Meta-Analysis With Complex Research Designs: Dealing With Dependence From Multiple Measures and Multiple Group Comparisons

Summarizing attributable factors and evaluating risk of bias of Mendelian randomization studies for Alzheimer's dementia and cognitive status: a systematic review and meta-analysis

BACKGROUND

No effective treatment is available to delay or reverse the onset and progression of Alzheimer's dementia (AD). Mild cognitive impairment, a clinical state between normal aging and AD, may offer the proper window for AD intervention and treatment. This systematic review aimed to summarize evidence from Mendelian randomization (MR) studies exploring factors attributable to AD and related cognitive status and to assess its credibility.

METHODS

We searched PubMed, Embase, MEDLINE, and the Cochrane Library to identify MR studies investigating the associations between any factor and AD and related cognitive status. The risk of bias in MR studies was evaluated using nine signaling questions tailored to identify potential biases based on the STROBE-MR guidelines.

RESULTS

A total of 125 eligible publications were examined, including 106 AD-related MR studies reporting 674 records and 28 cognition-related MR studies reporting 141 records. We identified 185 unique causal risk factors for AD and 49 for cognitive status. More than half of the MR studies reporting AD or cognitive status outcomes exhibited poor methodological quality, with a high risk of bias observed in 59% of the AD-related studies and 64% of the cognitive-related studies.

CONCLUSIONS

This systematic review summarized modifiable factors and omics signatures, providing a database of MR studies on AD and related cognitive status. The evaluation of bias risk in MR studies serves to raise awareness and improve overall quality. A critical appraisal checklist for assessing the risk of bias may pave the way for the development of a standardized tool.

SYSTEMATIC REVIEW REGISTRATION

The review protocol was registered with the Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD42023213990.

Acute immune system activation exerts time-dependent effects on inhibitory control: Results of both a randomized controlled experiment of influenza vaccination and a systematic review and meta-analysis - ISPNE 2024 Dirk Hellhammer Award

Although coming down with an illness or receiving a vaccine are both common experiences, the influence of such acute immune system activations on cognitive processes, such as inhibitory control, has received relatively little attention. We addressed that issue by assessing the effects of acute immune system activation on inhibitory control in a randomized controlled experiment, and by conducting a meta-analysis of similar studies in humans. In our experiment, we found-somewhat surprisingly-that influenza vaccination improved performance on both of our inhibitory control outcomes (i.e., stop-signal reaction times and flanker interference effects). At the meta-analytic level, we found that at a short delay (1.5-4 hours post-injection) between immune activation and inhibitory control assessment, such activation impaired multiple forms of inhibitory control, whereas after a longer delay (e.g., > 18 hours post-injection), such activation improved inhibitory control-consistent with our experiment. Moreover, proinflammatory cytokine activity predicted poorer interference control but better response inhibition, even with a long delay between injection and testing. Together, these results highlight nuanced, time-dependent, and-perhaps-multiple-mechanism-driven effects of acute immune system activity on inhibitory control.

Investigating the effects of cortico-cortical paired associative stimulation in the human brain: A systematic review and meta-analysis

Recent decades have witnessed a rapid development of novel neuromodulation techniques that allow direct manipulation of cortical pathways in the human brain. These techniques, known as cortico-cortical paired stimulation (ccPAS), apply magnetic stimulation over two cortical regions altering interregional connectivity. This review evaluates ccPAS's effectiveness to induce plastic changes in cortical pathways in the healthy brain. A systematic database search identified 41 studies investigating the effect of ccPAS on neurophysiological or behavioural measures, and a subsequent multilevel meta-analysis focused on the standardized mean differences to assess ccPAS's efficacy. Most studies report significant neurophysiological and behavioural changes from ccPAS interventions across several brain networks, consistently showing medium effect sizes. Moderator analyses revealed limited influence of experimental manipulations on effect sizes. The multivariate approach and lack of small-study bias suggest reliable effect estimates. ccPAS is a promising tool to manipulate neuroplasticity in cortical pathways, showing reliable effects on brain cortical networks. Important areas for further research on the influence of experimental procedures and the potential of ccPAS for clinical interventions are highlighted.

Evaluating the treatment utility of the Cognitive Assessment System: A meta-analysis of reading and mathematics outcomes

There has been a long search for cognitive assessments that reveal aptitudes thought to be useful for treatment planning. In this regard, since the 1990s, there has been some enthusiasm for the Cognitive Assessment System (CAS) and its potential promise for informing treatment due to its alignment of theory, assessment instrument, and suite of interventions. The purpose of this meta-analytic review was to synthesize research pertinent to the treatment utility of the CAS according to a taxonomy of treatment utility. A total of 252 articles were produced by an electronic search and eligibility screening yielded 16 articles meeting criteria for consideration. Most studies described in these articles utilized obtained difference designs, focused on the Planning composite scores from the CAS, and addressed math interventions. Only seven studies with publication dates from 1995 to 2010 yielded sufficient information to be included in the meta-analysis. A random effects model was employed to determine the overall treatment utility effect across 114 participants apportioned to 14 groups and comprising eight comparisons. Results yielded an overall moderate effect size (0.64, 95% CI [0.24, 1.03], p = .002), but it was associated with significant imprecision (due to a low number of viable studies and small sample sizes across most studies) that prohibits reliable conclusions from being drawn. Assessment of between-study heterogeneity and moderator analysis was not possible. Considering these findings, additional research is needed to support the treatment utility of the CAS-even after more than 27 years of study. Furthermore, there are no published studies regarding the treatment utility of the second edition of the CAS, which was published in 2014. These results suggest that there is insufficient empirical grounding to enable practitioners to use this instrument to develop effective treatments for reading, mathematics, or writing. More direct interventions designed to enhance academic skill development should be employed.

Efficacy of lifestyle interventions to treat pediatric obesity: A systematic review and multivariate meta-analysis of randomized controlled trials

The aim of this study was to provide a quantitative synthesis of the effects of randomized controlled pediatric lifestyle interventions in treating obesity among 11-17-year-old children. We conducted a systematic review and meta-analysis on the randomized controlled trials, consisting of actual exercise training and nutrition education, published between January 2000 and August 2022. The initial search yielded 2598 articles, with eight articles meeting the inclusion criteria. The articles were analyzed using a multivariate random effects model. The primary outcome variables were body mass index (BMI), standardized BMI (BMIz), and waist circumference (WC). Our analyses showed that lifestyle interventions were efficacious in improving BMI (-1.77 kg/m2, 95% CI [-2.70, -0.83], p < 0.001), BMIz (-0.30, 95% CI [-0.45, -0.16], p < 0.001), and WC (-3.32 cm, 95% CI [-5.35, -1.29], p < 0.001) in children with overweight and obesity. In addition, moderation analyses suggested that the efficacy of the lifestyle interventions correlated positively with participants' weight status and was enhanced when an intervention was boosted with a longer intervention duration and higher frequency. In conclusion, the current evidence suggests that lifestyle interventions are efficacious in treating children with obesity. The available evidence further indicates that duration, frequency, along weight status, were moderating the effectiveness of these lifestyle interventions.

Anxiety, history of childhood adversity, and experiencing chronic pain in adulthood: A systematic literature review and meta-analysis

BACKGROUND

When considering factors that may impact chronic pain experiences in adulthood, adverse childhood experiences (ACEs) and anxiety should be considered. The literature on the associations between these 3 variables remains unclear.

OBJECTIVE

To summarize the existing literature on the relationship between ACEs and anxiety on chronic pain experience in adults, and examine the association between ACEs and anxiety.

METHODS

A systematic literature review (SLR) and meta-analysis was used to examine adults (≥18) with a reported history of ACEs, self-reported and/or diagnosed anxiety, and chronic pain. The SLR included quality appraisal according to the Joanna Briggs Institute tool.

RESULTS

The narrative summary indicated a significant association between ACEs, anxiety, and chronic pain experiences in adults. Of 52 selected studies, 79% reported a moderate-strong association. For ACE prevalence, the majority reported experiencing sexual abuse (50% [SD 16.01]), followed by physical abuse (46% [SD 20.7]). Other ACEs included emotional abuse (33% [SD 17.17]), emotional neglect (25% [SD 21.02]), and physical neglect (23% [SD 22.44]). Meta-analyses showed moderate associations between anxiety and chronic pain (r = 0.30; 95% CI = [0.14, 0.45], p < 0.01) and between ACEs and anxiety (r = 0.26; 95% CI = [0.15, 0.36], p < 0.01), and that participants who experienced ACEs are around twice as likely to present chronic pain during adulthood (OR = 1.99; 95% CI = [1.53, 2.60], p < 0.01).

