The application of meta-analytic (multi-level) models with multiple random effects: A systematic review

A Meta-Analytical Way of Systematizing the Use of Hyaluronan Gels for the Relief of Osteoarthritis, Compared with New Treatment Alternatives

Hyaluronic acid, in the form of a gel or viscoelastic colloidal solution, is currently used for the viscosupplementation of joints affected by osteoarthritis, but its effectiveness is under debate in relation to newer alternatives. Based on meta-analytical arguments, the present article reinforces the opinion that there are still no decisive arguments for its complete replacement but for its use adapted to the peculiarities of the disease manifestation and of the patients. A "broad" comparison is first made with almost all alternatives studied in the last decade, and then a meta-regression study is performed to compare and predict the effect size induced by viscosupplementation therapy and its main challenger of clinical interest, the platelet-rich plasma treatment. If they are computerized, the developed models can represent tools for clinicians in determining the appropriateness of the option or not for viscosupplementation in a manner adapted to the pain felt by the patients, to their age, or to other clinical circumstances. The models were generated using algorithms implemented in the R language and assembled in different R packages. All primary data and necessary R scripts are provided in accordance with the philosophy of reproducible research. Finally, we adhere in a documented way to the opinion that HA-based products, currently under circumspection, are still clinically useful.

Effectiveness of primary care interventions in conjointly treating comorbid chronic pain and depression: a systematic review and meta-analysis

BACKGROUND

Chronic pain and depression are highly comorbid, but the lack of consensus on the best treatment strategies puts patients at high risk of suboptimal care-coordination as well as health and social complications. Therefore, this study aims to quantitatively assesses how effective different primary care interventions have been in treating the comorbid state of chronic pain and depression. In particular, this study evaluates both short-term outcomes-based specifically on measures of chronic pain and depression during an intervention itself-and long-term outcomes or measures of pain and depression in the months after conclusion of the formal study intervention.

METHODS

This study is a systematic review and meta-analysis of randomised-controlled trials (RCTs) enrolling patients with concurrent chronic pain and depression. Intensity and severity of pain and depression symptoms were the primary outcomes. The main inclusion criteria were RCTs that: (i) enrolled patients diagnosed with depression and chronic pain, (ii) occurred in primary care settings, (iii) reported baseline and post-intervention outcomes for chronic pain and depression, (iv) lasted at least 8 weeks, and (v) used clinically validated outcome measures. Risk of bias was appraised with the Risk of Bias 2 tool, and GRADE guidelines were used to evaluate the quality of evidence.

RESULTS

Of 692 screened citations, 7 multicomponent primary care interventions tested across 891 patients were included. Meta-analyses revealed significant improvements in depression at post-intervention (SMD = 0.44, 95% CI [0.17, 0.71], P = 0.0014) and follow-up (SMD = 0.41, 95% CI [0.01, 0.81], P = 0.0448). Non-significant effects were observed for chronic pain at post-intervention (SMD = 0.27, 95% CI [-0.08, 0.61], P = 0.1287) and follow-up (SMD = 0.13, 95% CI [-0.3, 0.56], P = 0.5432).

CONCLUSIONS

Based on the results of the meta-analysis, primary care interventions largely yielded small to moderate positive effects for depressive symptoms and no significant effects on pain. In one study, stepped-care to be more effective in treatment of comorbid chronic pain and depression than other interventions both during the intervention and upon post-intervention follow-up. As such, depression appears more amenable to treatment than pain, but the number of published RCTs assessing both conditions is limited. More research is needed to further develop optimal treatment strategies.

The association between quality of therapeutic alliance and treatment outcomes in teletherapy: A systematic review and meta-analysis

OBJECTIVE

The strength of the therapeutic alliance is widely understood to impact treatment outcomes, however, the alliance-outcome relationship in teletherapy has remained relatively unexamined. The aim of this meta-analysis is to systematically summarize the relationship between therapeutic alliance and treatment outcomes in teletherapy with adult patients conducted via videoconferencing or telephone.

METHODS

We conducted a systematic search of the databases PsycINFO, PsycARTICLES, ProQuest Dissertation Databases, EMBASE, The Cochrane Library, MEDLINE, Google Scholar, and PubMed for studies published before June 26, 2023. We identified 31 studies with 34 independent samples (4862 participants).

RESULTS

The average weighted effect size was 0.15, p = .001, 95% CI [0.07, 0.24], k = 34. reflecting a small effect of therapeutic alliance on mental health outcomes. There was significant heterogeneity in the effect sizes, which was driven by between-study differences in the alliance-outcome correlation. The alliance-outcome effect was larger when the alliance was measured late in treatment and when the outcome was measured from the patient's perspective.

CONCLUSION

Very few teletherapy treatment studies were identified that initially reported on alliance-outcome associations, underlining that this is an under-researched area. The association between alliance-teletherapy outcomes in this meta-analysis was small but significant, and somewhat weaker than the alliance-outcome associations reported for in-person treatments and other online interventions. This might indicate that there are other processes at play in teletherapy that explain variance of treatment outcomes, or that the therapist (and the relationship) has less influence on the treatment outcomes than in in-person therapy.

Pathological response to neoadjuvant chemoradiotherapy for oesophageal squamous cell carcinoma in Eastern versus Western countries: meta-analysis

OBJECTIVE

Locally advanced oesophageal squamous cell carcinoma can be treated with neoadjuvant chemoradiotherapy or chemotherapy followed by oesophagectomy. Discrepancies in pathological response rates have been reported between studies from Eastern versus Western countries. The aim of this study was to compare the pathological response to neoadjuvant chemoradiotherapy in Eastern versus Western countries.

METHODS

Databases were searched until November 2022 for studies reporting pCR rates after neoadjuvant chemoradiotherapy for oesophageal squamous cell carcinoma. Multi-level meta-analyses were performed to pool pCR rates separately for cohorts from studies performed in centres in the Sinosphere (East) or in Europe and the Anglosphere (West).

RESULTS

For neoadjuvant chemoradiotherapy, 51 Eastern cohorts (5636 patients) and 20 Western cohorts (3039 patients) were included. Studies from Eastern countries included more men, younger patients, more proximal tumours, and more cT4 and cN+ disease. Patients in the West were more often treated with high-dose radiotherapy, whereas patients in the East were more often treated with a platinum + fluoropyrimidine regimen. The pooled pCR rate after neoadjuvant chemoradiotherapy was 31.7% (95% c.i. 29.5% to 34.1%) in Eastern cohorts versus 40.4% (95% c.i. 35.0% to 45.9%) in Western cohorts (fixed-effect P = 0.003). For cohorts with similar cTNM stages, pooled pCR rates for the East and the West were 32.5% and 41.9% respectively (fixed-effect P = 0.003).

CONCLUSION

The pathological response to neoadjuvant chemoradiotherapy is less favourable in patients treated in Eastern countries compared with Western countries. Despite efforts to investigate accounting factors, the discrepancy in pCR rate cannot be entirely explained by differences in patient, tumour, or treatment characteristics.

Effectiveness of interventions for school-aged-children and adolescents with fetal alcohol spectrum disorder: a systematic review and meta-analysis

PURPOSE

To describe allied health and educational interventions and their effectiveness for children and adolescents with fetal alcohol spectrum disorder (FASD). To appraise the quality and strength of studies.

METHODS

Electronic databases were searched between 2005 and March 2022, identifying non-pharmacological studies supporting function, activity, or participation for FASD participants aged 5-18 years using any quantitative research design. Outcomes were coded using International Classification of Functioning, Disability and Health, family of Participation Related Constructs and behaviour categories. Multi-level random-effects meta-analysis examined intervention effects. Study methodological quality was evaluated using Cochrane risk of bias tools, RoBiNT, AMSTAR 2 and NHMRC Hierarchy levels of evidence. Certainty of findings were synthesised using GRADE approach.

