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Previous Meta-analyses (previous + meta-analyse)
Selected AbstractsEffects of pulp and paper mill effluent on fish: A temporal assessment of fish health across sampling cyclesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2010Timothy J. Barrett Abstract The Canadian environmental effects monitoring (EEM) program is a regulated, cyclical, industry-funded program designed to determine whether receiving water impacts exist when a mill is in compliance with its discharge limits. The results from three cycles of the fish monitoring program (1992 to 2004) are available from over 200 surveys of fish compared between sites located upstream and downstream of pulp and paper mill effluent outfalls. Previous meta-analyses have shown a national average response pattern across cycles characterized by an increase in endpoints measuring energy storage and growth and a decrease in a reproductive endpoint, consistent with a response of nutrient enrichment in combination with some form of metabolic disruption. Although the national average pattern of effects was temporally consistent, there was some variability in the magnitude of effects among cycles. Questions were raised as to whether the intercycle variability was due to changes in effluent quality or due, at least in part, to other factors. The present study compares responses over the first three cycles, and shows that the choice of sentinel species is likely to be a major contributing factor to the variability in observed effects. Subset analyses using studies from mills that used the same sentinel species across cycles reveal fairly uniform responses and little evidence of significant improvements in overall fish health from cycles one to three. However, a meta-analysis using 1991 data collected from 10 mills before the implementation of the EEM program and data from the same mills collected during cycles one to three of the program reveal significantly reduced effects on relative liver weight and potential improvements in other endpoints. Environ. Toxicol. Chem. 2010;29:440,452. © 2009 SETAC [source] Effectiveness of cutaneous warming systems on temperature control: meta-analysisJOURNAL OF ADVANCED NURSING, Issue 6 2010Cristina Maria Galvão galvão c.m., liang y. & clark a.m. (2010) Effectiveness of cutaneous warming systems on temperature control: meta-analysis. Journal of Advanced Nursing,66(6), 1196,1206. Abstract Title.,Effectiveness of cutaneous warming systems on temperature control: meta-analysis. Aim., This paper is a report of a meta-analysis to identify the effectiveness of different types of cutaneous warming systems in temperature control for patients undergoing elective surgery. Background., Hypothermia is a common and serious complication of surgery. Different cutaneous warming systems are used to prevent hypothermia during surgery but there have been no previous meta-analyses of the effectiveness of different warming systems in controlling temperature. Data sources., We conducted a search of the CINAHL (2000 to April 2009), Medline (2000 to April 2009), Embase (2000 to April 2009) and the Cochrane Register of Controlled Trials (2000 to April 2009) databases for randomized controlled trials published in English, Spanish and Portuguese. The primary outcome measure of interest was core body temperature. Methods., A systematic review incorporating meta-analysis was carried out. Results., From 329 papers, 23 trials compared warming systems. Forced-air warming systems had a strong tendency towards superior temperature control over passive insulation via cotton blankets (mean difference: 0·29°C; 95% confidence interval: ,0·02 to 0·59, three trials 292 patients) and radiant warming systems (mean difference: 0·16°C; 95% confidence interval: ,0·01 to 0·33, three trials, 161 patients). However, circulating water garments tended to be more effective than forced-air warming systems (mean difference: ,0·73°C; 95% confidence interval: ,1·51 to 0·05, I2 = 97%; four trials, 198 patients). Pooled results approached statistical significance and indicated clinically meaningful differences in temperature control. Conclusion., Current evidence suggests that circulating water garments offer better temperature control than forced-air warming systems, and both are more effective than passive warming devices. [source] The Effectiveness of Corrective Feedback in SLA: A Meta-AnalysisLANGUAGE LEARNING, Issue 2 2010Shaofeng Li This study reports on a meta-analysis on the effectiveness of corrective feedback in second language acquisition. By establishing a different set of inclusion/exclusion criteria than previous meta-analyses and performing a series of methodological moves, it is