CONCLUSION

The results of the SLR and meta-analysis indicated that ACEs and anxiety influence chronic pain experience in adults. Given the relationship between ACEs and anxiety, there would be value in exploring this as a potential mediator in future studies.

SIGNIFICANCE

There was an unmet need to summarize the existing literature on the relationship between ACEs and anxiety on chronic pain experience in adults and the association between ACEs and anxiety. The results of this systematic review and meta-analysis indicated that both ACEs and anxiety influenced chronic pain experience in adults and helped to inform the diverse literature on these potential relationships to date.

A systematic review and multivariate meta-analysis of the physical and mental health benefits of touch interventions

Receiving touch is of critical importance, as many studies have shown that touch promotes mental and physical well-being. We conducted a pre-registered (PROSPERO: CRD42022304281) systematic review and multilevel meta-analysis encompassing 137 studies in the meta-analysis and 75 additional studies in the systematic review (n = 12,966 individuals, search via Google Scholar, PubMed and Web of Science until 1 October 2022) to identify critical factors moderating touch intervention efficacy. Included studies always featured a touch versus no touch control intervention with diverse health outcomes as dependent variables. Risk of bias was assessed via small study, randomization, sequencing, performance and attrition bias. Touch interventions were especially effective in regulating cortisol levels (Hedges' g = 0.78, 95% confidence interval (CI) 0.24 to 1.31) and increasing weight (0.65, 95% CI 0.37 to 0.94) in newborns as well as in reducing pain (0.69, 95% CI 0.48 to 0.89), feelings of depression (0.59, 95% CI 0.40 to 0.78) and state (0.64, 95% CI 0.44 to 0.84) or trait anxiety (0.59, 95% CI 0.40 to 0.77) for adults. Comparing touch interventions involving objects or robots resulted in similar physical (0.56, 95% CI 0.24 to 0.88 versus 0.51, 95% CI 0.38 to 0.64) but lower mental health benefits (0.34, 95% CI 0.19 to 0.49 versus 0.58, 95% CI 0.43 to 0.73). Adult clinical cohorts profited more strongly in mental health domains compared with healthy individuals (0.63, 95% CI 0.46 to 0.80 versus 0.37, 95% CI 0.20 to 0.55). We found no difference in health benefits in adults when comparing touch applied by a familiar person or a health care professional (0.51, 95% CI 0.29 to 0.73 versus 0.50, 95% CI 0.38 to 0.61), but parental touch was more beneficial in newborns (0.69, 95% CI 0.50 to 0.88 versus 0.39, 95% CI 0.18 to 0.61). Small but significant small study bias and the impossibility to blind experimental conditions need to be considered. Leveraging factors that influence touch intervention efficacy will help maximize the benefits of future interventions and focus research in this field.

Research Review: Child emotion regulation mediates the association between family factors and internalizing symptoms in children and adolescents - a meta-analysis

BACKGROUND

Parental influence on children's internalizing symptoms has been well established; however, little is known about the underlying mechanisms. One possible mechanism is child emotion regulation given evidence (a) of its associations with internalizing symptoms and (b) that the development of emotion regulation during childhood and adolescence is influenced by aspects of the family environment. This meta-analysis aimed to systematically investigate the mediating role of child emotion regulation in the relationship between various family factors and internalizing symptoms in children and adolescents.

METHODS

We searched Medline, Embase, PsychInfo, and Web of Science for English articles up until November 2022. We included studies that examined child emotion regulation as a mediator between a family factor and child/adolescent internalizing symptoms. Random-effects models were used to calculate pooled indirect effects and total effects for nine family factors. Heterogeneity and mediation ratio were also calculated.

RESULTS

Of 49 studies with 24,524 participants in this meta-analysis, family factors for which emotion regulation mediated the association with child/adolescent internalizing symptoms included: unsupportive emotion socialization, psychological control, secure attachment, aversiveness, family conflict, parent emotion regulation and parent psychopathology, but not supportive emotion socialization and behavioral control.

CONCLUSIONS

Various family factors impact children's emotion regulation development, and in turn, contribute to the risk of internalizing symptoms in young people. Findings from this study highlight the need for interventions targeting modifiable parenting behaviors to promote healthy emotion regulation and better mental health in children and adolescents.

Do interventions for mood improve inflammatory biomarkers in inflammatory bowel disease?: a systematic review and meta-analysis

BACKGROUND

Psychoneuroimmunological mechanisms and the gut-brain axis appear relevant to disease activity and progression in Inflammatory Bowel Disease (IBD). A recent review showed no effect of psychological therapies on self-reported disease activity in IBD. This meta-analysis aims to establish whether interventions targeting mood outcomes (e.g., depression, anxiety and stress) impact inflammation levels in IBD and possible moderators of these effects.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. We searched five electronic databases and included randomised controlled trials where interventions targeted mood and assessed inflammatory outcomes pre- and post-intervention in adults with IBD. Independent reviewers screened studies, extracted data, and assessed methodological quality. Data were pooled to estimate standardised mean differences (SMDs) with 95% Confidence Intervals (CIs). A random-effects robust variance estimation accounted for studies measuring multiple biomarkers. Intervention type, mood as a primary or secondary outcome, effect on mood outcomes and IBD subtype were investigated as treatment effect moderators. Where there were sufficient biomarkers, individual meta-analyses were run (Pre-registration PROSPERO: CRD42023389401).

FINDINGS

28 RCTs involving 1789 participants met inclusion criteria. Interventions demonstrated small, statistically significant effects on biomarkers (-0.35, 95% CI: -0.48, -0.22, p < 0.001) and medium effects on mood outcomes (-0.50, 95% CI: -0.73, -0.27, p < 0.001), without evidence of substantive heterogeneity or publication bias. Individual analyses showed small effects for improved faecal calprotectin (-0.19, 95% CI: -0.34, -0.03, p = 0.018) and C-Reactive Protein (-0.29, 95% CI: -0.47, -0.10, p = 0.002). Effect sizes were larger for psychological therapy interventions (compared with exercise or antidepressants) and when there was an effect (SMD ≥0.2) on mood.

INTERPRETATION

Treatments which address mood outcomes have beneficial effects on generic inflammation as well as disease-specific biomarkers (faecal calprotectin and C-Reactive Protein). Psychological interventions and interventions with larger treatment effects on mood accentuated the effect on biomarkers. More research is required to understand the biological or behavioural mechanisms underlying this effect.

FUNDING

The Medical Research Council and the National Institute for Health and Care Research (NIHR) Maudsley Biomedical Research Centre.

The association between body weight indices, behavioral factors, and type 2 diabetes mellitus in Africa: A systematic review and meta-analysis of population-based epidemiological studies

BACKGROUND AND AIM

Type 2 diabetes mellitus (T2DM) is a significant public health concern in Africa. While the associations between modifiable risk factors and T2DM are likely to be Africa-specific, their overall estimations have not been published. This study aimed to use systematic and meta-analytic methods to examine the strength of associations between modifiable risk factors and T2DM in Africa.

METHODS AND RESULTS

A systematic search of literature published between January 2000 to March 2022 was conducted. The review included only population-based studies and data extracted from 57 studies. Of these, unadjusted data from 50 studies were included in meta-analysis. With considerable heterogeneity between studies, random-effect models were calculated to ascertain the odds ratios (OR) and 95% confidence intervals (CI) for the associations between obesity (OB) and overweight (OV), defined by BMI; central obesity (waist circumference (OB-WC), waist-to-hip-ratio (OB-WHR)), alcohol, fruit and vegetable consumption, smoking, physical activity (PA) and T2DM. Moderator effects of age, African regions, and urban/rural location were assessed. Risk factors associated with T2DM include BMI-OB [OR = 3.05, 95% CI: (2.58, 3.61)], BMI-OV [OR = 2.38, 95% CI: (1.51, 3.75)], and BMI-OV/OB [OR = 2.07, 95% CI: (1.82, 2.34)]; OB-WC [OR = 2.58, 95% CI: (2.09, 3.18)] and OB-WHR [OR = 2.22, 95% CI: (1.69, 2.92)]; PA [OR = 1.85, 95% CI: (1.50, 2.30)]. Significant moderator effects were not observed.

CONCLUSION

Obesity defined by BMI and central obesity, but not behavioral risk factors were most strongly associated with T2DM in African populations, emphasizing the need for obesity prevention to limit the rise of T2DM.

REGISTRATION

The PROSPERO registration number is CRD42016043027.

