Browsing by Subject "META-ANALYSIS"

Sort by: Order: Results:

Now showing items 1-7 of 7
  • Chichorro, Filipe; Juslén, Aino; Cardoso, Pedro (2019)
    Biodiversity is shrinking rapidly, and despite our efforts only a small part of it has been assessed for extinction risk. Identifying the traits that make species vulnerable might help us to predict the status for those less known. We gathered information on the relationships between traits and extinction risk from 173 publications, across all taxa, spatial scales and biogeographical regions, in what we think it is the most comprehensive compilation to date. We aimed to identify (1) taxonomical and spatial biases, and (2) statistically robust and generalizable predictors of extinction risk through the use of meta-analyses. Vertebrates and the Palaearctic are the most studied taxon and region because of higher accumulation of data in these groups. Among the many traits that have been suggested to be predictors, only three had enough data for meta-analyses. Two of them are potentially useful in assessing risk for the lesser-known species: regardless of the taxon, species with small range and narrow habitat breadth are more vulnerable to extinction. Contrastingly, body size (the most studied trait) did not present a consistently positive or negative response. We hypothesize that the relationship between body size and extinction risk is shaped by different aspects, namely the phenomena represented by body size depending on the taxonomic group. To increase our understanding of the drivers of extinction, further studies should focus on understudied groups such as invertebrates and fungi and regions such as the tropics and expand the number of traits in comparative analyses that should avoid current biases.
  • Matikainen, M.; Aro, E.; Vironen, J.; Kössi, J.; Hulmi, T.; Silvasti, S.; Ilves, I.; Hertsi, M.; Mustonen, K.; Paajanen, H. (2018)
    Chronic pain after inguinal hernioplasty is the foremost side-effect up to 10-30% of patients. Mesh fixation may influence on the incidence of chronic pain after open anterior mesh repairs. Some 625 patients who underwent open anterior mesh repairs were randomized to receive one of the three meshes and fixations: cyanoacrylate glue with low-weight polypropylene mesh (n = 216), non-absorbable sutures with partially absorbable mesh (n = 207) or self-gripping polyesther mesh (n = 202). Factors related to chronic pain (visual analogue scores; VAS ae 30, range 0-100) at 1 year postoperatively were analyzed using logistic regression method. A second analysis using telephone interview and patient records was performed 2 years after the index surgery. At index operation, all patient characteristics were similar in the three study groups. After 1 year, chronic inguinal pain was found in 52 patients and after 2 years in only 16 patients with no difference between the study groups. During 2 years' follow-up, three (0.48%) patients with recurrences and five (0.8%) patients with chronic pain were re-operated. Multivariate regression analysis indicated that only new recurrent hernias and high pain scores at day 7 were predictive factors for longstanding groin pain (p = 0.001). Type of mesh or fixation, gender, pre-operative VAS, age, body mass index or duration of operation did not predict chronic pain. Only the presence of recurrent hernia and early severe pain after index operation seemed to predict longstanding inguinal pain.
  • Aulbach, Matthias Burkard; Knittle, Keegan Phillip; Haukkala, Ari Heikki (2019)
    Dual-process models integrate deliberative and impulsive mental systems and predict dietary behaviours better than deliberative processes alone. Computerised tasks such as the Go/No-Go, Stop-Signal, Approach-Avoidance, and Evaluative Conditioning have been used as interventions to directly alter implicit biases. This meta-analysis examines the effects of these tasks on dietary behaviours, explores potential moderators of effectiveness, and examines implicit bias change as a proposed mechanism. Thirty randomised controlled trials testing implicit bias interventions (47 comparisons) were included in a random-effects meta-analysis, which indicated small cumulative effects on eating-related behavioural outcomes (g = -0.17, CI95 = [-0.29; -0.05], p = .01) and implicit biases (g = -0.18, CI95 = [-0.34; -0.02], p = .02). Task type moderated these effects, with Go/No-Go tasks producing larger effects than other tasks. Effects of interventions on implicit biases were positively related to effects on eating behaviour (B = 0.42, CI95 = [0.02; 0.81], p = .03). Go/No-Go tasks seem to have most potential for altering dietary behaviours through implicit processes. While changes in implicit biases seem related to the effects of these interventions on dietary outcomes, more research should explore whether repeated exposure to implicit bias interventions may have any practical intervention value in real world settings.
  • Hemilä, Harri; Friedrich, Jan O. (2019)
    BACKGROUND: The relative scale adjusts for baseline variability and therefore may lead to findings that can be generalized more widely. It is routinely used for the analysis of binary outcomes but only rarely for continuous outcomes. Our objective was to compare relative vs absolute scale pooled outcomes using data from a recently published Cochrane systematic review that reported only absolute effects of inhaled β2-agonists on exercise-induced decline in forced-expiratory volumes in 1 s (FEV1). METHODS: From the Cochrane review, we selected placebo-controlled cross-over studies that reported individual participant data (IPD). Reversal in FEV1 decline after exercise was modeled as a mean uniform percentage point (pp) change (absolute effect) or average percent change (relative effect) using either intercept-only or slope-only, respectively, linear mixed-effect models. We also calculated the pooled relative effect estimates using standard random-effects, inverse-variance-weighting meta-analysis using study-level mean effects. RESULTS: Fourteen studies with 187 participants were identified for the IPD analysis. On the absolute scale, β2-agonists decreased the exercise-induced FEV1 decline by 28 pp., and on the relative scale, they decreased the FEV1 decline by 90%. The fit of the statistical model was significantly better with the relative 90% estimate compared with the absolute 28 pp. estimate. Furthermore, the median residuals (5.8 vs. 10.8 pp) were substantially smaller in the relative effect model than in the absolute effect model. Using standard study-level meta-analysis of the same 14 studies, β2-agonists reduced exercise-induced FEV1 decline on the relative scale by a similar amount: 83% or 90%, depending on the method of calculating the relative effect. CONCLUSIONS: Compared with the absolute scale, the relative scale captures more effectively the variation in the effects of β2-agonists on exercise-induced FEV1-declines. The absolute scale has been used in the analysis of FEV1 changes and may have led to sub-optimal statistical analysis in some cases. The choice between the absolute and relative scale should be determined based on biological reasoning and empirical testing to identify the scale that leads to lower heterogeneity.
  • Rantala, Elina S.; Hernberg, Micaela; Kivelä, Tero T. (2019)
  • Hemilä, Harri Olavi; Rezaei, Yousef (2017)
    McCullough et al. (1) reviewed the pathophysiology and treatment options for contrast-induced acute kidney injury (CI-AKI). They stated that no effective adjunctive pharmaceutical had been demonstrated that either prevented or treated CI-AKI. However, they also suggested that of the agents being investigated, statins were the most promising. We would like to point out that strong evidence has also emerged regarding the effect of vitamin E against CI-AKI, which was not mentioned in their review.
  • Rezaei, Yousef; Hemilä, Harri (2017)
    A recent meta-analysis by Su et al. compared 12 different prophylactic interventions against contrast medium–induced acute kidney injury (CIAKI). In their meta-analysis, Su et al. pooled different vitamins to a single group of “vitamins and analogues” but in so doing did not take into account that vitamin C is water soluble whereas vitamin E is fat soluble, and therefore their relative effects might be different... Su et al. had identified 3 randomized trials on vitamin E prophylaxis against CIAKI. We pooled the results of these 3 studies and calculated a pooled estimate of RR = 0.38 (95% CI 0.24-0.62), indicating that vitamin E significantly prevented CIAKI.