RESULTS

The systematic review included 25 studies with 735 participants, 10 of which were analysed by meta-analysis. Body function and structure, activity, behaviour, and sense of self outcomes were pooled. A small, positive effect favouring interventions was found (g = 0.29, 95% CI = 0.15-0.43), however the GRADE certainty was rated as low. No participation outcomes were identified.

CONCLUSIONS

Some interventions targeting body function and structure, activity and behaviour outcomes were effective. Evidence of interventions that support children's and adolescent's participation as an outcome is lacking.

Time points of outcome are often neglected in acupuncture meta-analyses: a methodological survey

OBJECTIVES

To systematically understand the transparency of outcome measurement time point reporting in meta-analyses of acupuncture.

STUDY DESIGN AND SETTING

We searched for meta-analyses of acupuncture published between 2013 and 2022 in PubMed, Embase, and Cochrane Library. A team of method-trained investigators screened studies for eligibility and collected data using pilot-tested standardized questionnaires. We documented in detail the reporting of outcome measurement time points in acupuncture meta-analyses.

RESULTS

A total of 224 acupuncture meta-analyses were included. Of these, 98 (43.8%) studies did not specify the time points of primary outcome. Among 126 (56.3%) meta-analyses which reported the time points of primary outcome, only 22 (17.5%) meta-analyses specified time points in corresponding protocol. Among 48 (38.1%) meta-analyses that estimated treatment effects of multiple time points, 11 (22.9%) meta-analyses used inappropriate meta-analysis method (subgroup analysis) to pool effect size, and none of the meta-analyses used advanced methods for pooling effect sizes at different time points.

CONCLUSION

Transparency in reporting outcome time points for acupuncture meta-analyses and appropriate methods to pool the effect size of multiple time points were lacking. For future systematic reviews, the transparency of outcome measurement time points should be emphasized in the protocols and final reports. Furthermore, advanced methods should be considered for pooling effect sizes at multiple time points.

Executive functioning in antisocial behavior: A multi-level systematic meta-analysis

Neurobiological information - including executive functioning - is increasingly relevant for forensic clinical practice, as well as for the criminal justice system. Previous meta-analyses report that antisocial populations show impaired performance on executive functioning tasks, but these meta-analyses are outdated, have limitations in their methodological approach, and are therefore in need of an update. The current multi-level meta-analysis including 133 studies (2008-2023) confirms impaired performance in executive functioning (d=.42), but studies are heterogeneous. Several moderator analyses showed that neuropsychological test used, type of executive function component, and control group characteristics moderated the overall effect. Specifically, matching psychiatric problems in the non-antisocial control group eliminated any differences in executive functioning between groups. No moderation effects were found for assessment quality, hot or cold executive functions, and various population characteristics. These results could indicate that the assessment of executive functioning in antisocial populations may be less relevant for recidivism risk assessment than thought, although this should first be assessed in prospective longitudinal studies. Executive functioning could potentially be used to identify or screen for individuals with certain treatment needs or be used as a responsivity factor, especially in disorders which are often underdiagnosed in criminal justice settings.

Virtual Reality Breathing Interventions for Mental Health: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Breathing exercises have been shown to reduce mental health problems among clinical and non-clinical populations. Although virtual reality (VR) breathing interventions are assumed to have potential benefits, it remains unclear whether VR breathing interventions are more effective at improving mental health than non-VR breathing interventions. We conducted a systematic literature search in six electronic databases (Web of Science, PsycINFO, Embase, Cochrane Central Register of Controlled Trials, Scopus, and PubMed) from inception to 30th September, 2022. We included randomized controlled trials in adults evaluating effects of VR compared to non-VR breathing interventions on primary outcomes of mental health (stress, anxiety and mood), and secondary outcomes of physiological stress measures (e.g., heart rate (HR), heart rate variability (HRV)). Within these selected studies, we explored differences in likeability and future use between VR and non-VR breathing interventions. 2.848 records were identified of which 65 full-text articles were assessed. Six RCTs were included, of which five were suitable for meta-analyses. Comparing VR to non-VR breathing interventions, there were no significant differences in overall mental health, stress, anxiety or mood, nor in HR or HRV. There was no evidence that participants liked VR breathing interventions more than non-VR, nor would use them more in the future. These results suggest that there is no evidence that VR breathing interventions are more effective than non-VR in improving mental health outcomes, HR, HRV. Further research is required to determine whether there may be advantages to longer-term VR-implementation and practice, and explore possible mechanisms.

Systematic review of early warning signs of relapse and behavioural antecedents of symptom worsening in people living with schizophrenia spectrum disorders

BACKGROUND

Identification of the early warning signs (EWS) of relapse is key to relapse prevention in schizophrenia spectrum disorders, however, limitations to their precision have been reported. Substantial methodological innovations have recently been applied to the prediction of psychotic relapse and to individual psychotic symptoms. However, there has been no systematic review that has integrated findings across these two related outcomes and no systematic review of EWS of relapse for a decade.

METHOD

We conducted a systematic review of EWS of psychotic relapse and the behavioural antecedents of worsening psychotic symptoms. Traditional EWS and ecological momentary assessment/intervention studies were included. We completed meta-analyses of the pooled sensitivity and specificity of EWS in predicting relapse, and for the prediction of relapse from individual symptoms.

RESULTS

Seventy two studies were identified including 6903 participants. Sleep, mood, and suspiciousness, emerged as predictors of worsening symptoms. Pooled sensitivity and specificity of EWS in predicting psychotic relapse was 71% and 64% (AUC value = 0.72). There was a large pooled-effect size for the model predicting relapse from individual symptom which did not reach statistical significance (d = 0.81, 95%CIs = -0.01, 1.63).

CONCLUSIONS

Important methodological advancements in the prediction of psychotic relapse in schizophrenia spectrum disorders are evident with improvements in the precision of prediction. Further efforts are required to translate these advances into effective clinical innovations.

Spontaneous Trait Inferences From Behavior: A Systematic Meta-Analysis

Research suggests that people spontaneously infer traits from behavioral information, thus forming impressions of actors' personalities. Such spontaneous trait inferences (STI) have been examined in a wide range of studies in the last four decades. Here, we provide the first systematic meta-analysis of this vast literature. We included data from k = 86 publications, with overall N = 13,630 participants. The average STI effect was moderate to large (dz = 0.59) and showed substantial heterogeneity. The type of experimental paradigm significantly moderated the STI effect size, with larger effects in long-term memory-based paradigms compared with working memory-based paradigms. Generally, STI effects were robust to various methodological variations and also to potential concerns of publication bias. Contrary to expectations, cultural background (independent vs. interdependent) did not emerge as a significant moderator of STI effects. We discuss these findings with respect to their theoretical relevance and derive implications for future research and theorizing.

E-learning as a tool of suicide prevention training: A meta-analysis and systematic review

Suicide is a global health challenge. One prevention strategy is teaching individuals how to detect and respond to suicidality. These training have increasingly been delivered online. We searched WoS, Scopus, and PubMed from inception until the 20 September 2023 to evaluate e-learning efficacy as standardized mean changes and standardized mean differences. We synthesized main results using multilevel meta-analyses and subgroups using random-effects meta-analyses. Robins-I, RoB-II and trim-and-fill were used to assess the risk of bias. Of the 6516 initially screened articles, 26 were included. Overall, e-learning increased suicide prevention skills. Subgroups reported differing results: e-learning affected knowledge and self-efficacy more than behavior and attitudes. Efficacy, short duration, and low-cost suggest that e-learning may be feasible in teaching basic suicide prevention skills to lay people. However, current evidence suggests that health care professionals should not rely on e-learning as a training modality, except when no other form of training is available. Preregisteration: CRD42020218978.

