Browsing by Subject "Meta analysis"
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- PublicationEmbargoA meta-review of transparency and reproducibility-related reporting practices in published meta-analyses on clinical psychological interventions (2000–2020)(Springer, 2022-02) López Nicolás, Rubén; López López, José Antonio; Rubio Aparicio, María; Sánchez Meca, Julio; Psicología Básica y MetodologíaMeta-analysis is a powerful and important tool to synthesize the literature about a research topic. Like other kinds of research,meta-analyses must be reproducible to be compliant with the principles of the scientific method. Furthermore, reproducible meta-analyses can be easily updated with new data and reanalysed applying new and more refined analysis techniques. We attemptedto empirically assess the prevalence of transparency and reproducibility-related reporting practices in published meta-analysesfrom clinical psychology by examining a random sample of 100 meta-analyses. Our purpose was to identify the key points thatcould be improved, with the aim of providing some recommendations for carrying out reproducible meta-analyses. We conduct-ed a meta-review of meta-analyses of psychological interventions published between 2000 and 2020. We searched PubMed,PsycInfo and Web of Science databases. A structured coding form to assess transparency indicators was created based onprevious studies and existing meta-analysis guidelines. We found major issues concerning: completely reproducible searchprocedures report, specification of the exact method to compute effect sizes, choice of weighting factors and estimators, lackof availability of the raw statistics used to compute the effect size and of interoperability of available data, and practically totalabsence of analysis script code sharing. Based on our findings, we conclude with recommendations intended to improve thetransparency, openness, and reproducibility-related reporting practices of meta-analyses in clinical psychology and related areas.
- PublicationOpen AccessAssociation between attitudes toward violence and violent behavior in the school context: a systematic review and correlational meta-analysis(Elsevier, 2022-04) López Nicolás, Rubén; López López, Reyes; Puente López, Esteban; Ruiz Hernández, José Antonio; Pina, David; Psiquiatría y Psicología SocialBackground/Objective: Both theoretical proposals and empirical work point to a common concurrence between attitudes toward school violence and violent behavior. Studies often address this issue superficially or within intervention programs. Our objective is to describe the results of a systematic review and to conduct a meta-analysis exploring these associations. Method: A systematic review was conducted in the main databases. Effect sizes were calculated and synthesized using random-effects meta-analysis to estimate the relationship between attitudes toward violence and school violence. A meta-regression was performed for the moderator analysis of sex and age. Results: The literature search strategy produced 12,293 articles. The review process produced a final result of 23 studies. Our results estimate a significant positive relationship (r = .368 p < .001; 95% CI [.323, .412]) between attitudes toward violence and school violence in children and adolescents. Conclusions: This study allows us to quantify with an adequate degree of specificity the attitude-behavior relationship in the school context. These results may facilitate future researchers to design programs that address this specificity in order to improve school climate. More research is needed using validated instruments to further specify the type of attitudes that have the greatest influence on the manifestation of school violence. -------------------
- PublicationRestrictedEffects of salinity changes on aquatic organisms in a multiple stressor context(The Royal Society, 2019-01-21) Velasco, Josefa; Cayetano Gutiérrez-Cánovas, Cayetano; Botella Cruz, María; Sánchez Fernández, David; Arribas, Paula; Carbonell, José Antonio; Millán, Andrés; Pallarés, Susana; Ecología e HidrologíaUnder global change, the ion concentration of aquatic ecosystems is changing worldwide. Many freshwater ecosystems are being salinized by anthropogenic salt inputs, whereas many naturally saline ones are being diluted by agricultural drainages. This occurs concomitantly with changes in other stressors, which can result in additive, antagonistic or synergistic effects on organisms. We reviewed experimental studies that manipulated salinity and other abiotic stressors, on inland and transitional aquatic habitats, to (i) synthesize their main effects on organisms' performance, (ii) quantify the frequency of joint effect types across studies and (iii) determine the overall individual and joint effects and their variation among salinity–stressor pairs and organism groups using meta-analyses. Additive effects were slightly more frequent (54%) than non-additive ones (46%) across all the studies (n = 105 responses). However, antagonistic effects were dominant for the stressor pair salinity and toxicants (44%, n = 43), transitional habitats (48%, n = 31) and vertebrates (71%, n = 21). Meta-analyses showed detrimental additive joint effects of salinity and other stressors on organism performance and a greater individual impact of salinity than the other stressors. These results were consistent across stressor pairs and organism types. These findings suggest that strategies to mitigate multiple stressor impacts on aquatic ecosystems should prioritize restoring natural salinity concentrations. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.