intended to be an update and complement to previous meta-analyses. Altogether 33 primary studies were retrieved, including 22 published studies and 11 Ph.D. dissertations. These studies were coded for 17 substantive and methodological features, 14 of which were identified as independent and moderator variables. It was found that (a) there was a medium overall effect for corrective feedback and the effect was maintained over time, (b) the effect of implicit feedback was better maintained than that of explicit feedback, (c) published studies did not show larger effects than dissertations, (d) lab-based studies showed a larger effect than classroom-based studies, (e) shorter treatments generated a larger effect size than longer treatments, and (f) studies conducted in foreign language contexts produced larger effect sizes than those in second language contexts. Possible explanations for the results were sought through data cross-tabulation and with reference to the theoretical constructs of SLA. [source] REVISITING INTERVIEW,COGNITIVE ABILITY RELATIONSHIPS: ATTENDING TO SPECIFIC RANGE RESTRICTION MECHANISMS IN META-ANALYSISPERSONNEL PSYCHOLOGY, Issue 4 2007CHRISTOPHER M. BERRY This study revisits the relationship between interviews and cognitive ability tests, finding lower magnitudes of correlation than have previous meta-analyses; a finding that has implications for both the construct and incremental validity of the interview. Our lower estimates of this relationship than previous meta-analyses were mainly due to (a) an updated set of studies, (b) exclusion of samples in which interviewers potentially had access to applicants' cognitive test scores, and (c) attention to specific range restriction mechanisms that allowed us to identify a sizable subset of studies for which range restriction could be accurately accounted. Moderator analysis results were similar to previous meta-analyses, but magnitudes of correlation were generally lower than in previous meta-analyses. Findings have implications for the construct and incremental validity of interviews, and meta-analytic methodology in general. [source] THE INCREMENTAL VALIDITY OF INTERVIEW SCORES OVER AND ABOVE COGNITIVE ABILITY AND CONSCIENTIOUSNESS SCORESPERSONNEL PSYCHOLOGY, Issue 2 2000JOSE M. CORTINA Recent research has suggested that scores on measures of cognitive ability, measures of Conscientiousness, and interview scores are positively correlated with job performance. There remains, however, a question of incremental validity: To what extent do interviews predict above and beyond cognitive ability and Conscientiousness? This question was addressed in this paper by (a) conducting meta-analyses of the relationships among cognitive ability, Conscientiousness, and interviews, (b) combining these results with predictive validity results from previous meta-analyses to form a "meta-correlation matrix" representing the relationships among cognitive ability, Conscientiousness, interviews, and job performance, and (c) performing 9 hierarchical regressions to examine the incremental validity of 3 levels of structured interviews in best, actual, and worst case scenarios for prediction. Results suggested that interview scores contribute to the prediction of job performance over and above cognitive ability and Conscientiousness to the extent that they are structured, with scores from highly structured interviews contributing substantially to prediction. Directions for future research are discussed. [source] Gray matter, white matter, brain, and intracranial volumes in first-episode bipolar disorder: a meta-analysis of magnetic resonance imaging studiesBIPOLAR DISORDERS, Issue 8 2009Antonio Vita Objectives:, To perform a comprehensive quantitative analysis of the existing magnetic resonance imaging (MRI) studies of the brain conducted on patients with first-episode bipolar disorder (BD). Methods:, A systematic search was performed of MRI studies that reported quantitative measurements of brain volumes of first-episode bipolar patients and healthy controls. Four meta-analyses were performed for four cerebral regions. Results:, Significant overall effect sizes were demonstrated, with a reduction detected in patients with BD for total intracranial and white matter volumes, but not for gray matter and whole brain volumes. Conclusions:, The available MRI literature indicates that specific structural brain abnormalities are already present in first-episode bipolar patients. These do not overlap with those emerging from previous meta-analyses performed in patients with chronic BD. These findings support the hypothesis of different patterns of changes in brain morphology over the time course of bipolar disorder. [source] | ||||||||||