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Meta-analysis
Kinds of Meta-analysis Terms modified by Meta-analysis Selected AbstractsConflict resolution education and antisocial behavior in U.S. schools: A meta-analysisCONFLICT RESOLUTION QUARTERLY, Issue 1 2007Wendy M. Garrard This meta-analysis examines more than twenty-five years of evidence to determine whether participation in school-based conflict resolution education (CRE) contributes to reduced antisocial behaviors among youth in kindergarten through twelfth grade in U.S. schools. Evidence from thirty-six studies, representing 4,971 students, shows improvements in antisocial behaviors in CRE participants compared to control groups (Effect Size = .26), with larger effects observed during midadolescence ( ES = .53) and early adolescence ( ES = .22) compared to middle childhood ( ES = .06). Improvements in antisocial behavior outcomes attributable to CRE are significant in both practical and statistical terms and are similar for different CRE program approaches. [source] Phylogenetic Comparative Methods Strengthen Evidence for Reduced Genetic Diversity among Endangered TetrapodsCONSERVATION BIOLOGY, Issue 5 2010PATRICK A. FLIGHT evolución de la historia de vida; extinción; heterocigosidad de proteínas; regresión filogenética; tamaño poblacional efectivo Abstract:,The fitness of species with little genetic diversity is expected to be affected by inbreeding and an inability to respond to environmental change. Conservation theory suggests that endangered species will generally demonstrate lower genetic diversity than taxa that are not threatened. This hypothesis has been challenged because the time frame of anthropogenic extinction may be too fast to expect genetic factors to significantly contribute. I conducted a meta-analysis to examine how genetic diversity in 894 tetrapods correlates with extinction threat level. Because species are not evolutionarily independent, I used a phylogenetic regression framework to address this issue. Mean genetic diversity of tetrapods, as assessed by protein heterozygosity, was 29.7,31.5% lower on average in threatened species than in their nonthreatened relatives, a highly significant reduction. Within amphibians as diversity decreased extinction risk increased in phylogenetic models, but not in nonphylogenetic regressions. The effects of threatened status on diversity also remained significant after accounting for body size in mammals. These results support the hypothesis that genetic effects on population fitness are important in the extinction process. Resumen:,Se espera que la adaptabilidad de una especie con poca diversidad genética sea afectada por la endogamia y una incapacidad para responder a cambios ambientales. La teoría de la conservación sugiere que las especies en peligro generalmente muestran menor diversidad genética que taxa que no están amenazados. Esta hipótesis ha sido cuestionada porque el período de tiempo de la extinción antropogénica puede ser muy rápido para esperar que los factores genéticos contribuyan significativamente. Realice un meta-análisis para examinar cómo se correlaciona la diversidad genética de 894 tetrápodos con el nivel de amenaza de extinción. Debido a que las especies no son independientes evolutivamente, utilice un marco de regresión filogenética para abordar este tema. La media de la diversidad genética de tetrápodos, medida como la heterocigosidad de proteínas, fue 29.7,31.5% menor en las especies amenazadas que en sus parientes no amenazados, una reducción altamente significativa. En anfibios, a medida que disminuía la diversidad el riesgo de extinción incrementaba en los modelos filogenéticos, pero no en las regresiones no filogenéticas. El efecto del estatus de amenaza sobre la biodiversidad también permaneció significativo después de considerar el tamaño corporal de mamíferos. Estos resultados dan soporte a la hipótesis de que los efectos genéticos sobre la adaptabilidad de la población son importantes en el proceso de extinción. [source] Susceptibility of Common and Rare Plant Species to the Genetic Consequences of Habitat FragmentationCONSERVATION BIOLOGY, Issue 3 2007OLIVIER HONNAY diversidad genética; endogamia; fragmentación de hábitat; sistema reproductivo; tamaño poblacional Abstract:,Small plant populations are more prone to extinction due to the loss of genetic variation through random genetic drift, increased selfing, and mating among related individuals. To date, most researchers dealing with genetic erosion in fragmented plant populations have focused on threatened or rare species. We raise the question whether common plant species are as susceptible to habitat fragmentation as rare species. We conducted a formal meta-analysis of habitat fragmentation studies that reported both population size and population genetic diversity. We estimated the overall weighted mean and variance of the correlation coefficients among four different measures of genetic diversity and plant population size. We then tested whether rarity, mating system, and plant longevity are potential moderators of the relationship between population size and genetic diversity. Mean gene diversity, percent polymorphic loci, and allelic richness across studies were positively and highly significantly correlated with population size, whereas no significant relationship was found between population size and the inbreeding coefficient. Genetic diversity of self-compatible species was less affected by decreasing population size than that of obligate outcrossing and self-compatible but mainly outcrossing species. Longevity did not affect the population genetic response to fragmentation. Our most important finding, however, was that common species were as, or more, susceptible to the population genetic consequences of habitat fragmentation than rare species, even when historically or naturally rare species were excluded from the analysis. These results are dramatic in that many more plant species than previously assumed may be vulnerable to genetic erosion and loss of genetic diversity as a result of ongoing fragmentation processes. This implies that many fragmented habitats have become unable to support plant populations that are large enough to maintain a mutation-drift balance and that occupied habitat fragments have become too isolated to allow sufficient