Extinction in multiple contexts reduces the return of extinguished responses: A multilevel meta-analysis

Extinguished responses have been shown to reappear under several circumstances, and this reappearance is considered to model behaviors such as relapse after exposure therapy. Conducting extinction in multiple contexts has been explored as a technique to decrease the recovery of extinguished responses. The present meta-analysis aimed to examine whether extinction in multiple contexts can consistently reduce the recovery of extinguished responses. After searching in several databases, experiments were included in the analysis if they presented extinction in multiple contexts, an experimental design, and an adequate statistical report. Cohen's d was obtained for each critical comparison and weighted to obtain the sample's average weighted effect size. Analyses were then performed using a multilevel meta-analytic approach. Twenty-five studies were included, with a total sample of 37 experiments or critical comparisons. The analyses showed a large effect size for the sample, moderated by the length of conditioned stimulus exposure, type of experimental subject, and type of recovery. The robust effect of extinction in multiple contexts on relapse should encourage clinicians to consider extinction in multiple contexts as a useful technique in therapy and research.

Spindle-dependent memory consolidation in healthy adults: A meta-analysis

Accumulating evidence suggests a central role for sleep spindles in the consolidation of new memories. However, no meta-analysis of the association between sleep spindles and memory performance has been conducted so far. Here, we report meta-analytical evidence for spindle-memory associations and investigate how multiple factors, including memory type, spindle type, spindle characteristics, and EEG topography affect this relationship. The literature search yielded 53 studies reporting 1427 effect sizes, resulting in a small to moderate effect for the average association. We further found that spindle-memory associations were significantly stronger for procedural memory than for declarative memory. Neither spindle types nor EEG scalp topography had an impact on the strength of the spindle-memory relation, but we observed a distinct functional role of global and fast sleep spindles, especially for procedural memory. We also found a moderation effect of spindle characteristics, with power showing the largest effect sizes. Collectively, our findings suggest that sleep spindles are involved in learning, thereby representing a general physiological mechanism for memory consolidation.

Estimating reliabilities and correcting for sampling error in indices of within-person dynamics derived from intensive longitudinal data

Psychology has witnessed a dramatic increase in the use of intensive longitudinal data (ILD) to study within-person processes, accompanied by a growing number of indices used to capture individual differences in within-person dynamics (WPD). The reliability of WPD indices is rarely investigated and reported in empirical studies. Unreliability in these indices can bias parameter estimates and yield erroneous conclusions. We propose an approach to (a) estimate the reliability and (b) correct for sampling error of WPD indices using "Level-1 variance-known" (V-known) multilevel models (Raudenbush & Bryk, 2002). When WPD indices are calculated for each individual, the sampling variance of the observed WPD scores is typically falsely assumed to be zero. V-known models replace this "zero" with an approximate sampling variance fixed at Level 1 to estimate the true variance of the index at Level 2, following random effects meta-analysis principles. We demonstrate how V-known models can be applied to a broad range of emotion dynamics commonly derived from ILD, including indices of the average level (mean), variability (intraindividual standard deviation), instability (probability of acute change), bipolarity (correlation), differentiation (intraclass correlation), inertia (autocorrelation), and relative variability (relative standard deviation) of emotions. A simulation study shows the usefulness of V-known models to recover the true reliability of these indices. Using a 21-day diary study, we illustrate the implementation of the proposed approach to obtain reliability estimates and to correct for unreliability of WPD indices in real data. The techniques may facilitate psychometrically sound inferences from WPD indices in this burgeoning research area.

Change in neurodevelopmental outcomes for extremely premature infants over time: a systematic review and meta-analysis

OBJECTIVE

Survival rates of extremely premature infants are rising, but changes in neurodevelopmental impairment (NDI) rates are unclear. Our objective was to perform a systematic review of intrainstitutional variability of NDI over time.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Ovid MEDLINE, Embase, PubMed, Cochrane Library and Google Scholar.

STUDY SELECTION

Study eligibility: (1) at least two discrete cohorts of infants born <27 weeks' gestation or <1000 g birth weight, (2) one cohort born after 1990 and at least one subsequent cohort of similar gestational age, (3) all cohorts cared for within the same Neonatal Intensive Care Unit(s) (NICU) and (4) neurodevelopmental outcomes at 18-36 months corrected age.

MAIN OUTCOME

Change in NDI rates. Quality, validity and bias were assessed using Grading of Recommendations, Assessment, Development, and Evaluation and Quality in Prognosis Studies guidelines.

RESULTS

Of 203 publications, 15 were eligible, including 13 229 infants. At the first time point, average NDI rate across study groups weighted by sample size was 41.0% (95% CI 34.0% to 48.0%). The average change in NDI between time points was -3.3% (95% CI -8·8% to 2.2%). For each added week of gestation at birth, the rate of NDI declined by 9.7% (95% CI 6.2% to 13.3%). Most studies exhibited moderate-severe bias in at least one domain, especially attrition rates.

CONCLUSIONS

When comparing discrete same-centre cohorts over time, there was no significant change in NDI rates in infants born <27 weeks' gestation or <1000 g. Higher survival rates unaccompanied by improvement in neurodevelopment highlight urgency for renewed focus on the causes of NDI and evidence-based strategies to reduce brain injury.

Treatment of childhood disruptive behavior disorders and callous-unemotional traits: a systematic review and two multilevel meta-analyses

BACKGROUND

Children with callous-unemotional (CU) traits are at high lifetime risk of antisocial behavior. It is unknown if treatments for disruptive behavior disorders are as effective for children with CU traits (DBD+CU) as those without (DBD-only), nor if treatments directly reduce CU traits. Separate multilevel meta-analyses were conducted to compare treatment effects on DBD symptoms for DBD+CU versus DBD-only children and evaluate direct treatment-related reductions in CU traits, as well as to examine moderating factors for both questions.

METHODS

We systematically searched PsycINFO, PubMed, Cochran Library (Trials), EMBASE, MEDLINE, APA PsycNet, Scopus, and Web of Science. Eligible studies were randomized controlled trials, controlled trials, and uncontrolled studies evaluating child-focused, parenting-focused, pharmacological, family-focused, or multimodal treatments.

RESULTS

Sixty studies with 9,405 participants were included (Mage  = 10.04, SDage  = 3.89 years, 25.09% female, 44.10% racial/ethnic minority). First, treatment was associated with similar reductions in DBD symptoms for DBD+CU (SMD = 1.08, 95% CI = 0.45, 1.72) and DBD-only (SMD = 1.01, 95% CI = 0.38, 1.64). However, DBD+CU started (SMD = 1.18, 95% CI = 0.57, 1.80) and ended (SMD = 0.73, p < .001; 95% CI = 0.43, 1.04) treatment with more DBD symptoms. Second, although there was no overall direct effect of treatment on CU traits (SMD = .09, 95% CI = -0.02, 0.20), there were moderating factors. Significant treatment-related reductions in CU traits were found for studies testing parenting-focused components (SMD = 0.21, 95% CI = 0.06, 0.35), using parent-reported measures (SMD = 0.16, 95% CI = 0.04, 0.28), rated as higher quality (SMD = 0.26, 95% CI = 0.13, 0.39), conducted outside the United States (SMD = 0.19, 95% CI = 0.05, 0.32), and with less than half the sample from a racial/ethnic minority group (SMD = 0.15, 95% CI = 0.002, 0.30).

CONCLUSIONS

DBD+CU children improve with treatment, but their greater DBD symptom severity requires specialized treatment modules that could be implemented alongside parenting programs. Conclusions are tempered by heterogeneity across studies and scant evidence from randomized controlled trials.

The effectiveness of social network interventions for psychiatric patients: A systematic review and meta-analysis

Strengthening social networks is an important goal in mental health treatment. This study aimed to determine the effectiveness of social network interventions for psychiatric patients. A systematic review and meta-analysis was conducted comparing these interventions with control groups on social and mental health-related outcomes in psychiatric patients. PubMed, EMBASE.com, PsycInfo, Scopus, and IBSS were searched for studies until December 21, 2022. Three-level random effects models were used to obtain Cohen's d mean estimates on composite outcomes of social network and secondary mental health outcomes. Heterogeneity was examined with potential moderators. Thirty-three studies were included. Small-to-moderate effects of social network interventions were detected on positive social network (d = 0.115, p = 0.022) and support (d = 0.159; p = 0.007), general functioning (d = 0.127, p = 0.046), mental health treatment adherence (d = 0.332, p = 0.003), days substance use (d = 0.097, p = 0.004), and abstinence (d = 0.254, p = 0.004). Estimates of psychiatric functioning were higher in samples with more females. The quality of evidence was moderate-to-low. This evidence suggests that social network interventions can improve positive social networks, general functioning, mental health treatment adherence, and substance use in psychiatric patients receiving usual care. PROSPERO ID: CRD42019131959.