Effects of digital-based interventions on muscular strength in adults: a systematic review, meta-analysis and meta-regression of randomized controlled trials with quality of evidence assessment

BACKGROUND

In the last three decades, both medical and sports science professionals have recognized the considerable potential of digital-based interventions (DBI) to enhance the health-related outcomes of their practitioners.

OBJECTIVES

This study aimed to investigate the effectiveness and potential moderators of DBI on measures of muscular strength.

METHODS

Six databases (PubMed/MEDLINE, Web of Science, SportDiscus, Embase, Cochrane Register of Controlled Trials and Google Scholar) were searched for eligible studies up to June 2022. The GRADE, PEDRO, and TIDieR checklists were used to assess the quality of evidence, methodology, and completeness of intervention descriptions, respectively.

RESULTS

A total of 56 studies were included in the meta-analysis (n = 2346), and participants were classified as healthy (n = 918), stroke survivors (n = 572), diagnosed with other neurological disorders (n = 683), and frail (n = 173). The DBI showed a small effect (standardized mean difference [SMD] = 0.28, 95% CI 0.21 to 0.31; p < 0.001) on strength, regardless of the type of intervention, control group, or tested body part. More specifically, while splitting the studies into different subgroups, a meta-analysis of 19 studies (n = 918) showed a small effect (SMD = 0.38, 95% CI 0.12 to 0.63; p = 0.003) on strength in the asymptomatic population. Similarly, small but positive effects of DBI were observed for stroke survivors (SMD = 0.34, 95% CI 0.13 to 0.56; p = 0.002), patients diagnosed with other neurological disorders (SMD = 0.17, 95% CI 0.03 to 0.32; p = 0.021), and the frail population (SMD = 0.25, 95% CI 0.0 to 0.5; p = 0.051). Sub-group analysis and meta-regression revealed that neither variable modified the effects of the DBI on measures of strength.

CONCLUSIONS

Overall, DBI may serve as an effective method to improve measures of strength in adults, regardless of their health status as well as the type of digital device, the presence of human-computer interaction, and the age of participants. In addition, the DBI was found to be more effective than traditional training or rehabilitation methods.KEY MESSAGESDigital-based intervention (DBI) is effective in improving measures of muscular strength in adults regardless of participants' health statusDBIs were equally effective for strength improvements in lower and upper limbsAlthough, DBIs were found to be effective in improving muscular strength, most studies did not follow strength training guidelines when prescribing the interventions.

Augmentation therapy with serotonin1A receptor partial agonists on neurocognitive function in schizophrenia: A systematic review and meta-analysis

Background

In a previous meta-analysis, the use of serotonin1A(5-HT1A) receptor partial agonists of the azapirone class as an add-on therapy was associated with beneficial effects on positive symptoms and attention/processing speed in schizophrenia patients. This meta-analysis builds on that study by examining the effects of adjunctive treatment with 5-HT1A partial agonists in improving other domains of neurocognitive function in schizophrenia patients.

Methods

A literature search was performed from 1987 to May 2023 to identify randomized controlled trials. The standardized mean difference (SMD) with 95 % confidence intervals (CI) was calculated when there were two or more studies. Four studies, involving 313 patients, met the inclusion criteria and were used in the analysis.

Results

5-HT1A partial agonists (buspirone or tandospirone) did not have a significant effect on verbal learning (SMD = 0.08, 95 % CI = -0.31 to 0.47) or working memory (SMD = 0.15, 95 % CI = -0.09 to 0.39). Regarding executive functions (Wisconsin Card Sorting Test), positive but non-significant results were seen with the category number (SMD = 0.26, 95 % CI = -0.81 to 1.32), while non-significant effects were noted for percent preservation errors (SMD = -0.10, 95 % CI = -0.53 to 0.33).

Conclusions

The absence of any significant benefits in the cognitive domains studied here may have been due to the variance in the concomitant medication (typical vs atypical antipsychotic drugs), the level of cognition at baseline, or other factors. Further studies with various types of 5-HT1A agonists are warranted to examine the potential cognitive efficacy of stimulating these receptors.

Comparing body image dissatisfaction between pregnant women and non-pregnant women: a systematic review and meta-analysis

Body image dissatisfaction refers to negative thoughts and feelings individuals have towards their own body appearance and this is thought to be affected by the physiological changes that occur during pregnancy. There are two main conflicting theories as to the effect pregnancy has on body image dissatisfaction: 1) Pregnancy related changes are in direct conflict with social ideas of female beauty (e.g. weight gain) and so increase body image dissatisfaction; 2) Due to changes in expectations of bodily appearance during pregnancy, women are liberated from social ideals at this time and thus body image dissatisfaction would decrease. This study aimed to assess these theories by synthesising the current literature. Six databases were searched, and 2,017 study abstracts were screened based on strict inclusion and exclusion criteria. Following screening and quality assessment by two blind reviewers, 17 studies (comprising 17 effect sizes) were subject to full review and meta-analysis following PRISMA guidelines. These studies included cross-sectional, longitudinal and retrospective designs. Results varied with some studies showing women to feel more positive about their body during pregnancy, others showing a more negative body experience and yet others showing no statistical difference. Overall the analysis showed no statistical difference in body image dissatisfaction between pregnant women and non-pregnant women (p = 0.39). Any changes that do occur are heterogeneous and likely to be largely dependent on the individual experience as well as moderator variables and other factors such as differences in methodology of research studies. Studies in this field of research would benefit from more explicit and complete reporting of data and key variables, in order to allow early intervention for women who display body image dissatisfaction in pregnancy.

Association between negative parent-related family interactions and child social anxiety: A cross-cultural systematic review and meta-analysis

This meta-analysis systematically evaluates the strength and direction of the association between negative parent-related family interactions and child social anxiety, and identifies several influencing moderators. Two investigators independently searched international (PsycINFO, PubMed, and Web of Science) and Chinese (CNKI, WanFang, and VIP) databases from their inception dates until March 5, 2023, for suitable articles. Of the 5771 identified records, 85 studies were selected based on inclusion of at least one of the following three dimensions of negative family interactions: insecure attachment (n = 27), parent-related family conflicts (n = 19), or negative parenting styles (n = 46). Meta-analyses showed that all three dimensions were significantly associated with child social anxiety (insecure attachment: r = 0.271, p < 0.0001; parent-related family conflicts: r = 0.226, p < 0.0001; negative parenting styles: r = 0.186, p < 0.0001). For all three dimensions, this association was stronger in children from East Asian culture than in those from European or American culture. In addition, age group, information source, and publication year also significantly moderated this association. Our findings will help guide further research and provide recommendations for the development of effective interventions for reducing social anxiety.

Effects of vitamin D supplementation on maximal strength and power in athletes: a systematic review and meta-analysis of randomized controlled trials

Background

Vitamin D is thought to be a powerful modulator of skeletal muscle physiology. However, available data on the effects of vitamin D supplementation on muscle function in athletes are limited and with mixed results. This meta-analysis therefore, aimed to quantitatively summarize the up-to-date literature assessing the effects of vitamin D supplementation on muscle strength and power in athletes.

Methods

Sport Discus, PubMed, Cochrane Library and Web of Science were searched to identify randomized controlled trials (RCTs) that used one-repetition maximum (1RM) tests to assess maximal strength, and vertical jump to assess muscle power in athletes. The Cochrane Risk of Bias tool was used to evaluate the included RCTs for sources of bias. The standardized mean difference (SMD) was used as the effect size, interpreted together with its 95% confidence intervals (CI). The effect sizes were calculated on the changes from baseline between vitamin D and placebo groups for maximal strength results by upper body and lower body, and for power results.

Results

Eleven RCTs involving 436 athletes were included. The results indicated that if baseline serum 25(OH)D concentration was < 75 nmol/L, the treatment had a small effect on upper body muscle strength [SMD 0.25, 95% CI: (-0.44, 0.95), p = 0.47] and on lower body muscle strength [SMD 0.26, 95% CI: (-0.13, 0.65), p = 0.19]; if the baseline serum 25(OH)D concentration was ≥ 75 nmol/L, the treatment had a trivial effect on muscle power [SMD 0.15, 95% CI: (-0.42, 0.72), p = 0.61].

Discussion

This meta-analysis demonstrated that there is not a statistically significant effect of vitamin D supplementation on improving maximum strength and power, but highlights that further research is required addressing the key limitations in previous studies before definitive conclusions can be made.

Platelet count in preeclampsia: a systematic review and meta-analysis

OBJECTIVE

Many studies have reported the association between platelets and preeclampsia. However, sample sizes were small, and their findings were inconsistent. We conducted a systematic review and meta-analysis to evaluate the association in pooled samples and in detail.