gene flow to enable replenishment of lost alleles. Resumen:,Las poblaciones pequeñas de plantas son más propensas a la extinción debido a la pérdida de variación genética por medio de la deriva génica aleatoria, el incremento de autogamia y la reproducción entre individuos emparentados. A la fecha, la mayoría de los investigadores que trabajan con erosión genética en poblaciones fragmentadas de plantas se han enfocado en las especies amenazadas o raras. Cuestionamos si las especies de plantas comunes son tan susceptibles a la fragmentación del hábitat como las especies raras. Realizamos un meta análisis formal de estudios de fragmentación que reportaron tanto tamaño poblacional como diversidad genética. Estimamos la media general ponderada y la varianza de los coeficientes de correlación entre cuatro medidas de diversidad genética y de tamaño poblacional de las plantas. Posteriormente probamos si la rareza, el sistema reproductivo y la longevidad de la planta son moderadores potenciales de la relación entre el tamaño poblacional y la diversidad genética. La diversidad genética promedio, el porcentaje de loci polimórficos y la riqueza alélica en los estudios tuvieron una correlación positiva y altamente significativa con el tamaño poblacional, mientras que no encontramos relación significativa entre el tamaño poblacional y el coeficiente de endogamia. La diversidad genética de especies auto compatibles fue menos afectada por la reducción en el tamaño poblacional que la de especies exogámicas obligadas y especies auto compatibles, pero principalmente exogámicas. La longevidad no afectó la respuesta genética de la población a la fragmentación. Sin embargo, nuestro hallazgo más importante fue que las especies comunes fueron tan, o más, susceptibles a las consecuencias genéticas de la fragmentación del hábitat que las especies raras, aun cuando las especies histórica o naturalmente raras fueron excluidas del análisis. Estos resultados son dramáticos porque muchas especies más pueden ser vulnerables a la erosión genética y a la pérdida de diversidad genética como consecuencia de los procesos de fragmentación que lo se asumía previamente. Esto implica que muchos hábitats fragmentados han perdido la capacidad para soportar poblaciones de plantas lo suficientemente grandes para mantener un equilibrio mutación-deriva y que los fragmentos de hábitat ocupados están tan aislados que el flujo génico es insuficiente para permitir la reposición de alelos perdidos. [source] Enhancement of Farmland Biodiversity within Set-Aside LandCONSERVATION BIOLOGY, Issue 4 2004JOSH VAN BUSKIRK agricultura; biodiversidad; conservación; terrenos de reserva Abstract:,The efficacy of agricultural set-aside policies for protecting farmland biodiversity is widely debated. Based on a meta-analysis of 127 published studies, we found that land withdrawn from conventional production unequivocally enhances biodiversity in North America and Europe. The number of species of birds, insects, spiders, and plants is 1,1.5 standard deviation units higher on set-aside land, and population densities increase by 0.5,1 standard deviation units. Set-aside land may be especially beneficial for desirable taxa because North American bird species that have exhibited population declines react most positively to set-aside agricultural land. Larger and older plots protect more species and higher densities, and set-aside land is more effective in countries with less-intensive agricultural practices and higher fractions of land removed from production. Although policies specifically designed to protect biodiversity might work even better, current incentives clearly improve the standing of plants and animals in farmland. Resumen:,La eficiencia de las políticas de reservas agrícolas para la protección de la biodiversidad en tierras cultivadas esta ámpliamente debatida. Con base en un meta-análisis de 127 estudios publicados, encontramos que terrenos retirados de la producción convencional inequívocamente mejoran la biodiversidad en Norte América y Europa. El número de especies de aves, insectos, arañas y plantas es 1-1.5 unidades de desviación estándar más alto en terrenos de reserva, y las densidades de población incrementan en 0.5-1 unidades de desviación estándar. Los terrenos de reserva pueden ser especialmente benéficos para taxones deseables porque especies de aves norteamericanas que han presentado una declinación poblacional reaccionan positivamente a terrenos agrícolas de reserva. Parcelas más grandes y viejas protegen a más especies y tienen mayores densidades, y los terrenos de reserva son más efectivos en países con prácticas agrícolas menos intensivas y con mayores fracciones de tierras removidas de la producción. Aunque las políticas diseñadas específicamente para proteger la biodiversidad pueden ser mejores aún, los incentivos actuales claramente mejoran la situación de plantas y animales en tierras agrícolas. [source] Corporate Boards and Company Performance: review of research in light of recent reformsCORPORATE GOVERNANCE, Issue 5 2007David Finegold Recent US corporate governance reforms introduced extensive regulations and guidelines for public corporations, particularly corporate boards. This article evaluates the extent to which empirical research on corporate boards and firm performance supports these reforms. Building on the meta-analysis conducted by Zahra and Pearce (1989), we review 105 studies published between 1989 and 2005. We find most of the practices mandated by the Sarbanes-Oxley Act of 2002, and the regulations issued by the New York Stock Exchange (NYSE) and the NASDAQ, had not been subject to prior study. Where board characteristics have been studied, we find limited guidance for policymakers on identifying governance practices that result in more effective firm performance. In an effort to increase the relevance of future research on boards and firm performance, we provide a framework on corporate boards. [source] Trials update in walesCYTOPATHOLOGY, Issue 2007A. Fiander Three ongoing studies will be presented and discussed. Prevalence of Human Papillomavirus Infection in a South Wales Screening population Methods: A total of 10 000 consecutive, anonymous liquid based cytology screening samples were collected over a five month period in 2004. Age, cytology result and social deprivation score was