- PublicationOpen AccessHeterogeneity estimation in meta-analysis of standardized mean differences when the distribution of random effects departs from normal: a Monte Carlo simulation study(BioMed Central, 2023-01-17) Blázquez Rincón, Desirée; Sánchez Meca, Julio; Botella, Juan; Suero, Manuel; Psicología Básica y MetodologíaBackground Advantages of meta-analysis depend on the assumptions underlying the statistical procedures used being met. One of the main assumptions that is usually taken for granted is the normality underlying the population of true effects in a random-effects model, even though the available evidence suggests that this assumption is often not met. This paper examines how 21 frequentist and 24 Bayesian methods, including several novel procedures, for computing a point estimate of the heterogeneity parameter ( ) perform when the distribution of random effects departs from normality compared to normal scenarios in meta-analysis of standardized mean differences. Methods A Monte Carlo simulation was carried out using the R software, generating data for meta-analyses using the standardized mean difference. The simulation factors were the number and average sample size of primary studies, the amount of heterogeneity, as well as the shape of the random-effects distribution. The point estimators were compared in terms of absolute bias and variance, although results regarding mean squared error were also discussed. Results Although not all the estimators were affected to the same extent, there was a general tendency to obtain lower and more variable estimates as the random-effects distribution departed from normality. However, the estimators ranking in terms of their absolute bias and variance did not change: Those estimators that obtained lower bias also showed greater variance. Finally, a large number and sample size of primary studies acted as a bias-protective factor against a lack of normality for several procedures, whereas only a high number of studies was a variance-protective factor for most of the estimators analyzed. Conclusions Although the estimation and inference of the combined effect have proven to be sufficiently robust, our work highlights the role that the deviation from normality may be playing in the meta-analytic conclusions from the simulation results and the numerical examples included in this work. With the aim to exercise caution in the interpretation of the results obtained from random-effects models, the tau2() R function is made available for obtaining the range of values computed from the 45 estimators analyzed in this work, as well as to assess how the pooled effect, its confidence and prediction intervals vary according to the estimator chosen.
- PublicationOpen AccessLe développement de l’éducation interculturelle par l’enseignement-apprentissage du français langue étrangère (FLE): une analyse de la littérature.(Universidad de Murcia, Servicio de Publicaciones., 2021-11-24) Chamseddine Habib Allah, Mohamed; Fernández Pérez, Amalia; Facultades, Departamentos, Servicios y Escuelas::Departamentos de la UMU::Teoría e Historia de la EducaciónAbstract: There is no doubt that intercultural education in school contexts is not making any progress. To Inquire about this, the main objective of this contribution was to describe the importance of approaching intercultural education, through a teaching-learning process of FLE, by means of a literature review. Our exploration is executed by means of a meta-analysis carried out with 22 research articles of the most relevant studies carried out, both nationally and internationally, published in scientific journals in the years 2006-2020, in the Dialnet, Scopus database. The results reveal that, at the state level, there is hardly any empirical research associated with the contributions of the FLE in the development of intercultural education. Moreover, it is remarkable the implicit and explicit absence of intercultural competences in the curriculum of the different works analyzed. The few studies selected are characterized by their good intentions to pretend the implementation with some brushstrokes of intercultural education in the field of FLE, however, this do not clearly represent the different cultural realities of their school contexts, they are focusing their interest on visualizing certain cultures and hiding others. It ends with proposals, such as the introduction of real supports to intercultural education, which avoid the consequences of cultural biases in the curriculum, which reproduce social inequalitie.
