Radboud University Nijmegen

About: Radboud University Nijmegen is a education organization based out in Nijmegen, Gelderland, Netherlands. It is known for research contribution in the topics: Population & Context (language use). The organization has 35417 authors who have published 83035 publications receiving 3285064 citations. The organization is also known as: Catholic University of Nijmegen & Radboud University.

Many Labs 2: Investigating Variation in Replicability Across Samples and Settings

Abstract: We conducted preregistered replications of 28 classic and contemporary published findings, with protocols that were peer reviewed in advance, to examine variation in effect magnitudes across samples and settings. Each protocol was administered to approximately half of 125 samples that comprised 15,305 participants from 36 countries and territories. Using the conventional criterion of statistical significance (p < .05), we found that 15 (54%) of the replications provided evidence of a statistically significant effect in the same direction as the original finding. With a strict significance criterion (p < .0001), 14 (50%) of the replications still provided such evidence, a reflection of the extremely high-powered design. Seven (25%) of the replications yielded effect sizes larger than the original ones, and 21 (75%) yielded effect sizes smaller than the original ones. The median comparable Cohen’s ds were 0.60 for the original findings and 0.15 for the replications. The effect sizes were small (< 0.20) in 16 of the replications (57%), and 9 effects (32%) were in the direction opposite the direction of the original effect. Across settings, the Q statistic indicated significant heterogeneity in 11 (39%) of the replication effects, and most of those were among the findings with the largest overall effect sizes; only 1 effect that was near zero in the aggregate showed significant heterogeneity according to this measure. Only 1 effect had a tau value greater than .20, an indication of moderate heterogeneity. Eight others had tau values near or slightly above .10, an indication of slight heterogeneity. Moderation tests indicated that very little heterogeneity was attributable to the order in which the tasks were performed or whether the tasks were administered in lab versus online. Exploratory comparisons revealed little heterogeneity between Western, educated, industrialized, rich, and democratic (WEIRD) cultures and less WEIRD cultures (i.e., cultures with relatively high and low WEIRDness scores, respectively). Cumulatively, variability in the observed effect sizes was attributable more to the effect being studied than to the sample or setting in which it was studied.

Self management for patients with chronic obstructive pulmonary disease

Abstract: Background Self management interventions help patients with chronic obstructive pulmonary disease (COPD) acquire and practise the skills they need to carry out disease-specific medical regimens, guide changes in health behaviour and provide emotional support to enable patients to control their disease. Since the first update of this review in 2007, several studies have been published. The results of the second update are reported here. Objectives 1. To evaluate whether self management interventions in COPD lead to improved health outcomes. 2. To evaluate whether self management interventions in COPD lead to reduced healthcare utilisation. Search methods We searched the Cochrane Airways Group Specialised Register of trials (current to August 2011). Selection criteria Controlled trials (randomised and non-randomised) published after 1994, assessing the efficacy of self management interventions for individuals with COPD, were included. Interventions with fewer than two contact moments between study participants and healthcare providers were excluded. Data collection and analysis Two review authors independently assessed trial quality and extracted data. Investigators were contacted to ask for additional information. When appropriate, study results were pooled using a random-effects model. The primary outcomes of the review were health-related quality of life (HRQoL) and number of hospital admissions. Main results Twenty-nine studies were included. Twenty-three studies on 3189 participants compared self management versus usual care; six studies on 499 participants compared different components of self management on a head-to-head basis. Although we included non-randomised controlled clinical trials as well as RCTs in this review, we restricted the primary analysis to RCTs only and reported these trials in the abstract. In the 23 studies with a usual care control group, follow-up time ranged from two to 24 months. The content of the interventions was diverse. A statistically relevant effect of self management on HRQoL was found (St George's Respiratory Questionnaire (SGRQ) total score, mean difference (MD) -3.51, 95% confidence interval (CI) -5.37 to -1.65, 10 studies, 1413 participants, moderate-quality evidence). Self management also led to a lower probability of respiratory-related hospitalisations (odds ratio (OR) 0.57, 95% CI 0.43 to 0.75, nine studies, 1749 participants, moderate-quality evidence) and all cause hospitalisations (OR 0.60; 95% CI 0.40 to 0.89, 6 studies, 1365 participants, moderate-quality evidence). Over one year of follow-up, eight (95% CI 5 to 14) participants with a high baseline risk of respiratory-related hospital admission needed to be treated to prevent one participant with at least one hospital admission, and 20 (95% CI 15 to 35) participants with a low baseline risk of hospitalisation needed to be treated to prevent one participant with at least one respiratory-related hospital admission. No statistically significant effect of self management on mortality (OR 0.79, 95% CI 0.58 to 1.07, 8 studies, 2134 participants, very low-quality evidence) was detected. Also, dyspnoea measured by the (modified) Medical Research Council Scale ((m)MRC) was reduced in individuals who participated in self management (MD -0.83, 95% CI -1.36 to -0.30, 3 studies, 119 participants, low-quality evidence). The difference in exercise capacity as measured by the six-minute walking test was not statistically significant (MD 33.69 m, 95% CI -9.12 to 76.50, 6 studies, 570 participants, very low-quality evidence). Subgroup analyses depending on the use of an exercise programme as part of the intervention revealed no statistically significant differences between studies with and without exercise programmes in our primary outcomes of HRQoL and respiratory-related hospital admissions. We were unable to pool head-to-head trials because of heterogeneity among interventions and controls; thus results are presented narratively within the review. Authors' conclusions Self management interventions in patients with COPD are associated with improved health-related quality of life as measured by the SGRQ, a reduction in respiratory-related and all cause hospital admissions, and improvement in dyspnoea as measured by the (m)MRC. No statistically significant differences were found in other outcome parameters. However, heterogeneity among interventions, study populations, follow-up time and outcome measures makes it difficult to formulate clear recommendations regarding the most effective form and content of self management in COPD.

Search for neutral MSSM Higgs bosons at LEP

Abstract: The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric standard model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of “benchmark” models, including CP-conserving and CP-violating scenarios. These interpretations lead in all cases to large exclusions in the MSSM parameter space. Absolute limits are set on the parameter cosβ and, in some scenarios, on the masses of neutral Higgs bosons.