DATA SOURCES

A systematic literature search was performed using Medline, Embase, ScienceDirect, Web of Science, Cochrane Library, NICHD-DASH, LILACS, and Scopus from inception to April 22, 2022.

STUDY ELIGIBILITY CRITERIA

Observational studies comparing platelet count between women with preeclampsia and normotensive pregnant women were included.

METHODS

The mean differences with 95% confidence interval in platelet count were calculated. Heterogeneity was assessed using I2 statistics. Sensitivity and subgroup analyses were conducted. Statistical analysis was performed using RevMan 5.3 and ProMeta 3 software.

RESULTS

A total of 56 studies comprising 4892 preeclamptic and 9947 normotensive pregnant women were included. Meta-analysis showed that platelet count was significantly lower in women with preeclampsia than in normotensive controls (overall: mean difference, -32.83; 95% confidence interval, -40.13 to -25.52; P<.00001; I2=92%; mild preeclampsia: mean difference, -18.65; 95% confidence interval, -27.17 to -10.14; P<.00001; I2=84%; severe preeclampsia: mean difference, -42.61; 95% confidence interval, -57.53 to -27.68; P<.00001; I2=94%). Significantly lower platelet count was also observed in the second trimester (mean difference, -28.84; 95% confidence interval, -44.59 to -13.08; P=.0003; I2=93%), third trimester (mean difference, -40.67; 95% confidence interval, -52.14 to -29.20; P<.00001; I2=92%), and before the diagnosis of preeclampsia (mean difference, -18.81; 95% confidence interval, -29.98 to -7.64; P=.009; I2=87%), but not in the first trimester (mean difference, -15.14; 95% confidence interval, -37.71 to 7.43; P=.19; I2=71%). Overall, the pooled sensitivity and specificity of platelet count were 0.71 and 0.77, respectively. The area under the curve was 0.80.

CONCLUSION

This meta-analysis confirmed that platelet count was significantly lower in preeclamptic women, irrespective of severity and presence or absence of associated complications, even before the onset of preeclampsia and in the second trimester of pregnancy. Our findings suggest that platelet count may be a potential marker to identify and predict preeclampsia.

Meta-Analyses of Reading Intervention Studies Including Students With Learning Disabilities: A Methodological Review

Learning disabilities (LD) may affect a range of academic skills but are most often observed in reading. Researchers and policymakers increasingly recommend addressing reading difficulties encountered by students with LD using evidence-based practices, or interventions validated through multiple, high-quality research studies. A valuable tool in identifying evidence-based practices is the meta-analysis, which entails statistically aggregating the results obtained through primary studies. Specific methods used in meta-analyses have the potential to influence their findings, with ramifications for research and practice. This review assessed the methodological features of the systematic reviews and analytic procedures featured in meta-analyses of reading intervention studies that included students with LD written between 2000 and 2020. Identified articles (N = 23) suggest that meta-analyses have become more prevalent and transparent over time, notwithstanding issues related to publication bias and the opacity of coding procedures. A discussion of implications follows a description of results.

The effects of positive psychology interventions on well-being and distress in patients with cardiovascular diseases: A systematic review and Meta-analysis

OBJECTIVE

Positive psychology interventions (PPIs) have been found to be effective for psychiatric and somatic disorders. However, a systematic review and meta-analysis of studies examining the effectiveness of PPIs for patients with cardiovascular disease (CVD) is lacking. This systematic review and meta-analysis aims to synthesize studies examining the effectiveness of PPIs and to examine their effects on mental well-being and distress using meta-analyses.

METHODS

This study was preregistered on OSF (https://osf.io/95sjg/). A systematic search was performed in PsycINFO, PubMed and Scopus. Studies were included if they examined the effectiveness of PPIs on well-being for patients with CVD. Quality assessment was based on the Cochrane tool for assessing risk of bias. Three-level mixed-effects meta-regression models were used to analyze effect sizes of randomized controlled trials (RCTs).

RESULTS

Twenty studies with 1222 participants were included, of which 15 were RCTs. Included studies showed high variability in study and intervention characteristics. Meta-analyses showed significant effects for mental well-being (β = 0.33) and distress (β = 0.34) at post-intervention and the effects were still significant at follow-up. Five of the 15 RCTs were classified as having fair quality, while the remaining had low quality.

CONCLUSION

These results suggest that PPIs are effective in improving well-being and distress in patients with CVD and could therefore be a valuable addition for clinical practice. However, there is a need for more rigorous studies that are adequately powered and that help us understand what PPIs are most effective for which patient.

Addiction as a brain disease? A meta-regression comparison of error-related brain potentials between addiction and neurological diseases

The notion that addiction is a "brain disorder" is widespread. However, there is a lack of evidence on the degree of disorder in terms of error processing in addiction. The present meta-analysis aimed at shedding light on this by comparing error-processes with populations with well-recognized brain disorders. We included 17 addiction and 32 neurological disorder studies that compared error-related negativity (ERN) or error positivity (Pe) amplitudes/latencies between experimental and healthy-control groups. Meta-regression analyses were performed for the intergroup comparison and other moderators. Both diagnoses were accompanied by a diminished ERN amplitude, although the degree of impairment was marginally larger in neurological disorders. Neurological disorders presented shorter ERN latencies than addiction when compared with controls. The two groups did not differ in Pe amplitude/latency. Except for a reduced ERN amplitude found along with aging, no other moderator contributed significantly to divergent findings about these four ERP indexes. The results support the brain disease model of addiction, while stressing the importance of quantifying the degrees of brain dysfunctions as a next step.

The Influence of Diagnostic Labels on the Evaluation of Students: a Multilevel Meta-Analysis

Research suggests that children suffering from different types of disorders (learning disorders, behavioral disorders, or intellectual disabilities) are sometimes evaluated differently simply due to the presence of a diagnostic label. We conducted a multilevel meta-analysis of experimental studies (based on data from 8,295 participants and on 284 effects nested in 60 experiments) to examine the magnitude and robustness of such label effects and to explore the impact of potential moderators (type of evaluation, diagnostic category, expertise, student’s gender, and amount and type of information). We found a moderately negative overall label effect (Hedges’ g = −0.42), which was robust across several types of evaluation, different samples, and different diagnostic categories. There was no indication that expertise and the gender of the child moderated the effect. Presenting participants with only a label yielded the strongest negative effect of g = −1.26, suggesting that the effect was dependent on the amount of information being presented to participants. We conclude that labeling a child can exacerbate negative academic evaluations, behavioral evaluations, evaluations of personality, and overall assessments of the child. Further implications for theory and future research are discussed.

Are Brain Responses to Emotion a Reliable Endophenotype of Schizophrenia? An Image-Based Functional Magnetic Resonance Imaging Meta-analysis

BACKGROUND

Impaired emotion processing constitutes a key dimension of schizophrenia and a possible endophenotype of this illness. Empirical studies consistently report poorer emotion recognition performance in patients with schizophrenia as well as in individuals at enhanced risk of schizophrenia. Functional magnetic resonance imaging studies also report consistent patterns of abnormal brain activation in response to emotional stimuli in patients, in particular, decreased amygdala activation. In contrast, brain-level abnormalities in at-risk individuals are more elusive. We address this gap using an image-based meta-analysis of the functional magnetic resonance imaging literature.

METHODS

Functional magnetic resonance imaging studies investigating brain responses to negative emotional stimuli and reporting a comparison between at-risk individuals and healthy control subjects were identified. Frequentist and Bayesian voxelwise meta-analyses were performed separately, by implementing a random-effect model with unthresholded group-level T-maps from individual studies as input.

RESULTS

In total, 17 studies with a cumulative total of 677 at-risk individuals and 805 healthy control subjects were included. Frequentist analyses did not reveal significant differences between at-risk individuals and healthy control subjects. Similar results were observed with Bayesian analyses, which provided strong evidence for the absence of meaningful brain activation differences across the entire brain. Region of interest analyses specifically focusing on the amygdala confirmed the lack of group differences in this region.

CONCLUSIONS

These results suggest that brain activation patterns in response to emotional stimuli are unlikely to constitute a reliable endophenotype of schizophrenia. We suggest that future studies instead focus on impaired functional connectivity as an alternative and promising endophenotype.