Risk and protective factors for stress generation: A meta-analytic review

The stress generation hypothesis suggests that some individuals contribute more than others to the occurrence of dependent (self-generated), but not independent (fateful), stressful life events. This phenomenon is commonly studied in relation to psychiatric disorders, but effects are also driven by underlying psychological processes that extend beyond the boundaries of DSM-defined entities. This meta-analytic review of modifiable risk and protective factors for stress generation synthesizes findings from 70 studies with 39,693 participants (483 total effect sizes) from over 30 years of research. Findings revealed a range of risk factors that prospectively predict dependent stress with small-to-moderate meta-analytic effects (rs = 0.10-0.26). Negligible to small effects were found for independent stress (rs = 0.03-0.12), and, in a critical test for stress generation, most effects were significantly stronger for dependent compared to independent stress (βs = 0.04-0.15). Moderation analyses suggest effects of maladaptive interpersonal emotion regulation behaviors and repetitive negative thinking are stronger for interpersonal (versus non-interpersonal) stress; effects of repetitive negative thinking and excessive standards for self may be inflated by overreliance on self-report measures that fail to isolate psychological distress from objective experience. Findings have key implications for advancing stress generation theory and informing targets for intervention.

Network meta-analysis in psychology and educational sciences: A systematic review of their characteristics

Network meta-analysis (NMA) allows the combination of evidence on the effectiveness of several interventions. NMA has mainly been applied in the medical science field, whereas in the domain of psychology and educational sciences its use is less frequent. Consequently, systematic reviews that describe the characteristics of published NMAs are limited to the field of medicine, and nothing is known about the characteristics of NMAs published in the psychology and educational sciences field. However, this information is still relevant for the design of future simulation studies and for detecting good and bad research practices. Thus, this study describes the features of the meta-analytic datasets of NMAs published in the field of psychology and educational sciences, as well as their methodological characteristics, and compares them to those observed in the medical domain. Results show that the number of studies included is larger in NMAs from psychology and educational sciences, the most commonly used effect size is the standardized mean difference (unlike the odds ratio in medicine), the sample size is smaller, more intervention groups are included, and inconsistent effects are observed more often. These results can be used in future simulation studies to generate realistic datasets. Finally, we warn about the poor quality of reporting of some technical aspects of the NMA, such as the statistical model used.

Victims of Child Abuse Dropping Out of Trauma-Focused Treatment: A Meta-Analysis of Risk Factors

A substantial number of children who experienced child maltreatment drop out of evidence-based trauma-focused treatments (TF-CBT). Identifying child, family, and treatment-related factors associated with treatment dropout is important to be able to prevent this from happening and to effectively treat children's trauma-related symptoms. Methods: A quantitative review was performed based on a systematic synthesis of the literature on potential risk factors for dropout of trauma-focused treatment in maltreated children. Results: Eight studies were included, that examined TF-CBT, reporting on 139 effects of potential risk factors for dropout. Each factor was classified into one of ten domains. Small but significant effects were found for the "Demographic and Family" risk domain (r = .121), with factors including being male, child protective services involvement or placement, and minority status, and for the "Youth Alliance" risk domain (r = .207), with factors including low therapist-child support and low youth perception of parental approval. Moderator analyses suggested that family income and parental education may better predict the risk for TF-CBT dropout than other variables in the "Demographic and Family" domain. Conclusions: Our results provide a first overview of risk factors for dropout of trauma-focused treatments (TF-CBT) after child maltreatment, and highlight the role of the therapeutic relationship in this.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40653-022-00500-2.

Psychopathic Traits and Theory of Mind Task Performance: A Systematic Review and Meta-analysis

This meta-analysis aims to examine the relationship between psychopathic traits and theory of mind (ToM), which is classically and broadly defined as competency in representing and attributing mental states such as emotions, intentions, and beliefs to others. Our search strategy gathered 142 effect sizes, from 42 studies, with a total sample size of 7463 participants. Random effects models were used to analyze the data. Our findings suggested that psychopathic traits are associated with impaired ToM task performance. This relationship was not moderated by age, population, psychopathy measurement (self-report versus clinical checklist) or conceptualization, or ToM task type (cognitive versus affective). The effect also remained significant after excluding tasks that did not require the participant to 1) mentalize or 2) differentiate self and other perspectives. However, interpersonal/affective traits were associated with a more pronounced impairment in ToM task performance compared to lifestyle/antisocial traits. Future research should investigate the effects of distinct psychopathy facets that will allow for a more precise understanding of the social-cognitive bases of relevant clinical presentations in psychopathy.

The association between working memory and mathematical problem solving: A three-level meta-analysis

Although working memory (WM) is an important factor in mathematical problem solving (MPS), it remains unclear how well WM relates to MPS. Thus, we aimed to determine this relationship by using a meta-analysis. We searched electronic databases for studies published between 2000 and 2020 and established operational criteria. We conducted Egger’s regression tests and created funnel plots to test for publication bias. Finally, a three-level meta-analytic model analysis of data from 130 studies involving 43,938 participants and 1,355 effect sizes revealed a moderate relationship between WM and MPS (r = 0.280, 95% CI = [0.263, 0.314]). Moreover, moderator analyses showed that: (1) dressed-up word problems were more strongly tied to WM than to intra-mathematical problems; (2) the central executive function showed the strongest relation with MPS, whereas the phonological loop had the weakest; (3) gender ratio had significant moderating effects; and (4) some of the above-mentioned significant moderating effects were unique after controlling for other factors. Implications for research and practice were also discussed.

Hazard characterization of bisphenol A (BPA) based on rodent models - Multilevel meta-analysis and dose-response analysis for reproductive toxicity

Bisphenol A (BPA) is a widely used synthetic industrial compound frequently detected in food. Dietary exposure to BPA has been recognised as a potential health concern. However, there are uncertainties regarding BPA toxicity. The primary objective of this study was to summarise and analyse multiple toxicity endpoints of adverse reproductive effects caused by BPA exposure in rodent models. Therefore, a multilevel meta-analysis and subsequent dose-response analysis were conducted. Relevant articles published in English between 2012 and 2021 were collected from online databases, viz. Scopus, EmBase, Web of Science, and PubMed. In total, 41 studies were included for statistical analysis. All statistical analyses were performed using open-source RStudio packages. Summary effects indicated the statistical significance of BPA exposure on decreased sperm concentration (Hedges' g: -1.35) and motility (Hedges' g: -1.12) on average, while no significant effects were observed on the absolute and relative weight of male and female reproductive organs. The lowest mean toxicological reference dose values of 0.0011 mg (kg bw)^-1 day^-1 was proposed for BPA exposure on sperm concentration from the dose-response model. In conclusion, potential health risks from BPA exposure were shown with regards to reproductive toxicity, especially that sperm concentration and sperm motility require further attention.

Survey mode and nonresponse bias: A meta-analysis based on the data from the international social survey programme waves 1996-2018 and the European social survey rounds 1 to 9

The constant increase in survey nonresponse and fieldwork costs are the reality of survey research. Together with other unpredictable events occurring in the world today, this increase poses a challenge: the necessity to accelerate a switch from face-to-face data collection to different modes, that have usually been considered to result in lower response rates. However, recent research has established that the simple response rate is a feeble measure of study quality. Therefore, this article aims to analyze the effect of survey characteristics, especially the survey mode, on the nonresponse bias. The bias measure used is the internal criteria first proposed by Sodeur and first applied by Kohler. The analysis is based on the survey documentation and results from the International Social Survey Programme waves 1996-2018 and the European Social Survey rounds 1 to 9. Random-effects three-level meta-regression models, based on data from countries from each inhabited continent, were created in order to estimate the impact of the survey mode or modes, sampling design, fieldwork experience, year of data collection, and response rate on the nonresponse bias indicator. Several ways of nesting observations within clusters were also proposed. The results suggest that using mail and some types of mixed-mode surveys were connected to lower nonresponse bias than using face-to-face mode surveys.

