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Edited by
Richard Pinder, Imperial College of Science, Technology and Medicine, London,Christopher-James Harvey, Imperial College of Science, Technology and Medicine, London,Ellen Fallows, British Society of Lifestyle Medicine
Lifestyle Medicine is a practice grounded in evidence-based approaches, distinguishing it from unverified commercial wellness trends. It requires practitioners to critically interpret the evolving evidence base and communicate risks effectively to support shared decision making. While clinical trials for Lifestyle Medicine are less common than for pharmaceuticals, its interventions are nonetheless impactful and often preferred by patients. Epidemiology plays a crucial role in identifying associations between exposures and outcomes, although it cannot always establish causality. Understanding and communicating risk is vital, with absolute and relative risks offering different insights into the potential effects of interventions. The interpretation of evidence must consider both statistical and clinical significance, with confidence intervals providing a more nuanced understanding than p-values alone. Scepticism is necessary when interpreting clinical research to account for potential biases and confounding factors. Ultimately, consensus-driven approaches and trusted institutions guide practitioners in integrating Lifestyle Medicine into broader treatment guidelines.
A crucial step towards improving the care of people with fibromyalgia is understanding current practice. Our systematic review aims to address this by synthesising the global evidence around healthcare use in people with fibromyalgia, including its variation across groups of people, geographical locations, and over time.
Background:
Fibromyalgia is a chronic condition characterized by widespread pain alongside a broad range of non-pain symptoms. Its substantial impact on peoples’ lives and high prevalence mean that ensuring people with fibromyalgia receive evidence-based and appropriate care is a clinical and research priority. Whilst guidelines recommend that people with fibromyalgia receive a prompt diagnosis, care that focuses on non-pharmacological interventions, and in many countries should be predominantly managed in the community, existing evidence indicates they often wait many years for a diagnosis, commonly receive long-term opioid medicines, and see multiple hospital specialists.
Methods:
Relevant databases will be searched, with 25% of screening, data extraction, and quality appraisal conducted by two reviewers. Eligible studies will have evaluated healthcare use in adults with fibromyalgia using data obtained from electronic health record, registry, or insurance databases (providing generalizable findings in large, representative datasets). Data will be synthesized using meta-analysis and/or synthesis without meta-analysis where possible.
Results:
By providing an in-depth analysis of healthcare use and its variation in people with fibromyalgia, the results from this systematic review could be used to benchmark practice, inform targeted management strategies to those with the highest levels of healthcare use (and therefore care need), and provide insight into whether certain countries require specific guideline/policy changes.
In exploring deliberative dynamics within mini-publics, it has been observed that initial group-building activities play a crucial role in enhancing deliberative reasoning. However, the influence of liberal democratic practices such as voting mechanisms and the inclusion of strategic or representative stakeholders, on deliberative processes is not well understood. This study undertakes a comparative configurational meta-analysis (CCMA) of 22 minipublics to investigate how these liberal democratic elements influence deliberative reasoning. Results indicate that participants’ deliberative reasoning is significantly enhanced in contexts where initial group activities are coupled with prolonged periods of deliberation and where voting is minimised or absent. In contrast, the presence of voting mechanisms, strategic stakeholder involvement, and a high impact of minipublics on decision-making processes are associated with weaker, negative, or stable participant deliberative reasoning. These findings contribute to the broader discourse on the integration of deliberative and non-deliberative components within minipublics, highlighting the potential negative impact of strategic behaviour on the quality of deliberation.
Acceptance and commitment therapy (ACT) is recognized as an effective treatment for a variety of mental illnesses. Several meta-analyses have reported the efficacy of ACT in various mental and physical conditions, including depression, anxiety, and pain, but not for suicidality. This study aimed to determine the therapeutic effectiveness of ACT on suicidality through a systematic review and meta-analysis.
Methods:
Electronic databases such as PubMed, Embase, Scopus, and the Cochrane Library were searched for studies. The primary outcome measure was the effectiveness of ACT for suicidality which includes suicidal ideations and attempts.
Results:
This systematic review and meta-analysis included eight studies, all of which were judged to have a high risk of bias. In the meta-analysis, the pooled standardized mean difference for suicidal ideations was 1.122 (95% confidence interval (CI) = 0.261 to 1.982).