The impact of violating the independence assumption in meta-analysis on biomarker discovery

With rapid advancements in high-throughput sequencing technologies, massive amounts of "-omics" data are now available in almost every biomedical field. Due to variance in biological models and analytic methods, findings from clinical and biological studies are often not generalizable when tested in independent cohorts. Meta-analysis, a set of statistical tools to integrate independent studies addressing similar research questions, has been proposed to improve the accuracy and robustness of new biological insights. However, it is common practice among biomarker discovery studies using preclinical pharmacogenomic data to borrow molecular profiles of cancer cell lines from one study to another, creating dependence across studies. The impact of violating the independence assumption in meta-analyses is largely unknown. In this study, we review and compare different meta-analyses to estimate variations across studies along with biomarker discoveries using preclinical pharmacogenomics data. We further evaluate the performance of conventional meta-analysis where the dependence of the effects was ignored via simulation studies. Results show that, as the number of non-independent effects increased, relative mean squared error and lower coverage probability increased. Additionally, we also assess potential bias in the estimation of effects for established meta-analysis approaches when data are duplicated and the assumption of independence is violated. Using pharmacogenomics biomarker discovery, we find that treating dependent studies as independent can substantially increase the bias of meta-analyses. Importantly, we show that violating the independence assumption decreases the generalizability of the biomarker discovery process and increases false positive results, a key challenge in precision oncology.

Meta-analyzing individual participant data from studies with complex survey designs: A tutorial on using the two-stage approach for data from educational large-scale assessments

Descriptive analyses of socially important or theoretically interesting phenomena and trends are a vital component of research in the behavioral, social, economic, and health sciences. Such analyses yield reliable results when using representative individual participant data (IPD) from studies with complex survey designs, including educational large-scale assessments (ELSAs) or social, health, and economic survey and panel studies. The meta-analytic integration of these results offers unique and novel research opportunities to provide strong empirical evidence of the consistency and generalizability of important phenomena and trends. Using ELSAs as an example, this tutorial offers methodological guidance on how to use the two-stage approach to IPD meta-analysis to account for the statistical challenges of complex survey designs (e.g., sampling weights, clustered and missing IPD), first, to conduct descriptive analyses (Stage 1), and second, to integrate results with three-level meta-analytic and meta-regression models to take into account dependencies among effect sizes (Stage 2). The two-stage approach is illustrated with IPD on reading achievement from the Programme for International Student Assessment (PISA). We demonstrate how to analyze and integrate standardized mean differences (e.g., gender differences), correlations (e.g., with students' socioeconomic status [SES]), and interactions between individual characteristics at the participant level (e.g., the interaction between gender and SES) across several PISA cycles. All the datafiles and R scripts we used are available online. Because complex social, health, or economic survey and panel studies share many methodological features with ELSAs, the guidance offered in this tutorial is also helpful for synthesizing research evidence from these studies.

Child executive function and future externalizing and internalizing problems: A meta-analysis of prospective longitudinal studies

To determine the association between executive function and later externalizing and internalizing problems, we conducted a meta-analysis of 167 studies (1098 effect sizes, total N = 66,119) that explored the longitudinal associations between executive functions in children and subsequent externalizing and internalizing problems. The results indicated that greater child executive function was prospectively associated with fewer attention-deficit/hyperactivity disorder (ADHD) symptoms, fewer conduct problems, fewer oppositional defiant disorder symptoms, less substance use, fewer broad externalizing problems, fewer depression symptoms, and fewer broad internalizing problems, but not with subsequent anxiety symptoms. Moderator analyses revealed that the sample type moderated the associations of executive function with both ADHD symptoms and conduct problems. Age of assessment moderated the association with broad externalizing problems, and executive function context moderated associations with both substance use and broad internalizing problems. These findings suggest that executive function in children prospectively predicts numerous externalizing and internalizing behaviors, suggesting that executive function may be an important target for psychopathology prevention programs and interventions.

The relationships between social support and loneliness: A meta-analysis and review

The loneliness of modern people is becoming more and more prominent, and has brought profoundly negative effects on mental health. Social support is an important predictor of loneliness. However, the size of the correlation reported by studies on the relation between social support and loneliness varies greatly. The aim of this meta-analysis is to determine the relation between social support and loneliness. One hundred and seventy-seven articles (N = 113,427) were identified, and robust variance estimation with random effects were used. As expected, higher levels of social support were negatively correlated with loneliness (r = -0.39). The association between social support and loneliness were also moderated by several variables. Specifically, the negative relationship between loneliness and social support among rural populations is stronger than that of urban populations in Chinese samples, the effect of perceived social support (r = -0.45) on loneliness is greater than that of other social supports (r = -0.36), and the friend support (r = -0.48) played a more important role in reducing loneliness than that of two other supports (family support: r = -0.34; significant other support: r = -0.40). The current results support robust links between social support and loneliness, emphasizing the important role of social support in reducing levels of loneliness, this may have some implications for future research and loneliness treatments.

A Systematic Review and Meta-Analysis on the Association and Differences between Aerobic Threshold and Point of Optimal Fat Oxidation

Over the past two decades, scientists have attempted to evaluate whether the point of maximal fat oxidation (FATmax) and the aerobic threshold (AerT) are connected. The existence of such a relationship would allow a more tailored training approach for athletes while improving the efficacy of individualized exercise prescriptions when treating numerous health-related issues. However, studies have reported conflicting results, and this issue remains unresolved. This systematic review and meta-analysis aimed: (i) to examine the strength of the association between FATmax and AerT by using the effect size (ES) of correlation coefficient (r) and standardized mean difference (SMD); (ii) to identify potential moderators and their influence on ES variability. This study was registered with PROSPERO (CRD42021239351) and ClinicalTrials (NCT03789045). PubMed and Google Scholar were searched and fourteen articles, consisting of overall 35 ES for r and 26 ES for SMD were included. Obtained ESs were analyzed using a multilevel random-effects meta-analysis. Our results support the presence of a significant association between FATmax and AerT exercise intensities. In conclusion, due to the large ES variance caused by clinical and methodological differences among the studies, we recommend that future studies follow strict standardization of data collection and analysis of FATmax and AerT-related outcomes.

Can Compression Garments Reduce the Deleterious Effects of Physical Exercise on Muscle Strength? A Systematic Review and Meta-Analyses

Background

The use of compression garments (CGs) during or after training and competition has gained popularity in the last few decades. However, the data concerning CGs’ beneficial effects on muscle strength-related outcomes after physical exercise remain inconclusive.

Objective

The aim was to determine whether wearing CGs during or after physical exercise would facilitate the recovery of muscle strength-related outcomes.

Methods

A systematic literature search was conducted across five databases (PubMed, SPORTDiscus, Web of Science, Scopus, and EBSCOhost). Data from 19 randomized controlled trials (RCTs) including 350 healthy participants were extracted and meta-analytically computed. Weighted between-study standardized mean differences (SMDs) with respect to their standard errors (SEs) were aggregated and corrected for sample size to compute overall SMDs. The type of physical exercise, the body area and timing of CG application, and the time interval between the end of the exercise and subsequent testing were assessed.

Results

CGs produced no strength-sparing effects (SMD [95% confidence interval]) at the following time points (t) after physical exercise: immediately ≤ t < 24 h: − 0.02 (− 0.22 to 0.19), p = 0.87; 24 ≤ t < 48 h: − 0.00 (− 0.22 to 0.21), p = 0.98; 48 ≤ t < 72 h: − 0.03 (− 0.43 to 0.37), p = 0.87; 72 ≤ t < 96 h: 0.14 (− 0.21 to 0.49), p = 0.43; 96 h ≤ t: 0.26 (− 0.33 to 0.85), p = 0.38. The body area where the CG was applied had no strength-sparing effects. CGs revealed weak strength-sparing effects after plyometric exercise.

Conclusion

Meta-analytical evidence suggests that wearing a CG during or after training does not seem to facilitate the recovery of muscle strength following physical exercise. Practitioners, athletes, coaches, and trainers should reconsider the use of CG as a tool to reduce the effects of physical exercise on muscle strength.

Trial Registration Number

PROSPERO CRD42021246753.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40279-022-01681-4.

Accuracy and Precision of Energy Expenditure, Heart Rate, and Steps Measured by Combined-Sensing Fitbits Against Reference Measures: Systematic Review and Meta-analysis

BACKGROUND

Although it is widely recognized that physical activity is an important determinant of health, assessing this complex behavior is a considerable challenge.

OBJECTIVE

The purpose of this systematic review and meta-analysis is to examine, quantify, and report the current state of evidence for the validity of energy expenditure, heart rate, and steps measured by recent combined-sensing Fitbits.

METHODS

We conducted a systematic review and Bland-Altman meta-analysis of validation studies of combined-sensing Fitbits against reference measures of energy expenditure, heart rate, and steps.