A systematic review and Bayesian meta-analysis of the acoustic features of infant-directed speech

When speaking to infants, adults often produce speech that differs systematically from that directed to other adults. To quantify the acoustic properties of this speech style across a wide variety of languages and cultures, we extracted results from empirical studies on the acoustic features of infant-directed speech. We analysed data from 88 unique studies (734 effect sizes) on the following five acoustic parameters that have been systematically examined in the literature: fundamental frequency (f₀), f₀ variability, vowel space area, articulation rate and vowel duration. Moderator analyses were conducted in hierarchical Bayesian robust regression models to examine how these features change with infant age and differ across languages, experimental tasks and recording environments. The moderator analyses indicated that f₀, articulation rate and vowel duration became more similar to adult-directed speech over time, whereas f₀ variability and vowel space area exhibited stability throughout development. These results point the way for future research to disentangle different accounts of the functions and learnability of infant-directed speech by conducting theory-driven comparisons among different languages and using computational models to formulate testable predictions.

Neuromodulatory effects of transcranial magnetic stimulation on language performance in healthy participants: Systematic review and meta-analysis

Background

The causal relationships between neural substrates and human language have been investigated by transcranial magnetic stimulation (TMS). However, the robustness of TMS neuromodulatory effects is still largely unspecified. This study aims to systematically examine the efficacy of TMS on healthy participants' language performance.

Methods

For this meta-analysis, we searched PubMed, Web of Science, PsycINFO, Scopus, and Google Scholar from database inception until October 15, 2022 for eligible TMS studies on language comprehension and production in healthy adults published in English. The quality of the included studies was assessed with the Cochrane risk of bias tool. Potential publication biases were assessed by funnel plots and the Egger Test. We conducted overall as well as moderator meta-analyses. Effect sizes were estimated using Hedges'g (g) and entered into a three-level random effects model.

Results

Thirty-seven studies (797 participants) with 77 effect sizes were included. The three-level random effects model revealed significant overall TMS effects on language performance in healthy participants (RT: g = 0.16, 95% CI: 0.04-0.29; ACC: g = 0.14, 95% CI: 0.04-0.24). Further moderator analyses indicated that (a) for language tasks, TMS induced significant neuromodulatory effects on semantic and phonological tasks, but didn't show significance for syntactic tasks; (b) for cortical targets, TMS effects were not significant in left frontal, temporal or parietal regions, but were marginally significant in the inferior frontal gyrus in a finer-scale analysis; (c) for stimulation parameters, stimulation sites extracted from previous studies, rTMS, and intensities calibrated to the individual resting motor threshold are more prone to induce robust TMS effects. As for stimulation frequencies and timing, both high and low frequencies, online and offline stimulation elicited significant effects; (d) for experimental designs, studies adopting sham TMS or no TMS as the control condition and within-subject design obtained more significant effects.

Discussion

Overall, the results show that TMS may robustly modulate healthy adults' language performance and scrutinize the brain-and-language relation in a profound fashion. However, due to limited sample size and constraints in the current meta-analysis approach, analyses at a more comprehensive level were not conducted and results need to be confirmed by future studies.

Systematic review registration

[https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=366481], identifier [CRD42022366481].

Auditory brainstem response deficits in learning disorders and developmental language disorder: a systematic review and meta-analysis

Although learning disorders (LD) and developmental language disorder (DLD) can be linked to overlapping psychological and behavioral deficits, such as phonological, morphological, orthographic, semantic, and syntactic deficits, as well as academic (e.g., reading) difficulties, they are currently separate diagnoses in the DSM-5 with explicit phenotypic differences. At a neural level, it is yet to be determined to what extent they have overlapping or distinct signatures. The identification of such neural markers/endophenotypes could be important for the development of physiological diagnostic tools, as well as an understanding of disorders across different dimensions, as recommended by the Research Domain Criteria Initiative (RDoC). The current systematic review and meta-analysis examined whether the two disorders can be differentiated based on the auditory brainstem response (ABR). Even though both diagnoses require hearing problems to be ruled out, a number of articles have demonstrated associations of these disorders with the auditory brainstem response. We demonstrated that both LD and DLD are associated with longer latencies in ABR Waves III, V, and A, as well as reduced amplitude in Waves V and A. However, multilevel subgroup analyses revealed that LD and DLD do not significantly differ for any of these ABR waves. Results suggest that less efficient early auditory processing is a shared mechanism underlying both LD and DLD.

Mindfulness-Oriented Recovery Enhancement for Addictive Behavior, Psychiatric Distress, and Chronic Pain: A Multilevel Meta-Analysis of Randomized Controlled Trials

Objectives

Methods

Results

Conclusions

Meta-analysis Pre-registration: PROSPERO #CRD42022319006

Supplementary Information

Cross-linguistic influence in simultaneous and early sequential bilingual children: a meta-analysis

Although cross-linguistic influence at the level of morphosyntax is one of the most intensively studied topics in child bilingualism, the circumstances under which it occurs remain unclear. In this meta-analysis, we measured the effect size of cross-linguistic influence and systematically assessed its predictors in 750 simultaneous and early sequential bilingual children in 17 unique language combinations across 26 experimental studies. We found a significant small to moderate average effect size of cross-linguistic influence, indicating that cross-linguistic influence is part and parcel of bilingual development. Language dominance, operationalized as societal language, was a significant predictor of cross-linguistic influence, whereas surface overlap, language domain and age were not. Perhaps an even more important finding was that definitions and operationalisations of cross-linguistic influence and its predictors varied considerably between studies. This could explain the absence of a comprehensive theory in the field. To solve this issue, we argue for a more uniform method of studying cross-linguistic influence.

Research Review: The effect of school-based suicide prevention on suicidal ideation and suicide attempts and the role of intervention and contextual factors among adolescents: a meta-analysis and meta-regression

BACKGROUND

Globally, suicide is the fourth highest cause of adolescent mortality (Suicide: https://www.who.int/news-room/fact-sheets/detail/suicide). The effects of post-primary school-based suicide prevention (PSSP) on adolescent suicidal thoughts and behaviours (STBs) have not been comprehensively synthesised. We aim to estimate the population effect for PSSP interventions on adolescent STBs and explore how intervention effects vary based on intervention and contextual moderators.

METHODS

Searches of PsycINFO, Medline, Education Source, ERIC, Web of Science, and the Cochrane Central Register of Controlled Trials identified cluster randomised trials examining the effectiveness of PSSP on adolescent STBs. The Cochrane Risk of Bias tool assessed bias. Crude and adjusted back-transformed odds ratios (ORs) were calculated. Multilevel random-effects models accounted for dependencies of effects. Univariate meta-regression explored variability of intervention and contextual moderators on pooled effects.

RESULTS

There were 19 and 12 effects for suicidal ideation (SI) and suicide attempts (SA). Compared with controls, interventions were associated with 13% (OR = 0.87, 95%CI [0.78, 0.96]) and 34% (OR = 0.66, 95%CI [0.47, 0.91]) lower crude odds reductions for SI and SA, respectively. Effects were similar for adjusted SI (OR = 0.85, 95%CI [0.75, 0.95]) and SA (OR = 0.72, 95%CI [0.59, 0.87]) models. Within-study (0.20-9.10%) and between-study (0-51.20%) heterogeneity ranged for crude and adjusted SA models and SI heterogeneity was 0%. Moderator analyses did not vary SA effects (ps > .05).