Conclusion:
This meta-analysis suggests that ACT is effective for reducing suicidal ideation, but the high risk of bias across studies should be considered as a major limitation. Further well-designed studies are needed to confirm these findings.
We report two meta-analyses on the determinants of antisocial behavior in experimental settings in which such behavior is not rationally motivated by pecuniary incentives. The first meta-analysis employs aggregate data from 95 published and unpublished studies (24,086 participants), using laboratory, field and online experiments carried out since 2000. We find that antisocial behavior depends significantly on the experimental setting, being highest in vendetta games and lowest in social dilemmas. As we find significant heterogeneity across the studies, including across game classes, in the second meta-analysis, we focus only on “Joy of Destruction” (JoD) and money-burning (MB) experiments, for which we have the most observations, 51 studies and around 16,784 participants. Overall, our findings suggest that procedural fairness and being observed by others reduce the frequency of antisocial behavior. Online and field experiments display more antisocial behavior than laboratory experiments. We also find that the strategy method biases antisocial behavior upward. However, we do not find evidence for a positive publication bias being correlated with higher destructive behavior, either in the general meta-analysis or in relation to JoD/MB experiments; if anything, there is evidence of a negative publication bias. The JoD/MB meta-analysis finds evidence of a price effect for destruction frequency, negative discrimination against outsiders, within-subject designs underestimating destructive behavior, and more antisocial behavior in one-shot interactions. Collectively, our results point to the value of more laboratory experiments that systematically build on paradigmatic experimental designs to enable comparability and the identification of key economic drivers of antisocial behavior.
A fundamental pillar of science is the estimation of the effect size of associations. However, this task is sometimes difficult and error-prone. To facilitate this process, the R package metaConvert automatically calculates and flexibly converts multiple effect size measures. It applies more than 120 formulas to convert any relevant input data into Cohen’s d, Hedges’ g, mean difference, odds ratio, risk ratio, incidence rate ratio, correlation coefficient, Fisher’s r-to-z transformed correlation coefficient, variability ratio, coefficient of variation ratio, or number needed to treat. Researchers unfamiliar with R can use this software through a browser-based graphical interface (https://metaconvert.org/). We hope this suite will help researchers in the life sciences and other disciplines estimate and convert effect sizes more easily and accurately.
Dirofilaria immitis and D. repens are globally distributed mosquito-borne parasitic filarial nematodes. Data on the prevalence of Dirofilaria spp. is not aggregated or publicly available at the national level for countries in North Africa and the Middle East. A systematic review and meta-analysis of publications describing cases of D. immitis and D. repens in 21 countries in North Africa and the Middle East was performed following PRISMA guidelines to estimate the prevalence of Dirofilaria spp. where national and regional estimates don’t exist. In total, 460 publications were reviewed, and 34 met all inclusion criteria for the meta-analysis model. This analysis found that the combined prevalence of Dirofilaria spp. in the included countries was 2.4% (95% CI: 1.6–3.6%; I2 = 81.7%, 95% CI: 78.6–84.3%). Moderator analysis showed a statistically significant difference in the prevalence estimate between diagnostic test methods used. The model detected a high degree of heterogeneity among studies and publication bias. Removal of model identified outliers reduced the estimated prevalence from 2.4% to 1.0%, whereas the trim-and-fill analysis suggested a higher adjusted prevalence (12%). Despite these findings, Dirofilaria spp. prevalence is likely dynamic due to seasonal variations in mosquito vector populations and differences in local mosquito control practices. Additional studies from the countries in and surrounding this region are needed to better identify key risk factors for Dirofilaria spp. in domestic canids and other species (including humans) to inform prevention and control decisions to limit further transmission.
Conventional meta-analyses (both fixed and random effects) of correlations are biased due to the mechanical relationship between the estimated correlation and its standard error. Simulations that are closely calibrated to match actual research conditions widely seen across correlational studies in psychology corroborate these biases and suggest two solutions: UWLS+3 and HS. UWLS+3 is a simple inverse-variance weighted average (the unrestricted weighted least squares) that adjusts the degrees of freedom and thereby reduces small-sample bias to scientific negligibility. UWLS+3 as well as the Hunter and Schmidt approach (HS) are less biased than conventional random-effects estimates of correlations and Fisher’s z, whether or not there is publication selection bias. However, publication selection bias remains a ubiquitous source of bias and false-positive findings. Despite the relationship between the estimated correlation and its standard error in the absence of selective reporting, the precision-effect test/precision-effect estimate with standard error (PET-PEESE) nearly eradicates publication selection bias. Surprisingly, PET-PEESE keeps the rate of false positives (i.e., type I errors) within their nominal levels under the typical conditions widely seen across psychological research whether there is publication selection bias, or not.