- PublicationRestrictedSystematic review and meta-analysis: an empirical approach to defining treatment response and remission in pediatric obsessive-compulsive disorder(Elsevier, 2022-04) Farath, Luis C.; Rosa Alcázar, Ana Isabel; Rosa Alcázar, Ángel; Rozenman, Michelle et al.; Personalidad, Evaluación y Tratamiento PsicológicosObjective: A lack of universal definitions for response and remission in pediatric obsessive-compulsive disorder (OCD) has hampered the comparability of results across trials. To address this problem, we conducted an individual participant data diagnostic test accuracy meta-analysis to evaluate the discriminative ability of the Children’s Yale Brown Obsessive-Compulsive Scale (CY-BOCS) in determining response and remission. We also aimed to generate empirically derived cutoffs on the CY-BOCS for these outcomes. Method: A systematic review of PubMed, PsycINFO, Embase and CENTRAL identified 5,401 references; 42 randomized controlled clinical trials were considered eligible, and 21 provided data for inclusion (N 1,234). Scores of 2 in the Clinical Global Impressions Improvement and Severity scales were chosen to define response and remission, respectively. A 2-stage, random-effects meta-analysis model was established. The area under the curve (AUC) and the Youden Index were computed to indicate the discriminative ability of the CY-BOCS and to guide for the optimal cutoff, respectively. Results: The CY-BOCS had sufficient discriminative ability to determine response (AUC ¼ 0.89) and remission (AUC ¼ 0.92). The optimal cutoff for response was a 35% reduction from baseline to posttreatment (sensitivity ¼ 83.9, 95% CI ¼ 83.7 84.1; specificity ¼ 81.7, 95% CI ¼ 81.5 81.9). The optimal cutoff for remission was a posttreatment raw score of 12 (sensitivity ¼ 82.0, 95% CI ¼ 81.8 82.2; specificity ¼ 84.6, 95% CI ¼ 84.4 84.8). Conclusion: Meta-analysis identified empirically optimal cutoffs on the CY-BOCS to determine response and remission in pediatric OCD randomized controlled clinical trials. Systematic adoption of standardized operational definitions for response and remission will improve comparability across trials for pediatric OCD.
- PublicationRestrictedTemporal trends in sperm count: a systematic review and meta-regression analysis of samples collected globally in the 20th and 21st centuries.(Oxford University Press, 2022-11-15) Levine, Hagai; Jørgensen, Niels; Martino Andrade, Anderson; Mendiola Olivares, Jaime; Weksler Derri, Dan; Jolles, Maya; Pinotti, Rachel; Swan, Shanna H.; Ciencias SociosanitariasBACKGROUND: Numerous studies have reported declines in semen quality and other markers of male reproductive health. Our previous meta-analysis reported a significant decrease in sperm concentration (SC) and total sperm count (TSC) among men from North America–Europe–Australia (NEA) based on studies published during 1981–2013. At that time, there were too few studies with data from South/Central America–Asia–Africa (SAA) to reliably estimate trends among men from these continents. OBJECTIVE AND RATIONALE: The aim of this study was to examine trends in sperm count among men from all continents. The broader implications of a global decline in sperm count, the knowledge gaps left unfilled by our prior analysis and the controversies surrounding this issue warranted an up-to-date meta-analysis. SEARCH METHODS: We searched PubMed/MEDLINE and EMBASE to identify studies of human SC and TSC published during 2014–2019. After review of 2936 abstracts and 868 full articles, 44 estimates of SC and TSC from 38 studies met the protocol criteria. Data were extracted on semen parameters (SC, TSC, semen volume), collection year and covariates. Combining these new data with data from our previous meta-analysis, the current meta-analysis includes results from 223 studies, yielding 288 estimates based on semen samples collected 1973–2018. Slopes of SC and TSC were estimated as functions of sample collection year using simple linear regression as well as weighted meta-regression. The latter models were adjusted for predetermined covariates and examined for modification by fertility status (unselected by fertility versus fertile), and by two groups of continents: NEA and SAA. These analyses were repeated for data collected post-2000. Multiple sensitivity analyses were conducted to examine assumptions, including linearity. OUTCOMES: Overall, SC declined appreciably between 1973 and 2018 (slope in the simple linear model: –0.87 million/ml/year, 95% CI: –0.89 to –0.86; P<0.001). In an adjusted meta-regression model, which included two interaction terms [time fertility group (P¼0.012) and time continents (P¼0.058)], declines were seen among unselected men