CONCLUSIONS

This meta-analysis contributes to the PSSP evidence-base by demonstrating that PSSP targeting STBs as both primary intervention outcomes and with other health and well-being outcomes reduced SI and SA among 33,155 adolescents attending 329 schools, compared to controls. The number needed to treat estimates suggests the potential of reducing the incidence of SA and SI in one adolescent by implementing PSSP in 1-2 classrooms, supporting PSSP as a clinically relevant suicide prevention strategy. Although moderator analyses were nonsignificant and contained a small number of trials, larger SA effect sizes support particular effectiveness for interventions of a duration of ≤1 week, involving multiple stakeholders and with a 12-month follow-up.

The energetic costs of sub-lethal helminth parasites in mammals: a meta-analysis

Parasites, by definition, have a negative effect on their host. However, in wild mammal health and conservation research, sub-lethal infections are commonly assumed to have negligible health effects unless parasites are present in overwhelming numbers. Here, we propose a definition for host health in mammals that includes sub-lethal effects of parasites on the host's capacity to adapt to the environment and maintain homeostasis. We synthesized the growing number of studies on helminth parasites in mammals to assess evidence for the relative magnitude of sub-lethal effects of infection across mammal taxa based on this expanded definition. Specifically, we develop and apply a framework for organizing disparate metrics of parasite effects on host health and body condition according to their impact on an animal's energetic condition, defined as the energetic burden of pathogens on host physiological and behavioural functions that relate directly to fitness. Applying this framework within a global meta-analysis of helminth parasites in wild, laboratory and domestic mammal hosts produced 142 peer-reviewed studies documenting 599 infection-condition effects. Analysing these data within a multiple working hypotheses framework allowed us to evaluate the relative weighted contribution of methodological (study design, sampling protocol, parasite quantification methods) and biological (phylogenetic relationships and host/parasite life history) moderators to variation in the magnitude of health effects. We found consistently strong negative effects of infection on host energetic condition across taxonomic groups, with unusually low heterogeneity in effect sizes when compared with other ecological meta-analyses. Observed effect size was significantly lower within cross-sectional studies (i.e. observational studies that investigated a sub-set of a population at a single point in time), the most prevalent methodology. Furthermore, opportunistic sampling led to a weaker negative effect compared to proactive sampling. In the model of host taxonomic group, the effect of infection on energetic condition in carnivores was not significant. However, when sampling method was included, it explained substantial inter-study variance; proactive sampling showing a strongly significant negative effect while opportunistic sampling detected only a weak, non-significant effect. This may partly underlie previous assumptions that sub-lethal parasites do not have significant effects on host health. We recommend future studies adopt energetic condition as the framework for assessing parasite effects on wildlife health and provide guidelines for the selection of research protocols, health proxies, and relating infection to fitness.

More focal, less heterogeneous? Multi-level meta-analysis of cathodal high-definition transcranial direct current stimulation effects on language and cognition

High-definition transcranial direct current stimulation (HD-tDCS) is a relatively focal, novel non-invasive brain stimulation method with the potential to investigate the causal contributions of specific cortical brain regions to language and cognition. Studies with HD-tDCS typically employ a 4 × 1 electrode design with a single central target electrode surrounded by four return electrodes, among which return current intensity is evenly distributed. With cathodal HD-tDCS, neural excitability in the target region is assumed to be reduced, which offers interesting perspectives for neuropsychological research and interventions. This multi-level meta-analysis compiles published studies using cathodal HD-tDCS in 4 × 1 configuration to modulate cognition and behavior. Regarding HD-tDCS, 77 effect sizes were gathered from 11 eligible reports. We extended this database with 52 effect sizes from 11 comparable reports using conventional tDCS with cathodal polarity. We observed no significant overall effect and no moderation by within-study and between-study variables in HD. In the extended analysis, results suggested a non-linear moderation of cathodal tDCS effects by intensity, driven by negative effect sizes at 1.5 mA. However, studies varied tremendously in task parameters, outcomes, and even technical parameters. Interestingly, within-study heterogeneity exceeded between-study heterogeneity in the present sample, and moderators hardly reduced the residual heterogeneity. Across domains and configurations, both positive and negative effect sizes are possible. We discuss the findings in relation to conventional cathodal tDCS and the framework of polarity specificity. Fundamental aspects of cathodal HD-tDCS are still to be addressed in future research.

A systematic review and Bayesian meta-analysis of the development of turn taking in adult-child vocal interactions

Fluent conversation requires temporal organization between conversational exchanges. By performing a systematic review and Bayesian multi-level meta-analysis, we map the trajectory of infants' turn-taking abilities over the course of early development (0 to 70 months). We synthesize the evidence from 26 studies (78 estimates from 429 unique infants, of which at least 152 are female) reporting response latencies in infant-adult dyadic interactions. The data were collected between 1975 and 2019, exclusively in North America and Europe. Infants took on average circa 1 s to respond, and the evidence of changes in response over time was inconclusive. Infants' response latencies are related to those of their adult conversational partners: an increase of 1 s in adult response latency (e.g., 400 to 1400 ms) would be related to an increase of over 1 s in infant response latency (from 600 to 1857 ms). These results highlight the dynamic reciprocity involved in the temporal organization of turn-taking. Based on these results, we provide recommendations for future avenues of enquiry: studies should analyze how turn-by-turn exchanges develop on a longitudinal timescale, with rich assessment of infants' linguistic and social development.

Speech-in-noise perception in musicians and non-musicians: A multi-level meta-analysis

Speech-in-noise perception, the ability to hear a relevant voice within a noisy background, is important for successful communication. Musicians have been reported to perform better than non-musicians on speech-in-noise tasks. This meta-analysis uses a multi-level design to assess the claim that musicians have superior speech-in-noise abilities compared to non-musicians. Across 31 studies and 62 effect sizes, the overall effect of musician status on speech-in-noise ability is significant, with a moderate effect size (g = 0.58), 95% CI [0.42, 0.74]. The overall effect of musician status was not moderated by within-study IQ equivalence, target stimulus, target contextual information, type of background noise, or age. We conclude that musicians show superior speech-in-noise abilities compared to non-musicians, not modified by age, IQ, or speech task parameters. These effects may reflect changes due to music training or predisposed auditory advantages that encourage musicianship.

Animal Board Invited Review: Meta-analysis of genetic parameters for resilience and efficiency traits in goats and sheep

Genetic selection focused purely on production traits has proven very successful in improving the productive performance of livestock. However, heightened environmental and infectious disease challenges have raised the need to also improve the resilience of animals to such external stressors, as well as their efficiency in utilising available resources. A better understanding of the relationship between efficiency and production and health traits is needed to properly account for it in breeding programmes and to produce animals that can maintain high production performance in a range of environmental conditions with minimal environmental footprint. The aim of this study was to perform a meta-analysis of genetic parameters for production, efficiency and health traits in sheep and goats. The dataset comprised 963 estimates of heritability and 572 genetic correlations collated from 162 published studies. A threelevel meta-analysis model was fitted. Pooled heritability estimates for milk production traits ranged between 0.27 ± 0.03 and 0.48 ± 0.13 in dairy goats and between 0.21 ± 0.06 and 0.33 ± 0.07 in dairy sheep. In meat sheep, the heritability of efficiency traits ranged from 0.09 ± 0.02 (prolificacy) up to 0.32 ± 0.14 (residual feed intake). For health traits, pooled heritability was 0.07 ± 0.01 (faecal egg count) and 0.21 ± 0.01 (somatic cell score) in dairy goats and 0.14 ± 0.04 (faecal egg count) and 0.13 ± 0.02 (somatic cell score) in dairy sheep. In meat sheep, the heritability of disease resistance and survival traits ranged between 0.07 ± 0.02 (mastitis) and 0.50 ± 0.10 (breech strike). Pooled estimates of genetic correlations between resilience and efficiency traits in dairy goats were not significantly different from zero with the exception of somatic cell score and fat content (-0.19 ± 0.01). In dairy sheep, only the unfavourable genetic correlation between somatic cell score and protein content (0.12 ± 0.03) was statistically significant. In meat sheep only, the correlations between growth and faecal egg count (-0.28 ± 0.11) as well as between growth and dagginess (-0.33 ± 0.13) were statistically significant and favourable. Results of this meta-analysis provide evidence of genetic antagonism between production and health in dairy sheep and goats. This was not observed in meat sheep where most of the pooled estimates had high standard errors and were non-significant. Based on the obtained results, it seems feasible to simultaneously improve efficiency and health in addition to production by including the different types of traits in the breeding goal. However, a better understanding of potential trade-offs between these traits would be beneficial. Particularly, more studies focused on reproduction and resilience traits linked to the animal's multi-trait response to challenges are required.