People with dementia (PwD) and their carers often consider maintaining good quality of life (QoL) more important than improvements in cognition or other symptoms of dementia. There is a clinical need for identifying interventions that can improve QoL of PwD. There are currently no evidence-based guidelines to help clinicians, patients and policy makers to make informed decisions regarding QoL in dementia.
Aims
To conduct the first comprehensive systematic review of all studies that investigated efficacy of any pharmacological or non-pharmacological intervention for improving QoL of PwD.
Method
Our review team identified eligible studies by comprehensively searching nine databases. We completed quality assessment, extracted relevant data and performed GRADE assessment of eligible studies. We conducted meta-analyses when three or more studies investigated an intervention for improving QoL of PwD.
Results
We screened 14 389 abstracts and included 324 eligible studies. Our meta-analysis confirmed level 1 evidence supporting the use of group cognitive stimulation therapy for improving QoL (standardised mean difference 0.25; P = 0.003) of PwD. Our narrative data synthesis revealed level 2 evidence supporting 42 non-pharmacological interventions, including those based on cognitive rehabilitation, reminiscence, occupational therapy, robots, exercise or music therapy. Current evidence supporting the use of any pharmacological intervention for improving QoL in dementia is limited.
Conclusions
Current evidence highlights the importance of non-pharmacological interventions and multidisciplinary care for supporting QoL of PwD. QoL should be prioritised when agreeing care plans. Further research focusing on QoL outcomes and investigating combined pharmacological and non-pharmacological interventions is urgently needed.
Dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD) are collectively called as Lewy body dementia (LBD). Despite the urgent clinical need, there is no reliable protein biomarker for LBD. Hence, we conducted the first comprehensive systematic review of all Differentially Abundant Proteins (DAP) in all tissues from people with LBD for advancing our understanding of LBD molecular pathology that is essential for facilitating discovery of novel diagnostic biomarkers and therapeutic targets for LBD.
Methods:
We identified eligible studies by comprehensively searching five databases and grey literature (PROSPERO protocol:CRD42020218889). We completed quality assessment and extracted relevant data. We completed narrative synthesis and appropriate meta-analyses. We analysed functional implications of all reported DAP using DAVID tools.
Results:
We screened 11,006 articles and identified 193 eligible studies. 305 DAP were reported and 16 were replicated in DLB. 37 DAP were reported and three were replicated in PDD. Our meta-analyses confirmed six DAP (TAU, SYUA, NFL, CHI3L1, GFAP, CLAT) in DLB, and three DAP (TAU, SYUA, NFL) in PDD. There was no replicated blood-based DAP in DLB or PDD. The reported DAP may contribute to LBD pathology by impacting misfolded protein clearance, dopamine neurotransmission, apoptosis, neuroinflammation, synaptic plasticity and extracellular vesicles.
Conclusion:
Our meta-analyses confirmed significantly lower CSF TAU levels in DLB and CSF SYUA levels in PDD, when compared to Alzheimer’s disease. Our findings indicate promising diagnostic biomarkers for LBD and may help prioritising molecular pathways for therapeutic target discovery. We highlight ten future research priorities based on our findings.
People with non-communicable diseases (NCDs) have a higher prevalence of comorbid depression than the general population. While previous research has shown that behavioural activation is effective for general depression, its efficacy and safety in treating depression associated with NCDs remains unclear.
Aims
To compare the efficacy and safety of behavioural activation against comparators in reducing depression symptoms in people with NCDs.
Method
We searched six databases from inception until 30 March 2023 (updated 23 September 2024) for randomised controlled trials (RCTs) comparing behavioural activation with comparators for depression in people with NCDs. Risk of bias was assessed using the Cochrane Collaboration’s ‘risk-of-bias 2 tool’. We calculated a random-effects, inverse-variance weighting meta-analysis.