from NEA (–1.27; –1.78 to –0.77; P<0.001) and unselected men from SAA (–0.65; –1.29 to –0.01; P¼0.045) and fertile men from NEA (–0.50; –1.00 to –0.01; P¼0.046). Among unselected men from all continents, the mean SC declined by 51.6% between 1973 and 2018 (–1.17: –1.66 to –0.68; P<0.001). The slope for SC among unselected men was steeper in a model restricted to post-2000 data (–1.73: –3.23 to –0.24; P¼0.024) and the percent decline per year doubled, increasing from 1.16% post-1972 to 2.64% post-2000. Results were similar for TSC, with a 62.3% overall decline among unselected men (–4.70 million/year; –6.56 to –2.83; P<0.001) in the adjusted meta-regression model. All results changed only minimally in multiple sensitivity analyses. WIDER IMPLICATIONS: This analysis is the first to report a decline in sperm count among unselected men from South/Central America–Asia–Africa, in contrast to our previous meta-analysis that was underpowered to examine those continents. Furthermore, data suggest that this world-wide decline is continuing in the 21st century at an accelerated pace. Research on the causes of this continuing decline and actions to prevent further disruption of male reproductive health are urgently needed.
- PublicationOpen AccessThe association between muscle dysmorphia and eating disorder symptomatology: a systematic review and meta-analysis(Akadémiai Kiadó, 2019-09-11) Badenes Ribera, Laura; Rubio Aparicio, María; Sánchez Meca, Julio; Fabris, Matteo Angelo; Longobardi, Claudio; Psicología Básica y MetodologíaBackground and aims Research shows inconsistent findings about the link between muscle dysmorphia (MD) and eating disorder (ED) symptomatology. The aim of this study is to synthesize the scientific evidence available on this topic, the researchers conducted a systematic review and meta-analysis. Methods The literature search enabled us to identify 39 published articles, which provided 36 independent estimations of the correlation between the two variables. Results Our analysis found a positive association between MD and ED symptoms (r+ = .36; 95% CI = 0.30, 0.41). Moderator analyses showed that the type of sample and the tools for assessing MD and ED were statistically associated with the MD–ED effect sizes. The methodological quality of the studies exhibited a positive, statistically significant association with the MD–ED effect sizes. Conclusions Higher levels of MD were related to greater ED symptomatology, but several study characteristics may moderate the association between the two variables. In this study, we discuss limitations and implications for clinical practice and future research.
- PublicationEmbargoThe current situation of inorganic elements in marine turtles: a general review and meta-analysis(Elsevier, 2017-06-24) Cortés-Gómez, Adriana A.; Romero, Diego; Girondot, Marc; Ciencias SociosanitariasInorganic elements (Pb, Cd, Hg, Al, As, Cr, Cu, Fe, Mn, Ni, Se and Zn) are present globally in aquatic systems and their potential transfer to marine turtles can be a serious threat to their health status. The environmental fate of these contaminants may be traced by the analysis of turtle tissues. Loggerhead turtles (Caretta caretta) are the most frequently investigated of all the sea turtle species with regards to inorganic elements, followed by Green turtles (Chelonia mydas); all the other species have considerably fewer studies. Literature shows that blood, liver, kidney and muscle are the tissues most frequently used for the quantification of inorganic elements, with Pb, Cd, Cu and Zn being the most studied elements. Chelonia mydas showed the highest concentrations of Cr in muscle (4.8 ± 0.12), Cu in liver (37 ± 7) and Mg in kidney (17 mg g 1 ww), Cr and Cu from the Gulf of Mexico and Mg from Japanese coasts; Lepidochelys olivacea presented the highest concentrations of Pb in blood (4.46 5) and Cd in kidney (150 ± 110 mg g 1 ww), both from the Mexican Pacific; Caretta caretta from the Mediterranean Egyptian coast had the highest report of Hg in blood (0.66 ± 0.13 mg g 1 ww); and Eretmochelys imbricata from Japan had the highest concentration of As in muscle (30 ± 13 13 mg g 1 ww). The meta-analysis allows us to examine some features that were not visible when data was analyzed alone. For instance, Leatherbacks show a unique pattern of concentration compared to other species. Additionally, contamination of different tissues shows some tendencies independent of the species with liver and kidney on one side and bone on the other being different from other tissues. This review provides a general perspective on the accumulation and distribution of these inorganic elements alongside existing information for the 7 sea turtle species.