Extracellular Buffering Supplements to Improve Exercise Capacity and Performance: A Comprehensive Systematic Review and Meta-analysis

BACKGROUND

Extracellular buffering supplements [sodium bicarbonate (SB), sodium citrate (SC), sodium/calcium lactate (SL/CL)] are ergogenic supplements, although questions remain about factors which may modify their effect.

OBJECTIVE

To quantify the main effect of extracellular buffering agents on exercise outcomes, and to investigate the influence of potential moderators on this effect using a systematic review and meta-analytic approach.

METHODS

This study was designed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Three databases were searched for articles that were screened according to inclusion/exclusion criteria. Bayesian hierarchical meta-analysis and meta-regression models were used to investigate pooled effects of supplementation and moderating effects of a range of factors on exercise and biomarker responses.

RESULTS

189 articles with 2019 participants were included, 158 involving SB supplementation, 30 with SC, and seven with CL/SL; four studies provided a combination of buffering supplements together. Supplementation led to a mean estimated increase in blood bicarbonate of + 5.2 mmol L^-1 (95% credible interval (CrI) 4.7-5.7). The meta-analysis models identified a positive overall effect of supplementation on exercise capacity and performance compared to placebo [ES_0.5 = 0.17 (95% CrI 0.12-0.21)] with potential moderating effects of exercise type and duration, training status and when the exercise test was performed following prior exercise. The greatest ergogenic effects were shown for exercise durations of 0.5-10 min [ES_0.5 = 0.18 (0.13-0.24)] and > 10 min [ES_0.5 = 0.22 (0.10-0.33)]. Evidence of greater effects on exercise were obtained when blood bicarbonate increases were medium (4-6 mmol L^-1) and large (> 6 mmol L^-1) compared with small (≤ 4 mmol L^-1) [β_Small:Medium = 0.16 (95% CrI 0.02-0.32), β_Small:Large = 0.13 (95% CrI - 0.03 to 0.29)]. SB (192 outcomes) was more effective for performance compared to SC (39 outcomes) [β_SC:SB = 0.10 (95% CrI - 0.02 to 0.22)].

CONCLUSIONS

Extracellular buffering supplements generate large increases in blood bicarbonate concentration leading to positive overall effects on exercise, with sodium bicarbonate being most effective. Evidence for several group-level moderating factors were identified. These data can guide an athlete's decision as to whether supplementation with buffering agents might be beneficial for their specific aims.

The Relationship between the Chief Executive Officer's (CEO) Social Capital and Dynamic Capabilities: A Meta-Analysis of its Moderators

CEO social capital has shown a positive association with dynamic capabilities, although correlations have considerable heterogeneity among them. This meta-analysis estimates the correlation between CEO social capital and dynamic capabilities, and analyses moderator variables in explaining the heterogeneity in the results. Moderators are classified across four levels from macro to micro variables: country variables, firm environment, firm characteristics, and CEO variables. We apply a systematic search for studies in the Web of Science, Scopus, EBSCO, ProQuest, and Google Scholar databases. Additionally, we used a three-level random-effect meta-analysis on 89 correlations published between 2008 and 2021 from 9,272 CEOs. Findings indicate a positive correlation between CEO social capital and dynamic capabilities. Furthermore, we identified a moderator effect in the country and firm environment level. We found that the country of the study, the perception of transparency and legality in the country, and the environmental dynamism in the market moderate the size of the correlations. We also reject other moderators, including the individualism-collectivism national culture, firm size, the sources of social capital (business or political ties), and the dimension of the social capital (structural, relational or cognitive). This study contributes to the exploration of the sources of dynamic capabilities from the micro-foundation, identifies moderator variables that explain the heterogeneity in the results, and highlights the social nature of management activities which always evolve in a social context.

Modern Meta-Analytic Methods in Prevention Science: Introduction to the Special Issue

Meta-analyses that statistically synthesize evidence from multiple research studies can play an important role in advancing evidence-informed prevention science. When done in the context of a well-conducted systematic review, meta-analysis is a powerful tool for synthesizing evidence and exploring research questions that are difficult to address in individual studies, such as the association of individual study limitations on intervention effect estimates, replicability of empirical findings, and variation of effect estimates across populations and settings. Alongside the rapid growth in the number of published reviews and meta-analyses, there has been a parallel growth in the development of meta-analytic techniques to handle the increasingly complex types of questions and types of evidence relevant to prevention science. Despite this rapid evolution of meta-analytic techniques and approaches, there is still a lag between the development of new techniques and their uptake by researchers in the field. This paper serves as a brief introduction to this special issue of Prevention Science, entitled "Modern Meta-Analytic Methods in Prevention Science," which highlights recent developments in meta-analytic methods and demonstrates their application to prevention research. This special issue makes an important contribution to the field by ensuring these methodological advances are widely accessible to prevention science researchers, thereby improving their uptake and utilization, and ultimately improving the utility and rigor of research syntheses for informing evidence-based decision making in prevention.

Behavioral and Neuroimaging Research on Developmental Coordination Disorder (DCD): A Combined Systematic Review and Meta-Analysis of Recent Findings

AIM

The neurocognitive basis of Developmental Coordination Disorder (DCD; or motor clumsiness) remains an issue of continued debate. This combined systematic review and meta-analysis provides a synthesis of recent experimental studies on the motor control, cognitive, and neural underpinnings of DCD.

METHODS

The review included all published work conducted since September 2016 and up to April 2021. One-hundred papers with a DCD-Control comparison were included, with 1,374 effect sizes entered into a multi-level meta-analysis.

RESULTS

The most profound deficits were shown in: voluntary gaze control during movement; cognitive-motor integration; practice-/context-dependent motor learning; internal modeling; more variable movement kinematics/kinetics; larger safety margins when locomoting, and atypical neural structure and function across sensori-motor and prefrontal regions.

INTERPRETATION

Taken together, these results on DCD suggest fundamental deficits in visual-motor mapping and cognitive-motor integration, and abnormal maturation of motor networks, but also areas of pragmatic compensation for motor control deficits. Implications for current theory, future research, and evidence-based practice are discussed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier: CRD42020185444.

The effectiveness of serious games in improving memory among the elderly with cognitive impairment: A systematic review and meta-analysis (Preprint)

Background

Objective

Methods

Results

Conclusions

Neuropsychological functioning in adult anorexia nervosa: A meta-analysis

Several studies have conceptualized neuropsychological dysfunction as part of the core pathology and defining behaviors seen in the eating disorder anorexia nervosa (AN). The aim of the current review was to synthesize the differences in neuropsychological test performance between individuals with AN and healthy controls, quantify and explain their heterogeneity. The search and screening procedures resulted in fifty studies that comprised 186 neuropsychological test results. Utilizing random-effects meta-analyses, the results revealed evidence for significant, moderate underperformance in people with AN in overall neuropsychological functioning (g¯ = -0.43, 95 % CI [-0.50, -0.36]). Weighted mean effect sizes ranged from g¯ = -0.53 for visuospatial abilities to g¯ = -0.10 for planning. Study and participant characteristics, including body mass index (BMI) and age, had significant moderator effects, especially on executive function, memory, and visuospatial abilities. The findings from the current study provide an extensive and comprehensive overview of the possible impairments in neuropsychological functioning in adult patients diagnosed with AN.