provided for each specimen. The methodology was chosen to ensure inclusion of all women attending routine cervical screening, avoiding potential constraints associated with obtaining individual informed consent. The liquid based cytology samples were processed and reported by the receiving cytology laboratory and the residual specimens sent to the HPV Research Laboratory, Wales College of Medicine, where they were processed and stored at -80°C until analysis. High risk and low risk HPV Typing was undertaken using PCR , EIA (Jacobs et al 1997). Full high risk typing was performed on HPV positive specimens. Results: The study population had a mean age of 38 years with 92% negative, 5% borderline and 3% dyskaryotic cytology. The average social deprivation score was 17.4 (based upon the Welsh Index of multiple deprivation). The following results will be presented: HPV prevalence by age. HPV prevalence by cytology result. Type specific HPV prevalence in single and multiple infection. Conclusion: This study represents the largest type specific HPV Prevalence Study in the UK to date. As such it will form a useful base line against which to access performance of marketed HPV tests and evaluating the impact following implementation of HPV vaccination. [Funded by Welsh Office for Research and Development] CRISP , 1 Study (Cervical Randomized Intervention Study Protocol -1) Background: Indole-3-carbinol (I3C) and Diindolylmethane (DIM) are found in cruciferous vegetables and have been identified as compounds that could potentially prevent or halt carcinogenesis. I3C spontaneously forms DIM in vivo during acid digestion. I3C has been shown to prevent the development of cervical cancer in HPV 16 transgenic mice and both I3C and DIM have been shown to promote cell death in cervical cancer cell models. DIM is the major active bi-product of I3C and preliminary data indicate that DIM is active in cervical dysplasia and may be better tolerated than I3C. Aim: To investigate chemoprevention of high grade cervical neoplasia using Diindolylmethane (DIM) supplementation in women with low grade cytological abnormalities on cervical cytology. Objectives: To observe any reduction in the prevalence of histological proven high-grade cervical intraepithelial neoplasia (CIN) after 6 months of supplementation. ,,To observe any reduction in the prevalence of cytological abnormalities. ,,To observe any changes in the clinical appearance of the cervix. To assess acceptability and monitor any side effects of DIM supplementation. ,,To assess whether any benefit is seen in relation to Human Papillomavirus (HPV) status including HPV Type, Viral load and integration. Methods: This is a double blind randomized placebo-controlled trial involving 600,700 women with low grade cytological abnormalities on a cervical smear. Randomization is in the ratio of 2 : 1 in favour of active medication. Women with first mildly dyskaryotic smear or second borderline smear are eligible. They are asked to take two capsules daily for 6 months. At the end of 6 months they undergo repeat cervical cytology, HPV testing and colposcopy. Results: A progress report will be given for this ongoing study. [Funded: - Cancer Research UK] Type Specific HPV Infection in Welsh Cervical Cancers Background: Whilst there have been numerous studies of HPV infection associated with cervical cancer and on prevalence of Human Papillomavirus in diverse populations there have been no studies of these variables in the same population. Against a background of prophylactic HPV vaccination it is important to assess potential protection against cervical cancer within a given population. The most comprehensive analysis of HPV type specific cervical cancer is a meta-analysis published by the IARC in 2003. This however included only three UK based studies, totalling 118 cases, 75 of which were only investigated by HPV type PCR for four high risk types. None of this data was presented with associated population based prevalence data. Therefore, the research objectives for this study in combination with the first study above, are as follows: To determine the frequency of specific HPV types in cervical cancers in Wales. To compare the distribution of specific HPV types amongst cervical cancers with their prevalence in the general population. This will allow accurate delineation of the relationship between prevalence of specific HPV types in the general population and their association with clinically relevant disease. This information is a pre-requisite to assess the potential impact of prophylactic vaccination against HPV infection in Wales. Methods: Welsh Cervical Cancer specimens from 2000,2005 will be identified from pathology departments within Wales. The pathology of each tumour will be reviewed by a single Gynaecological Pathologist. The age of the patient and pathological features of the tumour will be noted. DNA will be extracted from the paraffin sections and HPV typed by PCR-EIA. Results: A progress report will be given for this ongoing study. [Funded by Welsh Office for Research and Development] [source] An evidence-based assessment of the clinical guidelines for replanted avulsed teeth.DENTAL TRAUMATOLOGY, Issue 2 2009Part II: prescription of systemic antibiotics The principles of evidence-based dentistry can be used to assess whether this is the best approach based on currently-available evidence. The objective of this study was to use the principles of evidence-based dentistry to answer the PICO question: (P) for a replanted avulsed permanent tooth, (I) is prescribing SAT, (C) compared with not prescribing SAT, (O) associated with an increased likelihood of successful periodontal healing after tooth replantation? Materials and methods:, A literature search was performed across four internet databases (Ovid Medline, Cochrane Library, PubMed, ISI Web of Science), for relevant citations (n = 35 702). Limiting citations to those in English and removing duplicates produced a set of titles (n = 14 742) that were sieved according to evidence-based dentistry principles. Relevant titles were selected for abstract assessment (n = 782), identifying papers for examination (n = 74). Inclusion criteria were applied and three papers (326 total teeth) met the final criteria for meta-analysis. Results:, Meta-analyses found no statistically significant difference