Results
Of the 21 386 initial studies, 12 RCTs (with 2144 patients) comparing behavioural activation with any comparator on treatment outcomes for depression with comorbid NCD met the inclusion criteria. Six studies rated as low risk of bias. For short-term follow-ups (up to 6 months), meta-analysis showed behavioural activation had little effect on depression symptom improvement in people with NCDs (Hedges’ g = −0.24; 95% CI, −0.62 to 0.15), compared to comparators, with high heterogeneity (I2 = 91.91%). Of the 12 included studies, three RCTs provided data on adverse events occurring during the trial.
Conclusions
Evidence from this systematic review is not sufficient to draw clear conclusions about the efficacy and safety of behavioural activation for reducing depression symptoms in people with NCDs. Future reviews need to include more high-quality, well-designed RCTs to better understand the potential benefits of behavioural activation for comorbid depression.
Double-zero-event studies (DZS) pose a challenge for accurately estimating the overall treatment effect in meta-analysis (MA). Current approaches, such as continuity correction or omission of DZS, are commonly employed, yet these ad hoc methods can yield biased conclusions. Although the standard bivariate generalized linear mixed model (BGLMM) can accommodate DZS, it fails to address the potential systemic differences between DZS and other studies. In this article, we propose a zero-inflated bivariate generalized linear mixed model (ZIBGLMM) to tackle this issue. This two-component finite mixture model includes zero inflation for a subpopulation with negligible or extremely low risk. We develop both frequentist and Bayesian versions of ZIBGLMM and examine its performance in estimating risk ratios against the BGLMM and conventional two-stage MA that excludes DZS. Through extensive simulation studies and real-world MA case studies, we demonstrate that ZIBGLMM outperforms the BGLMM and conventional two-stage MA that excludes DZS in estimating the true effect size with substantially less bias and comparable coverage probability.
Network meta-analysis (NMA), also known as mixed treatment comparison meta-analysis or multiple treatments meta-analysis, extends conventional pairwise meta-analysis by simultaneously synthesizing multiple interventions in a single integrated analysis. Despite the growing popularity of NMA within comparative effectiveness research, it comes with potential challenges. For example, within-study correlations among treatment comparisons are rarely reported in the published literature. Yet, these correlations are pivotal for valid statistical inference. As demonstrated in earlier studies, ignoring these correlations can inflate mean squared errors of the resulting point estimates and lead to inaccurate standard error estimates. This article introduces a composite likelihood-based approach that ensures accurate statistical inference without requiring knowledge of the within-study correlations. The proposed method is computationally robust and efficient, with substantially reduced computational time compared to the state-of-the-science methods implemented in R packages. The proposed method was evaluated through extensive simulations and applied to two important applications including an NMA comparing interventions for primary open-angle glaucoma, and another comparing treatments for chronic prostatitis and chronic pelvic pain syndrome.
Substantial productivity increases have been reported when incentives are framed as losses rather than gains. Loss-framed contracts have also been reported to be preferred by workers. The results from our meta-analysis and real-effort experiment challenge these claims. The meta-analysis’ summary effect size of loss framing is a 0.16 SD increase in productivity. Whereas the summary effect size in laboratory experiments is a 0.33 SD, the summary effect size from field experiments is 0.02 SD. We detect evidence of publication biases among laboratory experiments. In a new laboratory experiment that addresses prior design weaknesses, we estimate an effect size of 0.12 SD. This result, in combination with the meta-analysis, suggests that the difference between the effect size estimates in laboratory and field experiments does not stem from the limited external validity of laboratory experiments, but may instead stem from a mix of underpowered laboratory designs and publication biases. Moreover, in our experiment, most workers preferred the gain-framed contract and the increase in average productivity is only detectable in the subgroup of workers (~ 20%) who preferred the loss-framed contracts. Based on the results from our experiment and meta-analysis, we believe that behavioral scientists should better assess preferences for loss-framed contracts and the magnitude of their effects on productivity before advocating for greater use of such contracts among private and public sector actors.