Nonplacebo Controls to Determine the Magnitude of Ergogenic Interventions: A Systematic Review and Meta-analysis

INTRODUCTION

Placebos are used as a control treatment that is meant to be indistinguishable from the active intervention. However, where substantive placebo effects may occur, studies that do not include a nonplacebo control arm may underestimate the overall effect of the intervention (active plus placebo components). This study aimed to determine the relative magnitude of the placebo effect associated with nutritional supplements (caffeine and extracellular buffers) by meta-analyzing data from studies containing both placebo and nonplacebo control sessions.

METHODS

Bayesian multilevel meta-analysis models were used to estimate pooled effects and express the placebo effect as a percentage of the overall intervention effect.

RESULTS

Thirty-four studies were included, with the median pooled effect size (ES0.5) indicating a very small (ES0.5 = 0.09 (95% credible interval (CrI), 0.01-0.17)) improvement in the performance of placebo compared with control. There was no moderating effect of exercise type (capacity or performance), exercise duration, or training status. The comparison between active intervention and control indicated a small to medium effect (ES0.5 = 0.37 (95% CrI, 0.20-0.56)). Expressed in relative terms, the placebo effect was equivalent to 25% (75% CrI, 16%-35%) and 59% (75% CrI, 34%-94%) of the total intervention effect for buffers and caffeine.

CONCLUSIONS

These results demonstrate a very small but potentially important placebo effect with nutritional supplementation studies. A substantive proportion of supplement effects may be due to placebo effects, with the relative proportion influenced by the magnitude of the overall ergogenic effect. Where feasible, intervention studies should use nonplacebo control-arm comparators to identify the proportion of the effect estimated to come from placebo effects and avoid underestimating the overall benefits that the physiological plus psychobiological aspects associated with an intervention provide in the real world.

Systematic review and meta-analysis of probiotic use on inflammatory biomarkers and disease prevention in cattle

The aim of this study was to appraise the available evidence on the effectiveness of probiotic treatment on mature cattle immunity, inflammation, and disease prevention. A systematic review with meta-analysis was conducted to analyse studies that were eligible to answer the following research question: "in cattle of at least 6-months of age, is the use of probiotics associated with immunomodulatory and inflammatory responses, and clinical disease outcomes?" Our literature search yielded 25 studies that fit the inclusion criteria. From these studies, only 19 were suitable for inclusion in the meta-analysis due to data limitations and differences in study population characteristics. Included studies were assessed for bias using a risk assessment tool adapted from the Cochrane Collaboration's tool for assessing risk of bias in randomised trials. GRADE guidelines were used to assess the quality of the body of evidence at the outcome level. The meta-analysis was performed using Review Manager and R. The overall quality of evidence at the outcome level was assessed as being very low. On average, the treatment effect on immunoglobulin G (IgG), serum amyloid A (SAA), haptoglobin (Hp) and β-hydroxybutyrate (BoHB) for cows receiving probiotics did not differ from control cows. Exposure to probiotics was not associated with reduced risk of reproductive disorders (pooled RR = 1.02 95 % CI = 0.81-1.27, P = 0.88). There is insufficient evidence to support any significant positive effects of probiotics on cattle immunity and disease prevention. This lack of consistent evidence could be due to dissimilarities in the design of the included studies such as differences in dosage, dose schedule, diet composition and/or physiological state of the host at the time of treatment.

Mental health problems in the general population during and after the first lockdown phase due to the SARS-Cov-2 pandemic: rapid review of multi-wave studies

AIMS

The SARS-Cov-2 pandemic and the lockdown response are assumed to have increased mental health problems in general populations compared to pre-pandemic times. The aim of this paper is to review studies on the course of mental health problems during and after the first lockdown phase.

METHODS

We conducted a rapid review of multi-wave studies in general populations with time points during and after the first lockdown phase. Repeated cross-sectional and longitudinal studies that utilised validated instruments were included. The main outcome was whether indicators of mental health problems have changed during and after the first lockdown phase. The study was registered with PROSPERO No. CRD42020218640.

RESULTS

Twenty-three studies with 56 indicators were included in the qualitative review. Studies that reported data from pre-pandemic assessments through lockdown indicated an increase in mental health problems. During lockdown, no uniform trend could be identified. After lockdown, mental health problems decreased slightly.

CONCLUSIONS

As mental health care utilisation indicators and data on suicides do not suggest an increase in demand during the first lockdown phase, we regard the increase in mental health problems as general distress that is to be expected during a global health crisis. Several methodological, pandemic-related, response-related and health policy-related factors need to be considered when trying to gain a broader perspective on the impact of the first wave of the pandemic and the first phase of lockdown on general populations' mental health.

Reversing Bonferroni

It is common for conclusions of empirical studies to depend on multiple significant outcomes. This practice may seem reasonable, but it has some unintended effects. In particular, the compound Type I error rate for multiple studies (the likelihood of concluding that an effect exists when it does not) can be much lower than that of the individual studies. This in itself is not a problem since a low Type I error rate is desirable. However, there is also an accompanying drop in power, meaning that the probability of finding support for a true effect is low. Currently, there is no standard statistical method for dealing with the hyper-conservative error rate and accompanying low power that results from investigations requiring multiple significant outcomes. Here, we propose a novel solution to this problem: We show that it is sometimes appropriate to reverse the logic of the classic Bonferroni correction and increase the significance criterion in order to maintain an intended compound Type I error rate across multiple tests. This reverse Bonferroni approach dramatically improves statistical power and encourages careful planning of statistical analyses prior to data collection. To avoid adding to the list of questionable research practices that seem to contaminate some psychological research, we suggest that reverse Bonferroni be restricted to situations where authors pre-register their analysis plans.

Prevalence of sending, receiving and forwarding sexts among youths: A three-level meta-analysis

By systematic review with a three-level, mixed-effects meta-analysis, this paper examines the prevalence of sexting experiences among youths aimed at analyzing conceptual and methodological moderators that might explain its heterogeneity. A search was conducted of five bibliographic databases and grey literature up until February 2020. The risk of bias in primary studies was assessed. A total of seventy-nine articles met the set inclusion criteria. Mean prevalences for sending, receiving and forwarding sexts were .14 (95% CI: .12, .17), .31 (95% CI: .26, .36) and .07 (95% CI: .05, .09), respectively, expressed as fractions over one. Moderator analyses showed that all sexting experiences increased with age (e.g., the mean prevalence for sending sexts at the age of 12 was .04, whereas, at the age of 16, it was .21) and year of data collection (e.g., the mean prevalence for sending sexts in studies collecting data in 2009 was .07, whereas, in studies collecting data in 2018, it was .33). Subgroup analysis revealed that studies with probabilistic samples led to significantly lower mean prevalences for the sexting experiences of sending (.08, 95% CI: .06, .11), receiving (.19, 95% CI: .15, .24) and forwarding sexts (.04, 95% CI: .03, .07). Self-reported administration procedures also led to more homogeneous prevalence estimates than interviews. Prevalence estimates also varied according to the type of media content (e.g., the mean prevalence for sending sexual text messages was .22, whereas, for sending sexual images or videos, it was .12). Overall, our meta-analysis results suggest high and increasing prevalences of sending and receiving sexts among youths.

Youth Initiated Mentoring: A Meta-analytic Study of a Hybrid Approach to Youth Mentoring

Youth initiated mentoring is a hybrid approach that empowers youth to identify and recruit natural mentors, potentially combining the strengths of informal mentoring relationships with the infrastructure and support provided by formal mentoring programs. This meta-analytic review examined the association between youth-initiated programs and youth outcomes across four domains: academic and vocational functioning, social-emotional development, physical health, and psychosocial problems. Results indicated that youth-initiated programs are significantly associated with positive youth outcomes. There was a small-to-medium effect size of g = 0.30 for youth-initiated programs overall, which was based on 14 studies with 11 independent samples (3594 youth and 169 effect sizes) from 2006 to 2019. The effect size was somewhat larger (g = 0.40) when controlling for possible selection bias, and was moderated by participant gender and year of publication. Implications for theory and practice regarding this relatively new approach to mentoring are discussed.