between prescribing or not prescribing antibiotics for acceptable periodontal healing without progressive root resorption (common odds ratio = 0.90, SE = 0.29, 95% confidence intervals = 0.51,1.58). Conclusion:, The evidence for an association between prescribing SAT and an increased likelihood of acceptable periodontal healing outcome is inconclusive. This investigation of antibiotic use as defined in the clinical guidelines indicates there is inconclusive clinical evidence from studies of replanted avulsed human teeth to either contradict or support the guideline. Pending future research to the contrary, dentists are recommended to follow current guidelines in prescribing SAT when replanting avulsed teeth. [source] Mania associated with antidepressant treatment: comprehensive meta-analytic reviewACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2010L. Tondo Tondo L, Vázquez G, Baldessarini RJ. Mania associated with antidepressant treatment: comprehensive meta-analytic review. Objective:, To review available data pertaining to risk of mania,hypomania among bipolar (BPD) and major depressive disorder (MDD) patients with vs. without exposure to antidepressant drugs (ADs) and consider effects of mood stabilizers. Method:, Computerized searching yielded 73 reports (109 trials, 114 521 adult patients); 35 were suitable for random effects meta-analysis, and multivariate-regression modeling included all available trials to test for effects of trial design, AD type, and mood-stabilizer use. Results:, The overall risk of mania with/without ADs averaged 12.5%/7.5%. The AD-associated mania was more frequent in BPD than MDD patients, but increased more in MDD cases. Tricyclic antidepressants were riskier than serotonin-reuptake inhibitors (SRIs); data for other types of ADs were inconclusive. Mood stabilizers had minor effects probably confounded by their preferential use in mania-prone patients. Conclusion:, Use of ADs in adults with BPD or MDD was highly prevalent and moderately increased the risk of mania overall, with little protection by mood stabilizers. [source] The contribution of active medication to combined treatments of psychotherapy and pharmacotherapy for adult depression: a meta-analysisACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2010P. Cuijpers Cuijpers P, van Straten A, Hollon SD, Andersson G. The contribution of active medication to combined treatments of psychotherapy and pharmacotherapy for adult depression: a meta-analysis. Objective:, Although there is sufficient evidence that combined treatments of psychotherapy and pharmacotherapy are more effective for depression in adults than each of the treatments alone, it remains unclear what the exact contribution of active medication is to the overall effects of combined treatments. This paper examines the contribution of active medication to combined psychotherapy and pharmacotherapy treatments. Method:, Meta-analysis of randomised controlled trials comparing the combination of psychotherapy and pharmacotherapy with the combination of psychotherapy and placebo. Results:, Sixteen identified studies involving 852 patients met our inclusion criteria. The standardised mean difference indicating the differences between the combination of psychotherapy and pharmacotherapy and the combination of psychotherapy and placebo was 0.25 (95% CI: 0.03,0.46), which corresponds to a numbers-needed-to-be-treated of 7.14. No significant differences between subgroups of studies were found. Conclusion:, Active medication has a small but significant contribution to the overall efficacy of combined treatments. [source] No evidence for switching the antidepressant: systematic review and meta-analysis of RCTs of a common therapeutic strategyACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2010T. Bschor Bschor T, Baethge C. No evidence for switching the antidepressant: systematic review and meta-analysis of RCTs of a common therapeutic strategy. Objective:, Switching antidepressants is a common strategy for managing treatment-resistant depressed patients. However, no systematic reviews have been conducted to date. Method:, We systematically searched MEDLINE/EMBASE/Cochrane Central Register of Controlled Trials and additional sources. We included double-blind studies of patients with depressive symptomatology who were not responding to initial antidepressant monotherapy and were subsequently randomized to another antidepressant or to continue the same antidepressant. Results were pooled for meta-analysis of response + remission rates using a fixed-effects model. Results:, A total of three studies were included. Switching to another antidepressant was not superior to continuing the initial antidepressant in any of these studies. Our meta-analysis showed no significant advantages to either strategy and no significant heterogeneity of results [OR for response rates: 0.85 (95% CI: 0.55,1.30) favoring continuing]. Conclusion:, There is a discrepancy between the published evidence and the frequent decision to switch antidepressants, indicating an urgent need for more controlled studies. Pending such studies we recommend that physicians rely on more thoroughly evaluated strategies. [source] The current status of urban-rural differences in psychiatric disordersACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2010J. Peen Peen J, Schoevers RA, Beekman AT, Dekker J. The current status of urban,rural differences in psychiatric disorders. Objective:, Reviews of urban,rural differences in psychiatric disorders conclude that urban rates may be marginally higher and, specifically, somewhat higher for depression. However, pooled results are not available. Method:, A meta-analysis of urban,rural differences in prevalence was conducted on data taken from 20 population survey studies published since 1985. Pooled urban,rural odds ratios (OR) were calculated for the total prevalence of psychiatric disorders, and specifically for mood, anxiety and substance use disorders. Results:, Significant pooled urban,rural OR were found for the total prevalence of psychiatric disorders, and for mood disorders and anxiety disorders. No significant association with urbanization was found for substance use disorders. Adjustment for various confounders had a limited impact on the urban,rural OR. Conclusion:, Urbanization may be taken into account in the