RESULTS

A total of 52 studies were included in the systematic review. Among the 52 studies, 41 (79%) were included in the meta-analysis, representing 203 individual comparisons between Fitbit devices and a criterion measure (ie, n=117, 57.6% for heart rate; n=49, 24.1% for energy expenditure; and n=37, 18.2% for steps). Overall, most authors of the included studies concluded that recent Fitbit models underestimate heart rate, energy expenditure, and steps compared with criterion measures. These independent conclusions aligned with the results of the pooled meta-analyses showing an average underestimation of -2.99 beats per minute (k comparison=74), -2.77 kcal per minute (k comparison=29), and -3.11 steps per minute (k comparison=19), respectively, of the Fitbit compared with the criterion measure (results obtained after removing the high risk of bias studies; population limit of agreements for heart rate, energy expenditure, and steps: -23.99 to 18.01, -12.75 to 7.41, and -13.07 to 6.86, respectively).

CONCLUSIONS

Fitbit devices are likely to underestimate heart rate, energy expenditure, and steps. The estimation of these measurements varied by the quality of the study, age of the participants, type of activities, and the model of Fitbit. The qualitative conclusions of most studies aligned with the results of the meta-analysis. Although the expected level of accuracy might vary from one context to another, this underestimation can be acceptable, on average, for steps and heart rate. However, the measurement of energy expenditure may be inaccurate for some research purposes.

Food-Specific Inhibition Training for Food Devaluation: A Meta-Analysis

Theories have suggested that food-specific inhibition training could lead to food devaluation which, in turn, may help people to regulate their eating behavior. In this review, we have synthesized the current literature on this topic by conducting a meta-analysis of studies investigating the effects of food-specific inhibition training on food evaluation. We identified 24 studies-with 36 independent samples, 77 effect sizes, and 3032 participants-that met our inclusion criteria. Effect sizes were analyzed using the robust variance estimation in random effects meta-regression technique. The results indicate that food-specific inhibition training can lead to statistically significant reductions in food evaluation. More specifically, it was observed that the effects of training on participants' food evaluation differed according to the type of evaluation; food-specific inhibition training significantly decreased participants' explicit food evaluation, but not their implicit food evaluation. However, because most of the included studies focused on trained food items and short-term outcomes in normal-weight samples, more research is needed on the continuance of the training effects, as well as on the extent to which effects can be generalized to untrained food items or different populations (e.g., overweight or obese individuals).

Social cognition in children and adolescents with epilepsy: A meta-analysis

Many studies have investigated impairments in two key domains of social cognition (theory of mind [ToM] and facial emotion recognition [FER]) in children and adolescents with epilepsy. However, inconsistent conclusions were found. Our objective was to characterize social cognition performance of children and adolescents with epilepsy. A literature search was conducted using Web of Science, PubMed, and Embase databases. The article retrieval, screening, quality assessment (Newcastle-Ottawa-Scale), and data extraction were performed independently by two investigators. A random-effects model was used to examine estimates. The meta-analysis included 19 studies, with a combined sample of 623 children and adolescents with epilepsy (mean [SD] age, 12.13 [2.62] years; 46.1% female) and 677 healthy controls [HCs]) (mean [SD] age, 11.48 [2.71] years; 50.7% female). The results revealed that relative to HCs, children and adolescents with epilepsy exhibited deficits in ToM (g = -1.08, 95% CI [-1.38, -0.78], p < 0.001, the number of studies [k] = 13), FER (g = -0.98, 95% CI [-1.33, -0.64], p < 0.001, k = 12), and ToM subcomponents (cognitive ToM: g = -1.04, 95% CI [-1.35, -0.72], p < 0.001, k = 12] and affective ToM: g = -0.73, 95% CI [-1.12, -0.34], p < 0.001, k = 8). In addition, there were no statistically significant differences in social cognition deficits between children and adolescents with focal epilepsy and generalized epilepsy. Meta-regressions confirmed the robustness of the results. These quantitative results further deepen our understanding of the two core domains of social cognition in children and adolescents with epilepsy and may assist in the development of cognitive interventions for this patient population. Systematic review registration: https://inplasy.com/inplasy-2022-3-0011/, identifier INPLASY202230011.

Theory of mind and facial emotion recognition in adults with temporal lobe epilepsy: A meta-analysis

BACKGROUND

Mounting studies have investigated impairments in social cognitive domains (including theory of mind [ToM] and facial emotion recognition [FER] in adult patients with temporal lobe epilepsy (TLE). However, to date, inconsistent findings remain.

METHODS

A search of PubMed, Web of Science, and Embase databases was conducted until December 2021. Hedges g effect sizes were computed with a random-effects model. Meta-regressions were used to assess the potential confounding factors of between-study variability in effect sizes.

RESULTS

The meta-analysis included 41 studies, with a combined sample of 1,749 adult patients with TLE and 1,324 healthy controls (HCs). Relative to HCs, adult patients with TLE showed large impairments in ToM (g = -0.92) and cognitive ToM (g = -0.92), followed by medium impairments in affective ToM (g = -0.79) and FER (g = -0.77). Besides, no (statistically) significant differences were observed between the magnitude of social cognition impairment in adult with TLE who underwent and those who did not undergo epilepsy surgery. Meta-regressions exhibited that greater severity of executive functioning was associated with more severe ToM defects, and older age was associated with more severe FER defects.

CONCLUSIONS

Results of this meta-analysis suggest that adult patients with TLE show differential impairments in the core aspects of social cognitive domains (including ToM and FER), which may help in planning individualized treatment with appropriate cognitive and behavioral interventions.

Reward-related decision-making deficits in internet gaming disorder: a systematic review and meta-analysis

AIMS

To estimate the aggregated effect sizes of reward-related decision-making deficits in internet gaming disorder (IGD) and to explore potential moderators on the variability of effect sizes across studies.

DESIGN

Review of peer-reviewed studies comparing reward-related decision-making performance between IGD and control participants identified via PubMed, Web of Science and ProQuest databases. Random-effects modeling was conducted using Hedge's g as the effect size (ES). The effects of decision-making situation, valence, sample type, testing environment, IGD severity and self-reported impulsivity on decision-making differences were examined by moderator analyses.

SETTING

No restrictions on location.

PARTICIPANTS

Twenty-four studies (20 independent samples) were included in the meta-analysis, resulting in 604 IGD and 641 control participants and 35 ESs.

MEASURES

Reward-related decision-making differences between IGD and control groups.

FINDINGS

The overall ES for decision-making deficits in IGD was small (g = -0.45, P < 0.01). The effects were comparable across risky, ambiguous and inter-temporal decision-making. Larger aggregate ESs were identified for pure-gain and mixed compared with pure-loss decision-making. Studies based on clinical and community samples showed similar effects. No significant difference between behavioral studies and those with extra measurements was observed. Decision-making alterations were not closely associated with IGD severity or self-reported impulsivity differences at the study level.

CONCLUSIONS

Internet gaming disorder appears to be consistently associated with reward-related decision-making deficits.

Theory of Mind and Empathy in Adults With Epilepsy: A Meta-Analysis

Mounting evidence suggests that social cognitive abilities [including theory of mind (ToM) and empathy] are impaired in adult patients with epilepsy. Although the deficits in overall ToM in epilepsy have been documented well, the effects of epilepsy on empathic ability and specific subcomponents of ToM remain unclear. The primary aim of this study was to provide the first meta-analytic integration of ToM and empathy in adult patients with epilepsy, and to decompose these constructs to clearly differentiate their distinct (cognitive ToM and affective empathy) and overlapping (affective ToM/cognitive empathy) components. This meta-analysis included 28 studies. Adult patients with temporal lobe epilepsy (TLE) and frontal lobe epilepsy (FLE) showed impairments in cognitive ToM and affective ToM/cognitive empathy compared to the healthy controls (HCs); no group differences were identified for affective empathy. Besides, cognitive ToM was impaired in adult patients with idiopathic generalized epilepsy (IGE) and focal seizures (caused by epileptogenic foci) outside the temporal and frontal lobes (extra-TLE/FLE) and no group differences were evident for affective ToM/cognitive empathy compared to the HCs. Moreover, relative to the HCs, no group differences were identified for affective empathy in adult patients with IGE. Additionally, no (statistically) significant difference was observed between the magnitude of ToM/empathy impairment in adult patients who underwent and those who did not undergo epilepsy surgery. These quantitative findings suggest differential impairment of the core aspects of social cognitive processing in adult patients with epilepsy, which may contribute to the development of structured cognitive interventions (i.e., social cognitive training) for adult patients with epilepsy.