This paper reports the findings of a meta-analysis of 37 papers with 75 results from ultimatum game experiments. We find that on average the proposer offers 40% of the pie to the responder. This share is smaller for larger pie sizes and larger when a strategy method is used or when subjects are inexperienced. On average 16% of the offers is rejected. The rejection rate is lower for larger pie sizes and for larger shares offered. Responders are less willing to accept an offer when the strategy method is employed. As the results come from different countries, meta-analysis provides an alternative way to investigate whether bargaining behavior in ultimatum games differs across countries. We find differences in behavior of responders (and not of proposers) across geographical regions. With one exception, these differences cannot be attributed to various cultural traits on which for instance the cultural classifications of Hofstede (1991) and Inglehart (2000) are based.
We collect individual participant data from 70 papers that use laboratory experiments to examine individual tax evasion behavior (or “Tax Evasion Games”), in order to use meta-analysis to estimate the impacts of different public policy, experimental design and individual level variables on tax evasion choices. Our results show that standard enforcement variables like audits (including audit rules) and fines perform differently on the extensive and intensive margins. We find that other fiscal variables like a flat tax system, tax rates, and tax amnesties have unambiguous negative impacts on tax compliance, and that specific features of the experimental setting, such as how subjects are directed to report income, or whether taxes are redistributed to the participants or to a real life public good, have significant impacts on tax compliance. Our results also indicate that the demographic characteristics of the subjects (e.g., gender, experimental income, occupation, risk attitude) affect compliance.
Objective: To use meta-analysis techniques to assess the impact of various factors on the extent of cooperation in standard linear public goods experiments using the voluntary contributions mechanism.
Data Sources: Potentially relevant experiments were identified through searches of EconLit, the Internet Documents in Economics Access Service (IDEAS), and a survey article.
Review Methods: A total of 349 potentially relevant studies were identified. Of these, 27 (representing a total of 711 groups of participants) met the inclusion criteria. Data were abstracted from these studies using a standardized protocol. Results were analyzed using weighted ordinary least squares. Average group efficiency was the dependent variable.
Results: The marginal per capita return, communication, constant group composition over the session (“partners”), positive framing, and the use of children as subjects had a positive and significant effect (p < 0.05) on the average level of contribution to the public good. Heterogeneous endowments to subjects, experienced participants, and soliciting subjects’ beliefs regarding other participants’ behaviour prior to the start of the session/period had a negative and significant effect. A number of other factors were not identified as significant.
Conclusion: The meta-analysis results parallel several key findings from previous literature reviews. In addition, they offer parameter estimates and an analysis of significance based on the totality of the available research evidence. More consistent reporting of the results of experiments would greatly improve the ability to conduct this type of research.
One important determinant of voluntary contributions to public goods is the value of the public good relative to that of the forgone private good. Isaac, Walker and Thomas (1984) formalized this relation in the Marginal Per Capita Return (MPCR) and demonstrated its influence on the provision of linear public goods. This paper develops a parallel concept, in the context of a threshold public good, the Step Return (SR). After providing a meta-analysis of the effect of SR in previous experiments, we compare contributions in threshold public goods games with low, medium and high SRs. Results show that subjects respond to the SR in this setting just as they respond to the MPCR in the linear public goods setting: higher SRs lead to more contributions.
In this paper, we report a replication of Engel’s (Exp. Econ. 14(4):583–610, 2011) meta-study of dictator game experiments. We find Engel’s meta-study of dictator game experiments to be robust, with one important exception: the coding of the take-option (List in J. Polit. Econ. 115(3):482–493, 2007; Bardsley in Exp. Econ. 11(2):122–133, 2008; Cappelen et al. in Econ. Lett. 118(2):280–283, 2013). While Engel reports this as having no statistically significant effect, in our replications, we find an economically and statistically significant negative effect on giving in line with the relevant literature.
A key parameter estimated by lab and field experiments in economics is the individual discount rate—and the results vary widely. We examine the extent to which this variance can be attributed to observable differences in methods, subject pools, and potential publication bias. To address the model uncertainty inherent to such an exercise we employ Bayesian and frequentist model averaging. We obtain evidence consistent with publication bias against unintuitive results. The corrected mean annual discount rate is 0.33. Our findings also suggest that discount rates are independent across domains: people tend to be less patient when health is at stake compared to money. Negative framing is associated with more patience. Finally, the results of lab and field experiments differ systematically, and it also matters whether the experiment relies on students or uses broader samples of the population.