allocation of mental health services. [source] Cutaneous melanoma: interferon alpha adjuvant therapy for patients at high risk for recurrent diseaseDERMATOLOGIC THERAPY, Issue 1 2006Marko Lens ABSTRACT:, Systemic adjuvant therapy in melanoma patients is the systemic treatment that is administered with the goal of eradicating micrometastatic deposits in patients who are clinically free of disease after surgical removal of the primary melanoma, but with a high risk of systemic recurrence. Interferon-alpha (IFN-,) is one of the most frequently used adjuvant therapies. Several randomized trials evaluated the efficacy of IFN-, in melanoma patients. However, results from conducted trials are controversial. Twelve randomized IFN-, trials are discussed in detail. All trials, including meta-analysis, failed to demonstrate a clear impact of IFN-, therapy on overall survival in melanoma patients. Based on currently available evidence, IFN-, therapy in the adjuvant setting should not be considered standard of care for patients who have melanoma. Results from ongoing studies are awaited. Further research for this therapy is required. [source] Prevalence of alcohol use disorders in schizophrenia , a systematic review and meta-analysisACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2009J. Koskinen Objective:, Our aim was to present recent studies of alcohol use disorders (AUDs) in patients with schizophrenia, estimate overall prevalence and characteristics affecting the prevalence of AUDs. Method:, We conducted a search using three literature databases and a manual search on articles published in 1996,2008. Meta-regression was used to study how prevalence is affected by different study characteristics. Articles that reported diagnoses according to DSM or ICD diagnostic systems were included. Results:, Altogether 60 studies met our criteria. The median of current AUD prevalence was 9.4% (inter-quartile range, IQR 4.6,19.0, 18 studies) and median of lifetime AUD prevalence 20.6% (IQR 12.0,34.5, 47 studies). In studies using DSM-III-R median prevalence was higher than that in studies using DSM-IV, ICD-9 or ICD-10 (32/17/11/6%). Conclusion:, Approximately every fifth patient with schizophrenia had lifetime AUD diagnosis. When contrasted with the most recent review, there might be a descending trend in AUD prevalence in patients with schizophrenia. [source] Augmentation of clozapine with a second antipsychotic , a meta-analysis of randomized, placebo-controlled studiesACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2009D. M. Taylor Objective:, Inadequate response to clozapine treatment is frequently encountered in practice and augmentation strategies have been developed in an attempt to improve response. Aims of the study were to evaluate the therapeutic effect of adding an antipsychotic drug to clozapine treatment. Method:, Meta-analysis of randomized, placebo-controlled studies of antipsychotic augmentation of clozapine treatment. Results:, Ten studies (including 522 subjects) met inclusion criteria. Antipsychotic augmentation showed significant benefit over the addition of placebo on only one outcome measure examined [mean effect size for rating scale score (BPRS/PANSS) ,0.180, 95% CI ,0.356 to ,0.004]. Antipsychotic augmentation showed no advantage on withdrawals from trials (risk ratio 1.261, 95% CI 0.679,2.345) or on CGI scores (effect size ,0.661, 95% CI ,1.475 to 0.151). Duration of study was not associated with outcome (P = 0.95). There was no evidence of publication bias. Conclusion:, In studies lasting up to 16 weeks, the addition of an antipsychotic to clozapine treatment has marginal therapeutic benefit. Longer and larger trials are necessary to demonstrate the precise therapeutic utility of antipsychotic co-therapy with clozapine. [source] How to read and understand and use systematic reviews and meta-analysesACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2009S. Leucht Objective,: Systematic reviews and meta-analyses are increasingly frequently used in the evaluation of medical treatments. This review explains the principles of the methodology, significance and limitations of systematic reviews. Method:, Short review article. Results:, In contrast to conventional reviews, systematic reviews use a structured approach in retrieving, analyzing and interpreting the evidence. A comprehensive search strategy is applied to identify all relevant trials. Study selection and data extraction is performed independently by at least two reviewers. The data are usually synthesized in a meta-analysis applying statistical methods to examine homogeneity. Funnel plots and other statistical methods are applied to detect publication bias. Conclusion:, Due to the enormous amount of scientific information published every year, systematic reviews and meta-analyses have become indispensable methods for the evaluation of medical treatments. [source] Valid electrodermal hyporeactivity for depressive suicidal propensity offers links to cognitive theoryACTA PSYCHIATRICA SCANDINAVICA, Issue 5 2009L.-H. Thorell Objective:, Studies from three independent laboratories report varying relationships between electrodermal hyporeactivity and suicidal behavior in depressed patients. The aims of this study were to explain that variation, to assess the discriminative validity of electrodermal hyporeactivity for suicide and suicide attempts and to suggest a tentative explanation model. Method:, A meta-analysis was performed of 279 depressed patients and 59 healthy subjects. Results:, The sensitivity was 96.6% and specificity 92.9% of electrodermal hyporeactivity for suicide and 83.3% and 92.7%, respectively, for suicide and/or violent attempts. The shares of hyporeactives were strongly significantly and greatly larger in high than in low suicidal propensity groups, P- value ranging from 4.7 × 10,8 to 1.1 × 10,14. Conclusion:, The high discriminative validity and the emerging links over a proposed interest-limiting precognitive set to cognitive theory of suicide encourage clinical application of tests of electrodermal reactivity. The study offers a series of testable hypotheses constituting a new platform for suicidological research in depression. [source] Rate of progression of mild cognitive impairment to dementia , meta-analysis of 41 robust inception cohort studiesACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2009A. J. Mitchell Objective:, To quantify the risk of developing dementia in those with mild cognitive impairment (MCI). Method:, Meta-analysis of inception cohort studies. Results:, Forty-one robust cohort studies were identified. To avoid heterogeneity clinical studies, population studies and clinical trials were analysed separately. Using Mayo defined MCI at baseline and adjusting for sample size, the cumulative proportion who progressed to dementia, to Alzheimer's disease (AD) and to vascular dementia (VaD) was 39.2%, 33.6% and 6.2%, respectively in specialist settings and 21.9%, 28.9% and 5.2%, respectively in population studies. The adjusted annual conversion rate (ACR) from Mayo defined MCI to dementia, AD and VaD was 9.6%, 8.1% and 1.9%, respectively in specialist clinical settings and 4.9%, 6.8% and 1.6% in community studies. Figures from non-Mayo defined MCI and clinical trials are also reported. Conclusion:, The ACR is approximately 5,10% and most people with MCI will not progress to dementia even after 10 years of follow-up. [source] Systematic review of chorioamnionitis and cerebral palsyDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 1 2002Yvonne W. Wu Abstract In a recent meta-analysis evaluating the relationship between chorioamnionitis and cerebral palsy, we found that chorioamnionitis is a risk factor for both cerebral palsy and cystic periventricular leukomalacia (cPVL). The current paper extends the meta-analysis by including studies published in the year 2000, and by further evaluating the causes of heterogeneity among individual study results. Using a random effects model, clinical chorioamnionitis was significantly associated with both cerebral palsy (RR 1.9, 95% CI 1.5,2.5) and cPVL (RR 2.6, 95% CI 1.7,3.9). Sources of heterogeneity included widely varying practices in the diagnosis of clinical chorioamnionitis, different gestational age characteristics, and varying study year. We conclude that based on the available literature, chorioamnionitis is a risk factor for both cerebral palsy and cPVL. MRDD Research Reviews 2002;8:25,29. © 2002 Wiley-Liss, Inc. [source] Group cognitive behavioural therapy for obsessive,compulsive disorder: a systematic review and meta-analysisACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2009H. Jónsson Objective:, Behaviour therapy with exposure and response prevention (ERP) or cognitive behavioural therapy (CBT) including ERP are considered the psychological treatments of choice for obsessive,compulsive disorder (OCD), but group CBT/ERP has received relatively little research attention in the treatment of OCD. The aim of this study was to provide a meta-analysis of the effectiveness of group CBT/ERP for OCD. Method:, A systematic literature search was conducted and studies were meta-analysed by means of the Cochrane Review Manager Program with measures of i) pre- to post-effect sizes (ES) and ii) between-group ES in comparison with different control conditions. Outcome was primarily measured on the Y-BOCS and ES was calculated in the form of Cohens d. Results:, Thirteen trials were included in the meta-analysis. The overall pre,post-ES of these trials of 1.18 and a between-group ES of 1.12 compared with waiting list control in three randomized controlled studies indicate that group CBT/ERP is an effective treatment for OCD. Group CBT achieved better results than pharmacological treatment in two studies. One study found no significant differences between individual and group CBT. Conclusion:, Group CBT is an effective treatment for OCD, but more studies are needed to compare the effectiveness of group and individual treatment formats. [source] Consistency of immigrant and country-of-birth suicide rates: a meta-analysisACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2008M. Voracek Objective:, Multifaceted evidence (family, twin, adoption, molecular genetic, geographic and surname studies of suicide) suggests genetic risk factors for suicide. Migrant studies are also informative in this context, but underused. In particular, a meta-analysis of the associations of immigrant (IMM) and country-of-birth (COB) suicide rates is unavailable. Method:, Thirty-three studies, reporting IMM suicide rates for nearly 50 nationalities in seven host countries (Australia, Austria, Canada, England, the Netherlands, Sweden and the USA), were retrieved. Results:, Total-population IMM and COB suicide rates were strongly positively associated (combined rank-order correlation across 20 eligible studies: 0.65, 95% CI: 0.56,0.73, P < 10,9). The effect generalized across both sexes, host countries and study periods. Conclusion:, Following the logic of the migrant study design of genetic epidemiology, the correspondence of IMM and COB suicide rates is consistent with the assumption of population differences in the prevalence of genetic risk factors for suicide. [source] Quantified superiority of cognitive behaviour therapy to antidepressant drugs: a challenge to an earlier meta-analysisACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2008G. B. Parker Objective:, The study aimed to review the conclusion of a previously published meta-analysis which quantified distinct superiority of cognitive therapy to antidepressant drug-therapy (P < 0.0001). Method:, We sought to include all studies used in the original meta-analysis. Adopting both that study's inclusion criteria and additional criteria resulted in a reduced set of studies. We analysed both ,completer' and ,intention to treat' data, using effect size and odds ratio quantification. Results:, There was an overall trend for cognitive therapy to be superior to antidepressant drug-therapy, but this was significant for only one of the four meta-analyses (an intention to treat analysis). We demonstrated considerable heterogeneity between studies, and a significantly higher drop-out rate in the antidepressant groups. Conclusion:, The previous interpretation , cognitive therapy being distinctly superior to antidepressant medication , cannot be sustained from the currently analysed data set. [source] Cognitive-behavioural therapy for late-life anxiety disorders: a systematic review and meta-analysisACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2008G. J. Hendriks Objective:, To examine and estimate the efficacy of cognitive-behavioural therapy (CBT) for late-life anxiety disorders. Method:, A systematic review and meta-analysis of randomized controlled trials comparing CBT with i) a waiting-list control condition and ii) an active control condition controlling for non-specific effects in patients aged over 60 years and suffering from an anxiety disorder. The main outcome parameter of individual studies, i.e. effect on anxiety, was pooled using the standardized mean difference (SMD). Results:, Seven papers fulfilled the inclusion criteria, including nine randomized controlled comparisons for 297 patients. Anxiety symptoms were significantly more reduced following CBT than after either a waiting-list control condition [SMD = ,0.44 (95 CI: ,0.84 ,0.04), P = 0.03] or an active control condition [SMD = ,0.51 (95 CI: ,0.81, ,0.21), P<0.001]. Additionally, CBT significantly alleviated accompanying symptoms of worrying and depression. Conclusion:, Cognitive-behavioural therapy is efficacious for the treatment of late-life anxiety disorders. [source] Cancer incidence in patients with schizophrenia and their first-degree relatives , a meta-analysisACTA PSYCHIATRICA SCANDINAVICA, Issue 5 2008V. S. Catts Objective:, Controversy concerning cancer incidence in schizophrenia exists because of heterogeneous study findings. Method:, A meta-analysis was performed on standardized incidence ratios (SIR) of cancer in patients with schizophrenia and first-degree relatives and compared with general population samples. Results:, The pooled overall cancer incidence in patients was not significantly increased (SIR = 1.05, CI 0.95,1.15). Lung cancer incidence was slightly increased (SIR = 1.31, CI 1.01,1.71), but was reduced after adjusting for smoking prevalence. The incidence of several cancers unrelated to smoking was reduced in patients. Breast cancer rates were significantly increased in female patients. The pooled overall cancer incidence in siblings (SIR = 0.89, CI 0.84,0.94) and parents (SIR = 0.90, CI 0.88,0.93) was significantly reduced. A meta-regression detected a significant relationship between cancer risk in the general population and relative risk in patients. Conclusion:, The meta-analysis aided exploration of inconsistent study findings. There is a discrepancy between cancer risk exposure and cancer incidence in schizophrenia consistent with a protective effect. [source] Has repetitive transcranial magnetic stimulation (rTMS) treatment for depression improved?ACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2007A systematic review, meta-analysis comparing the recent vs. the earlier rTMS studies Objective:, To investigate whether the recent repetitive transcranial magnetic stimulation (rTMS) studies on depression using new parameters of stimulation have shown improved clinical results. Method:, We performed a systematic review and a meta-analysis of the rTMS studies on depression published in the past 12 months comparing these results with an earlier meta-analysis that analyzed the results of the initial rTMS studies on depression. Results:, Using our inclusion criteria, we selected the meta-analysis of Martin [Br J Psychiatry (2003) Vol. 182, 480,491] that included 13 studies (324 patients) and five studies for the recent meta-analysis (274 patients). The pooled effect size (standardized mean difference between pretreatment vs. post-treatment) from the random effects model was ,0.76 (95% confidence interval, CI, ,1.01 to ,0.51). This result was significantly larger than that of the earlier meta-analysis (,0.35, 95% CI ,0.66 to ,0.04). Conclusion:, Our findings suggest that recent rTMS clinical trials have shown larger antidepressant effects when compared with the earlier studies. [source] Cognitive training in Alzheimer's disease: a meta-analysis of the literatureACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2006D. I. Sitzer Objective:, To systematically review the literature and summarize the effect of cognitive training (CT) for Alzheimer's disease (AD) patients on multiple functional domains. Method:, Effect sizes (Cohen's d) were calculated for 17 controlled studies identified through a comprehensive literature review. Results:, An overall effect size of 0.47 was observed for all CT strategies across all measured outcomes. Mean effect sizes were higher for restorative (0.54) than for compensatory (0.36) strategies. Domain-specific effect sizes ranged from 2.16 (verbal and visual learning) to ,0.38 (visuospatial functioning). Data are also presented on the relative impact of restorative and compensatory strategies for each domain of functioning. Conclusion:, CT evidenced promise in the treatment of AD, with primarily medium effect sizes for learning, memory, executive functioning, activities of daily living, general cognitive problems, depression, and self-rated general functioning. Restorative strategies demonstrated the greatest overall effect on functioning. Several limitations of the published literature are discussed. [source] Rediscovering bile acid sequestrantsDIABETES OBESITY & METABOLISM, Issue 12 2009D. S. H. Bell Aim: In the recently published The Justification for the Use of statins in Primary prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) mega-trial, rosuvastatin significantly reduced cardiovascular events at the expense of a small but significant increase in the risk of developing type 2 diabetes. The increased risk of new-onset diabetes was in keeping with a recent meta-analysis which suggested that statins, with the possible exception of pravastatin, marginally increase the risk of developing type 2 diabetes. Methods: Although the net effect of rosuvastatin was obviously very positive, we hypothesized that the addition of a bile aid sequestrant to a statin would not only further decrease lipid levels and potentially further decrease cardiovascular events but also protect against the development of diabetes. This is particularly relevant because the bile acid sequestrant, colesevelam, has recently been approved for therapy of diabetes. Results: Colesevelam like other bile acid sequestrants lowers low-density lipoprotein levels by 16% and C-reactive protein by 22% beyond the reductions that occur with statin therapy alone. Bile acid sequestrants confer lipid-lowering, glucose-lowering, and anti-inflammatory benefits, and have been shown to reduce risk of cardiovascular