Does older adults' cognition particularly suffer from stress? A systematic review of acute stress effects on cognition in older age

This literature review provides the first comprehensive qualitative and quantitative systematic synthesis of acute laboratory stress effects on older adults' cognition by specifying the direction and magnitude of those effects both overall and for different cognitive processes separately. A systematic literature search was performed, and effect sizes estimated whenever possible. We found meta-analytical evidence that stress has negative effects on older adults' verbal fluency (g_adj = -0.53, 95 % CI [-2.70, 1.63]), null-to-negative effects on episodic memory (g_adj = -0.26, 95 % CI [-0.44, -0.08]), null effects on executive functions (g_adj = 0.07, 95 % CI [-0.31, 0.46]), and enhancing effects on working memory (g_adj = 0.16, 95 % CI [-0.01, 0.33]). Relating these findings to those in young adults, notable differences emerged for some cognitive functions, such as opposing effects on working memory between age groups. Our review further reveals that stress effects on older adults' memory retention, associative memory, prospective memory, interference control or cognitive flexibility are heavily understudied. We provide a conceptual and methodological framework for future studies in older adults.

Executive functions in children with heart disease: a systematic review and meta-analysis

CONTEXT

People with CHD are at increased risk for executive functioning deficits. Meta-analyses of these measures in CHD patients compared to healthy controls have not been reported.

OBJECTIVE

To examine differences in executive functions in individuals with CHD compared to healthy controls.

DATA SOURCES

We performed a systematic review of publications from 1 January, 1986 to 15 June, 2020 indexed in PubMed, CINAHL, EMBASE, PsycInfo, Web of Science, and the Cochrane Library.

STUDY SELECTION

Inclusion criteria were (1) studies containing at least one executive function measure; (2) participants were over the age of three.

DATA EXTRACTION

Data extraction and quality assessment were performed independently by two authors. We used a shifting unit-of-analysis approach and pooled data using a random effects model.

RESULTS

The search yielded 61,217 results. Twenty-eight studies met criteria. A total of 7789 people with CHD were compared with 8187 healthy controls. We found the following standardised mean differences: -0.628 (-0.726, -0.531) for cognitive flexibility and set shifting, -0.469 (-0.606, -0.333) for inhibition, -0.369 (-0.466, -0.273) for working memory, -0.334 (-0.546, -0.121) for planning/problem solving, -0.361 (-0.576, -0.147) for summary measures, and -0.444 (-0.614, -0.274) for reporter-based measures (p < 0.001).

LIMITATIONS

Our analysis consisted of cross-sectional and observational studies. We could not quantify the effect of collinearity.

CONCLUSIONS

Individuals with CHD appear to have at least moderate deficits in executive functions. Given the growing population of people with CHD, more attention should be devoted to identifying executive dysfunction in this vulnerable group.

Adjunctive multi-session transcranial direct current stimulation for neurocognitive dysfunction in schizophrenia: A meta-analysis

Findings of multi-session transcranial direct current stimulation (tDCS) as an adjunctive treatment of neurocognitive dysfunction in schizophrenia have been inconsistent. This meta-analysis of randomized controlled trials (RCTs) investigated the neurocognitive effects of adjunctive multi-session tDCS for schizophrenia. Twelve RCTs covering 418 schizophrenia patients were included and analyzed in this meta-analysis. The RevMan software (Version 5.3) was used to calculate risk ratios (RRs) and standardized mean differences (SMDs) with their 95% confidence intervals (CIs). Adjunctive tDCS outperformed the comparator in improving working memory deficits (SMD = 0.34, 95% CI: 0.03, 0.65; I² = 52%; p = 0.03), but no significant effects were found in other cognitive domains. No group differences were found with regard to total psychopathology measured by the Brief Psychiatric Rating Scale and the Positive and Negative Symptom Scale (SMD =-0.29, 95%CI: -0.61, 0.03; I² = 50%, p = 0.07) and discontinuation due to any reason (RR=0.80, 95%CI: 0.39, 1.66; I² = 9%, p = 0.56). Adjunctive tDCS appears to have a significant therapeutic effect improving the working memory deficits in schizophrenia.

Executive functioning as a predictor of physiological and subjective acute stress responses in non-clinical adult populations: A systematic literature review and meta-analysis

The goal of this systematic review and meta-analysis was to evaluate whether executive functioning predicts subsequent acute stress responses. A systematic search (conducted between May 22nd and 30th, 2019; updated on April 4th, 2020) on Cochrane, OpenGray, Proquest Dissertations and Thesis Global, PsycInfo, Pubmed, Scopus, and Web of Science revealed 27 correlational and five interventional studies. For quality appraisal, we used the BIOCROSS Tool, the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies, and the Revised Cochrane Risk-of-bias Tool for Randomized Trials. Attentional control was most consistently associated with acute stress. A robust variation estimation meta-analysis, conducted when sufficient data was available, revealed a small, significant, and negative correlation between higher working memory and subsequent lower cortisol reactivity (r = .09, p = .025, 95 % CI [0.15, 0.02]). These results highlight the role of executive functioning for acute stress responses, the scarcity of relevant data, and the need for both interventional designs and the consideration of mediators and moderators to understand underlying mechanisms.

Effects of non-invasive brain stimulation on visual perspective taking: A meta-analytic study

Visual perspective taking (VPT) is a critical ability required by complex social interaction. Non-invasive brain stimulation (NIBS) has been increasingly used to examine the causal relationship between brain activity and VPT, yet with heterogeneous results. In the current study, we conducted two meta-analyses to examine the effects of NIBS of the right temporoparietal junction (rTPJ) or dorsomedial prefrontal cortex (dmPFC) on VPT, respectively. We performed a comprehensive literature search to identify qualified studies and computed the standardized effect size (ES) for each combination of VPT level (Level-1: visibility judgment; Level-2: mental rotation) and perspective (self and other). Thirteen studies (rTPJ: 12 studies, 23 ESs; dmPFC: 4 studies, 14 ESs) were included in the meta-analyses. Random-effects models were used to generate the overall effects. Subgroup analyses for distinct VPT conditions were also performed. We found that rTPJ stimulation significantly improved participants' visibility judgment from the allocentric perspective, whereas its effects on other VPT conditions are negligible. Stimulation of dmPFC appeared to influence Level-1 performance from the egocentric perspective, although this finding was only based on a small number of studies. Notably, contrary to some theoretical models, we did not find strong evidence that these regions are involved in Level-2 VPT with a higher requirement of mental rotation. These findings not only advance our understanding of the causal roles of the rTPJ and dmPFC in VPT, but also reveal that the efficacy of NIBS on VPT is relatively small. Additionally, researchers should also be cautious about the potential publication bias and selective reporting.

A systematic review and meta-analysis of the association between expressive suppression and positive affect

People differ in their self-reported propensities to experience positive affect (PA). Even those prone to internalizing symptoms show varied proclivities to PA; social anxiety (SA), for instance, unlike other types of anxiety, shows a strong negative association with PA that cannot be explained by diminished reward sensitivity. Heightened reliance on suppression of emotional displays (expressive suppression; ES) may be an alternate contributor to attenuated PA among people with elevated SA, relative to people with other types of anxiety. A first step toward testing this hypothesis is clarifying the ES-PA association and examining whether it varies as a function of anxiety type (social anxiety vs. other types of anxiety). This meta-analysis (k = 41; n = 11,010) revealed a significant, negative association between ES and PA (r = -0.158); however, this relationship was not significant for individuals with social or other anxiety disorders. Moreover, two moderators (sample culture-Western: r = -0.16; Eastern: r = 0.003; type of emotion suppressed-Negative: r = 0.18; Positive: r = -0.12) accounted for significant heterogeneity in effect sizes. This review synthesizes the literature on ES and PA in healthy and anxious samples; findings suggest moderating variables merit closer attention in future studies.

Management of social isolation and loneliness in community-dwelling older adults: protocol for a network meta-analysis of randomised controlled trials

INTRODUCTION

Social isolation and loneliness in older adults are significant public health issues. Various interventions such as exercise programmes or social activities are used in the management of social isolation and loneliness in older adults. Network meta-analysis (NMA) provides effect estimates for all comparisons by considering the relative efficacy of multiple intervention alternatives. Therefore, this study will determine the comparative efficacy of intervention to alleviate social isolation and loneliness of older adults in community dwelling by comparing direct and indirect interventions through systematic review and NMA.

