, and Navigator/Technical) were included in the analyses. Analyses began by examining the observed correlation between the AFOQT composites and technical training final grade for each officer training course. The meta-analysis of the observed correlations was corrected only for sampling error. The observed correlations then were corrected for range restriction using the multivariate method and the meta-analysis was repeated. The range-restriction corrected correlations were then corrected for unreliability of the test scores and training criterion and the meta-analysis was repeated. This third set of correlations provides a theoretical estimate of the predictiveness of the composites when perfectly reliable measures are available. Ninety percent of the observed correlations between the AFOQT composites and average officer technical training grades were statistically significant at or beyond the .05 level, thus supporting its value in selecting non-rated officers. Results of the meta-analyses of the observed correlations indicated that the predictive validity for 4 of the 5 AFOQT composites (Verbal, Academic Aptitude, Pilot, and Navigator/Technical) was not the same across the non-rated officer training specialties. Validity generalization was observed only for the Quantitative composite. After correction for range restriction, 4 of the 5 composites demonstrated validity generalization across the training specialties. This means that the true validity of the AFOQT composites (except Verbal) was consistent across the officer training specialties.

Objectives. To compare perinatal and maternal outcomes between elective induction of labor versus expectant management of pregnancies at 41 weeks and beyond. Design. Systematic review and meta-analysis. Methods. We searched PubMed, CINAHL, Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effectiveness (DARE) and PsycINFO (1980 to November, 2007). Inclusion criteria were systematic reviews and randomized controlled trials comparing elective induction of labor versus expectant management of pregnancies at 41 weeks and beyond. Three or more reviewers independently read and evaluated all selected studies. Data were extracted and analyzed using Review Manager Software. Main outcome measures. Perinatal mortality. Results. Thirteen trials fulfilled the inclusion criteria for the meta-analysis. Elective induction of labor was not associated with lower risk of perinatal mortality compared to expectant management (relative risks (RR): 0.33; 95% confidence intervals (CI): 0.10-1.09). Elective induction was associated with a significantly lower rate of meconium aspiration syndrome (RR: 0.43; 95% CI: 0.23-0.79). More women randomized to expectant management were delivered by cesarean section (RR: 0.87; 95% CI: 0.80-0.96). Conclusions. The meta-analysis illustrated a problem with rare outcomes such as perinatal mortality. No individual study with adequate sample size has been published, nor would a meta-analysis based on the current literature be sufficient. The optimal management of pregnancies at 41 weeks and beyond is thus unknown.

Authors report the results of four meta-analyses of studies that examined the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and head and neck cancer (nine studies, 2076 cases and 4834 controls for C677T; four studies, 1439 cases and 3941 controls for A1298C), and lung cancer (ten studies, 5274 cases and 7435 controls for C677T; seven studies, 5098 cases and 6243 controls for A1298C). The summary odds ratio (OR) of head and neck cancer was 0.92 (95% CI: 0.76-1.11) for MTHFR 677 TT and 0.68 (95% CI: 0.37-1.26) for MTHFR 1298 CC. The OR of lung cancer was 1.22 [95% confidence interval (CI): 0.95-1.55] for MTHFR 677 TT and 1.07 (95% CI: 0.83-1.38) for MTHFR 1298 CC. Results from the meta-analysis of three studies on C677T stratified according to dietary folate intake showed an increased risk for individuals with low folate intake (OR = 1.37, 95% CI: 0.92-2.06 for head and neck and OR = 1.28, 95% CI: 0.97-1.68 for lung) versus high folate intake (OR = 0.85, 95% CI: 0.63-1.16 for head and neck, and OR = 0.94, 95% CI: 0.79-1.12 for lung). Despite the lack of formal statistical significance, these findings are consistent with the hypothesis that folate play a role in lung and head/neck carcinogenesis, and show the need to incorporate data on folate intake when interpreting results of MTHFR polymorphisms in relation to cancer risk

A meta-analysis assessing the magnitude of sleep changes from baseline in placebotreated (psychological and pharmacological placebo) and untreated groups issued from independent trials was conducted. Comparisons were then performed to assess if the magnitude of sleep changes in the placebo control groups were significantly different than those of the untreated group. Medline, PsychInfo and Current Contents databases (1990–2004) were searched for primary insomnia treatment studies using a randomized controlled parallel-group design. Effect sizes were computed for each end-point variable based on subjective (patient-reported) and polysomnographic measures. Thirty-four studies (n ¼ 1392 subjects) met inclusion criteria; twenty-three used a pharmacological placebo (n ¼ 1163), four used a psychological placebo (n ¼ 81), and seven used a waitlist condition (n ¼ 148). Between-group comparisons were performed using a random effects model analysis. Significant pre–post changes were observed in the pharmacological placebo condition on several sleep parameters, both on objectively and subjectively measured outcomes [objective and subjective sleep onset latency (SOL) and total sleep time (TST) and subjective wake after sleep onset]. Although a tendency was observed for objective SOL, only the changes on subjective SOL and TST in the pharmacological placebo condition were significantly different from the corresponding changes in the untreated group. No differences were significant for the psychological placebo groups. Although the present findings suggest that sleep may significantly change in response to a pharmacological placebo, conclusions remain tentative because of possible confounds that may arise when comparing groups issued from different trials. Further research directly comparing placebo groups and untreated groups from the same randomized trials remains necessary.