events. Conclusions: Therefore, colesevelam should be the most effective and logical agent to add to a statin in the diabetic and insulin-resistant patient, because in addition to lowering cardiac risk it may prevent the development of diabetes, as well as improving glycaemic control in the established diabetic patient. [source] Long-acting insulin analogues vs.DIABETES OBESITY & METABOLISM, Issue 4 2009NPH human insulin in type 1 diabetes. Aim:, Basal insulin in type 1 diabetes can be provided using either NPH (Neutral Protamine Hagedorn) human insulin or long-acting insulin analogues, which are supposed to warrant a better metabolic control with reduced hypoglycaemic risk. Aim of this meta-analysis is the assessment of differences with respect to HbA1c (Glycated hemoglobin), incidence of hypoglycaemia, and weight gain, between NPH human insulin and each long-acting analogue. Methods:, Of 285 randomized controlled trials with a duration > 12 weeks comparing long-acting insulin analogues (detemir or glargine) with NPH insulin in type 1 diabetic patients identified through Medline search and searches on www.clinicaltrials.gov, 20 met eligibility criteria (enrolling 3693 and 2485 in the long-acting analogues and NPH group respectively). Data on HbA1c and body mass index at endpoint, and incidence of any, nocturnal and severe hypoglycaemia, were extracted and meta-analysed. Results:, Long-acting analogues had a small, but significant effect on HbA1c [-0.07 (,0.13; ,0.01)%; p = 0.026], in comparison with NPH human insulin. When analysing the effect of long-acting analogues on body weight, detemir was associated with a significantly smaller weight gain than human insulin [by 0.26 (0.06;0.47) kg/m2; p = 0.012]. Long-acting analogues were associated with a reduced risk for nocturnal and severe hypoglycaemia [OR (Odd Ratio, 95% Confidence Intervals) 0.69 (0.55; 0.86), and OR 0.73 (0.60; 0.89) respectively; all p < 0.01]. Conclusions:, The switch from NPH to long-acting analogues as basal insulin replacement in type 1 diabetic patients had a small effect on HbA1c, and also reduced the risk of nocturnal and severe hypoglycaemia. [source] The effect of thiazolidinediones on adiponectin serum level: a meta-analysisDIABETES OBESITY & METABOLISM, Issue 5 2008N. Riera-Guardia Background and aims:, Adiponectin is a hormone mainly produced by white adipose tissue. Decreased levels of adiponectin are linked with visceral obesity, insulin resistance states, and cardiovascular diseases. Recently, several studies have pointed out an increase in adiponectin serum levels in subjects undergoing treatment with thiazolidinediones (TZD). The aim of this study is to systematically review the current state of evidence of the effect of TZD on adiponectin serum level with special attention to avoid publication bias. Materials and methods:, An extensive literature search was performed. Meta Analysis Version 2.0 computer program was used to calculate statistical differences in means and 95% confidence interval (CI). Publication bias was assessed using different statistical approaches. Results:, In the meta-analysis including 19 studies the overall standardized mean difference was 0.94 (95% CI, 0.81,1.06) which means that subjects treated with TZDs on average had means of adiponectin concentration that were about 1 standard deviation higher than the comparison groups even after controlling for possible biases. Conclusions:, The results obtained agree with a moderate increase of serum adiponectin. The results clearly reveal an increase of endogenous serum adiponectin levels by intake of TZDs and may point to a potential new option to manage obesity-related diseases. [source] Hypofrontality in schizophrenia: a meta-analysis of functional imaging studiesACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2004K. Hill Objective:, Hypofrontality is not a well-replicated finding in schizophrenia either at rest or under conditions of task activation. Method:, Studies comparing whole brain and frontal blood flow/metabolism in schizophrenic patients and normal controls were pooled. Voxel-based studies were also combined to examine the pattern of prefrontal activation in schizophrenia. Results:, Whole brain flow/metabolism was reduced in schizophrenia to only a small extent. Resting and activation frontal flow/metabolism were both reduced with a medium effect size. Duration of illness significantly moderated resting hypofrontality, but the moderating effects of neuroleptic treatment were consistent with an influence on global flow/metabolism only. Pooling of voxel-based studies did not suggest an abnormal pattern of activation in schizophrenia. Conclusion:, Meta-analysis supports resting hypofrontality in schizophrenia. Task-activated hypofrontality is also supported, but there is little from voxel-based studies to suggest that this is associated with an altered pattern of regional functional architecture. [source] Long-term outcome of pediatric obsessive,compulsive disorder: a meta-analysis and qualitative review of the literatureACTA PSYCHIATRICA SCANDINAVICA, Issue 1 2004S. E. Stewart Objective:, To review the extant literature on the long-term outcome of child/adolescent-onset obsessive,compulsive disorder (OCD). Method:, Medline and Psychlit databases were systematically searched for articles regarding long-term outcomes of child/adolescent-onset OCD. Meta-analysis regression was applied to evaluate predictors and persistence of OCD. Results:, Sixteen study samples (n = 6,132; total = 521 participants) in 22 studies had follow-up periods ranging between 1 and 15.6 years. Pooled mean persistence rates were 41% for full OCD and 60% for full or subthreshold OCD. Earlier age of OCD onset (z = ,3.26, P = 0.001), increased OCD duration (z = 2.22, P = 0.027) and in-patient vs. out-patient status (z = 2.94, P = 0.003) predicted greater persistence. Comorbid psychiatric illness and poor initial treatment response were poor prognostic factors. Although psychosocial function was frequently compromised, most studies lacked comprehensive outcome measures. Conclusion:, Long-term persistence of pediatric OCD may be lower than believed. Future studies should include broader measures of outcome including symptomatic persistence and functional impairment in multiple domains. [source] | ||||||||||||||||||||||||||||||||||||||||||||||