METHODS AND ANALYSIS

We will include all relevant randomised controlled trials for interventions of social isolation and loneliness in older adults written in English without any limitation of publication date through electronic databases: MEDLINE via OVID, EMBASE, Cochrane Central Registry of Controlled Trials (CENTRAL), PsycINFO and CINAHL. Independent teams of reviewers will screen trial eligibility, collect data, identify duplication and assess risk of bias, by using the Cochrane revised risk of bias tool. The interventions for the management of social isolation and loneliness will be included. The primary outcome is social isolation. The secondary outcomes are loneliness and health-related quality of life. We will conduct an NMA through a Bayesian hierarchical model, by testing assumption (ie, transitivity) for NMA. We will also estimate the ranking probabilities for all interventions at each possible rank for each intervention. For estimation of each intervention efficacy, we will assess the certainty and credibility using the Grading of Recommendations Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION

Ethics approval will not be obtained for this systematic review as it will be conducted with published papers. The review results will be presented at a field-specific conference and published in a relevant peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42020155789.

The role of visual-spatial attention in reading development: a meta-analysis

The association between visual attention and reading development has been investigated as a possible core causal deficit in dyslexia, in addition to phonological awareness. This study aims to provide a meta-analytic review of the research on attentional processes and their relation to reading development, to examine the possible influence on it of orthographic depth, age, and attentional tasks (interpreted as serial or parallel processing indices). We included studies with participants up to 18 years of age that have considered the visual spatial attention orienting that sustains the serial visual analysis involved in the phonological pathway of decoding, and the visual attention span that supports the multielement parallel processing that is thought to influence lexical decoding. The results confirm a strong association between visual attention and reading development; we evaluate the evidence and discuss the possibility that visual attention processes play a causal role in determining individual differences in reading acquisition.

Is eating a mixed diet better for health and survival?: A systematic review and meta-analysis of longitudinal observational studies

The role of dietary diversity in chronic disease or survival is controversial. This meta-analysis quantified the health impact of dietary diversity. Random-effects models pooled risk ratios (RRs) and 95% confidence intervals (CIs) of 20 longitudinal studies. Total dietary diversity was associated with a 22% lower risk of all-cause mortality (RR 0.78 [95%CI: 0.64, 0.96]), and was inversely associated with incident cancer- or CVD-specific mortality only in subgroup analyses (RR range: 0.53 to 0.90, p < 0.05). Similarly, diversity across healthy foods was inversely associated with all-cause mortality (RR 0.84 [95%CI: 0.73, 0.96]). An inverse association between total diet diversity and incident CVD was significant in non-European populations consuming diets with diverse food groups (RR: 0.93 [95% CI: 0.86-0.99]). Effects on cancer risk are unstudied. Diversity within fruits and/or vegetables showed null associations for all outcomes, except potentially for squamous cell-type carcinomas. More robust research is warranted. Findings indicated greater dietary diversity may benefit overall survival.

Mindfulness and Meditative Movement Interventions for Men Living With Cancer: A Meta-analysis

BACKGROUND

Mindfulness-based interventions, Tai Chi/Qigong, and Yoga (defined here as meditative cancer interventions [MCIs]) have demonstrated small to medium effects on psychosocial outcomes in female breast cancer patients. However, no summary exists of how effective these interventions are for men with cancer.

PURPOSE

A meta-analysis was performed to determine the effectiveness of MCIs on psychosocial outcomes (e.g., quality of life, depression, and posttraumatic growth) for men with cancer.

METHODS

A literature search yielded 17 randomized controlled trials (N = 666) meeting study inclusion criteria. The authors were contacted to request data for male participants in the study when not reported.

RESULTS

With the removal of one outlier, there was a small effect found in favor of MCIs across all psychosocial outcomes immediately postintervention (g = .23, 95% confidence interval [CI] 0.02 to 0.44). Studies using a usual care control arm demonstrated a small effect in favor of MCIs (g = .26, 95% CI 0.10 to 0.42). However, there was insufficient evidence of a superior effect for MCIs when compared to an active control group, including attention control. Few studies examined both short-term and long-term outcomes.

CONCLUSIONS

There is evidence for MCIs improving psychosocial outcomes in male cancer survivors. However, this effect is not demonstrated when limited to studies that used active controls. The effect size found in this meta-analysis is smaller than those reported in MCI studies of mixed gender and female cancer patient populations. More rigorously designed randomized trials are needed that include active control groups, which control for attention, and long-term follow-up. There may be unique challenges for addressing the psychosocial needs of male cancer patients that future interventions should consider.

A systematic review and meta-analysis of psychological interventions to improve mental wellbeing

Our current understanding of the efficacy of psychological interventions in improving mental states of wellbeing is incomplete. This study aimed to overcome limitations of previous reviews by examining the efficacy of distinct types of psychological interventions, irrespective of their theoretical underpinning, and the impact of various moderators, in a unified systematic review and meta-analysis. Four-hundred-and-nineteen randomized controlled trials from clinical and non-clinical populations (n = 53,288) were identified for inclusion. Mindfulness-based and multi-component positive psychological interventions demonstrated the greatest efficacy in both clinical and non-clinical populations. Meta-analyses also found that singular positive psychological interventions, cognitive and behavioural therapy-based, acceptance and commitment therapy-based, and reminiscence interventions were impactful. Effect sizes were moderate at best, but differed according to target population and moderator, most notably intervention intensity. The evidence quality was generally low to moderate. While the evidence requires further advancement, the review provides insight into how psychological interventions can be designed to improve mental wellbeing.

The Association Between Health Care Staff Engagement and Patient Safety Outcomes: A Systematic Review and Meta-Analysis

OBJECTIVES

Despite decades of research, improving health care safety remains a global priority. Individual studies have demonstrated links between staff engagement and care quality, but until now, any relationship between engagement and patient safety outcomes has been more speculative. This systematic review and meta-analysis therefore assessed this relationship and explored if the way these variables were defined and measured had any differential effect.

METHODS

After systematic searches of Medline, CINAHL, PsycInfo, Embase, Cochrane Library, and National Institute for Health Research Journals databases, narrative and random-effects meta-analyses were completed, with pooled effect sizes expressed as Pearson r.

RESULTS

Fourteen studies met the inclusion criteria, 11 of which were suitable for meta-analysis. Meta-analyses indicated a small but consistent, statistically significant relationship between staff engagement and patient safety (all outcomes; 11 studies; r = 0.22; 95% confidence interval [CI], 0.07 to 0.36; n = 30,490) and 2 patient safety outcome categories: patient safety culture (7 studies; r = 0.22; 95% CI, 0.01 to 0.41; n = 27,857) and errors/adverse events (4 studies; r = -0.20; 95% CI, -0.26 to -0.13; n = 2633). The specific approach to conceptualizing engagement did not affect the strength of the findings.

CONCLUSIONS

This is the first review to demonstrate a significant relationship between engagement and both safety culture scores and errors/adverse events. Despite a limited and evolving evidence base, we cautiously conclude that increasing staff engagement could be an effective means of enhancing patient safety. Further research is needed to determine causality and clarify the nature of the staff engagement/patient safety relationship at individual and unit/workgroup levels.

Characteristics and quality of systematic reviews and meta-analyses of observational nutritional epidemiology: a cross-sectional study

BACKGROUND

Dietary recommendations and policies should be guided by rigorous systematic reviews. Reviews that are of poor methodological quality may be ineffective or misleading. Most of the evidence in nutrition comes from nonrandomized studies of nutritional exposures (usually referred to as nutritional epidemiology studies), but to date methodological evaluations of the quality of systematic reviews of such studies have been sparse and inconsistent.

OBJECTIVES

We aimed to investigate the quality of recently published systematic reviews and meta-analyses of nutritional epidemiology studies and to propose guidance addressing major limitations.

METHODS

We searched MEDLINE (January 2018-August 2019), EMBASE (January 2018-August 2019), and the Cochrane Database of Systematic Reviews (January 2018-February 2019) for systematic reviews of nutritional epidemiology studies. We included a random sample of 150 reviews.

RESULTS

Most reviews were published by authors from Asia (n = 49; 32.7%) or Europe (n = 43; 28.7%) and investigated foods or beverages (n = 60; 40.0%) and cancer morbidity and mortality (n = 54; 36%). Reviews often had important limitations: less than one-quarter (n = 30; 20.0%) reported preregistration of a protocol and almost one-third (n = 42; 28.0%) did not report a replicable search strategy. Suboptimal practices and errors in the synthesis of results were common: one-quarter of meta-analyses (n = 30; 26.1%) selected the meta-analytic model based on statistical indicators of heterogeneity and almost half of meta-analyses (n = 50; 43.5%) did not consider dose-response associations even when it was appropriate to do so. Only 16 (10.7%) reviews used an established system to evaluate the certainty of evidence.

CONCLUSIONS

Systematic reviews of nutritional epidemiology studies often have serious limitations. Authors can improve future reviews by involving statisticians, methodologists, and researchers with substantive knowledge in the specific area of nutrition being studied and using a rigorous and transparent system to evaluate the certainty of evidence.