- PublicationRestrictedThe Inventory of Problems–29 (IOP-29): a systematic review and bivariate diagnostic test accuracy meta-analysis.(American Psychological Association, 2023-01-12) Pina, David; Puente López, Esteban; López Nicolás, Rubén; Iguacel, Isabel; Arce, Ramón; Psiquiatría y Psicología SocialThe Inventory of Problems–29 (IOP-29) is a 29-item self-administered symptom validity test (SVT) that assesses the credibility of clinical presentations related to posttraumatic stress disorder, depression/anxiety, psychosis, cognitive impairment and combination thereof. To date, no publications have summarized the classification accuracy of the IOP-29 using a bivariate meta-analytical approach that preserves the two-dimensional nature of the estimators. Our objective was to conduct a systematic review and bivariate diagnostic test accuracy meta-analysis of the IOP-29 according to the relevant guidelines. Twenty-one independent samples were included, with a total sample size of 4,163 participants. The results indicated that the IOP-29 is able to discriminate adequately between instructed simulators and healthy controls/clinical patients. Using the recommended cutoff (False Disorder Probability Score [FDS], ≥ .50), a sensitivity of 82% was achieved, maintaining specificity at 93% (false positive rate of 7%). The language of the test and the type of comparison group have been identified as possible sources of heterogeneity. Specificity decreases for the non-English version of the IOP-29, for the FDS ≥ .30, and also decreases for studies using clinical controls, for all three cutoff scores. In general, our findings support the usefulness of the IOP-29 as an SVT; however, most of the included studies use a simulation design and have been coauthored by the test authors. Likewise, about half of the studies did not include bona fide patient controls but only nonclinical controls. The results obtained are highly promising, but further research, especially that using the criterion group paradigm, is recommended.
- PublicationOpen AccessTime-restricted eating and bone health: a systematic review with meta-analysis(MDPI, 2024-03-18) Fernández Rodríguez, Rubén; Garrido Miguel, Miriam; Bizzozero Peroni, Bruno; Díaz Goñi, Valentina; Rodríguez Gutiérrez, Eva; Guzmán Pavón, María José; Meseguer Henarejos, Ana Belén; Torres Costoso, Ana; FisioterapiaTime-restricted eating (TRE) has emerged as a dietary strategy that restricts food consumption to a specific time window and is commonly applied to facilitate weight loss. The benefits of TRE on adipose tissue have been evidenced in human trials and animal models; however, its impact on bone tissue remains unclear. To systematically synthesize and examine the evidence on the impact of TRE on bone health (bone mineral content (BMC), bone mineral density (BMD), and bone turnover factors), PubMed, Scopus, Cochrane CENTRAL, andWeb of Science databases were systematically explored from inception to 1 October 2023 searching for randomized controlled trials (RCTs) aimed at determining the effects of TRE on bone health in adults (≥18 years). The Cochrane Handbook and the PRISMA recommendations were followed. A total of seven RCTs involving 313 participants (19 to 68 years) were included, with an average length of 10.5 weeks (range: 4 to 24 weeks). Despite the significant weight loss reported in five out of seven studies when compared to the control, our meta-analysis showed no significant difference in BMD (g/cm2) between groups (MD = −0.009, 95% CI: −0.026 to 0.009, p = 0.328; I2 = 0%). BMC and bone turnover markers between TRE interventions and control conditions were not meta-analyzed because of scarcity of studies (less than five). Despite its short-term benefits on cardiometabolic health, TRE did not show detrimental effects on bone health outcomes compared to those in the control group. Nevertheless, caution should be taken when interpreting our results due to the scarcity of RCTs adequately powered to assess changes in bone outcomes.