824 resultados para effect size
Resumo:
The first genome-wide association study for BMI identified a polymorphism, rs7566605, 10 kb upstream of the insulin-induced gene 2 (INSIG2) transcription start site, as the most significantly associated variant in children and adults. Subsequent studies, however, showed inconsistent association of this polymorphism with obesity traits. This polymorphism has been hypothesized to alter INSIG2 expression leading to inhibition of fatty acid and cholesterol synthesis. Hence, we investigated the association of the INSIG2 rs7566605 polymorphism with obesity- and lipid-related traits in Danish and Estonian children (930 boys and 1,073 girls) from the European Youth Heart Study (EYHS), a school-based, cross-sectional study of pre- and early pubertal children. The association between the polymorphism and obesity traits was tested using additive and recessive models adjusted for age, age-group, gender, maturity and country. Interactions were tested by including the interaction terms in the model. Despite having sufficient power (98%) to detect the previously reported effect size for association with BMI, we did not find significant effects of rs7566605 on BMI (additive, P = 0.68; recessive, P = 0.24). Accordingly, the polymorphism was not associated with overweight (P = 0.87) or obesity (P = 0.34). We also did not find association with waist circumference (WC), sum of four skinfolds, or with total cholesterol, triglycerides, low-density lipoprotein, or high-density lipoprotein. There were no gender-specific (P = 0.55), age-group-specific (P = 0.63) or country-specific (P = 0.56) effects. There was also no evidence of interaction between genotype and physical activity (P = 0.95). Despite an adequately powered study, our findings suggest that rs7566605 is not associated with obesity-related traits and lipids in the EYHS.
Resumo:
Choices not only reflect our preference, but they also affect our behavior. The phenomenon of choice-induced preference change has been of interest to cognitive dissonance researchers in social psychology, and more recently, it has attracted the attention of researchers in economics and neuroscience. Preference modulation after the mere act of making a choice has been repeatedly demonstrated over the last 50 years by an experimental paradigm called the “free-choice paradigm.” However, Chen and Risen (2010) pointed out a serious methodological flaw in this paradigm, arguing that evidence for choice-induced preference change is still insufficient. Despite the flaw, studies using the traditional free-choice paradigm continue to be published without addressing the criticism. Here, aiming to draw more attention to this issue, we briefly explain the methodological problem, and then describe simple simulation studies that illustrate how the free-choice paradigm produces a systematic pattern of preference change consistent with cognitive dissonance, even without any change in true preference. Our stimulation also shows how a different level of noise in each phase of the free-choice paradigm independently contributes to the magnitude of artificial preference change. Furthermore, we review ways of addressing the critique and provide a meta-analysis to show the effect size of choice-induced preference change after addressing the critique. Finally, we review and discuss, based on the results of the stimulation studies, how the criticism affects our interpretation of past findings generated from the free-choice paradigm. We conclude that the use of the conventional free-choice paradigm should be avoided in future research and the validity of past findings from studies using this paradigm should be empirically re-established. (PsycINFO Database Record (c) 2013 APA, all rights reserved)(journal abstract)
Resumo:
There are now many reports of imaging experiments with small cohorts of typical participants that precede large-scale, often multicentre studies of psychiatric and neurological disorders. Data from these calibration experiments are sufficient to make estimates of statistical power and predictions of sample size and minimum observable effect sizes. In this technical note, we suggest how previously reported voxel-based power calculations can support decision making in the design, execution and analysis of cross-sectional multicentre imaging studies. The choice of MRI acquisition sequence, distribution of recruitment across acquisition centres, and changes to the registration method applied during data analysis are considered as examples. The consequences of modification are explored in quantitative terms by assessing the impact on sample size for a fixed effect size and detectable effect size for a fixed sample size. The calibration experiment dataset used for illustration was a precursor to the now complete Medical Research Council Autism Imaging Multicentre Study (MRC-AIMS). Validation of the voxel-based power calculations is made by comparing the predicted values from the calibration experiment with those observed in MRC-AIMS. The effect of non-linear mappings during image registration to a standard stereotactic space on the prediction is explored with reference to the amount of local deformation. In summary, power calculations offer a validated, quantitative means of making informed choices on important factors that influence the outcome of studies that consume significant resources.
Resumo:
Various studies have indicated a relationship between enteric methane (CH4) production and milk fatty acid (FA) profiles of dairy cattle. However, the number of studies investigating such a relationship is limited and the direct relationships reported are mainly obtained by variation in CH4 production and milk FA concentration induced by dietary lipid supplements. The aim of this study was to perform a meta-analysis to quantify relationships between CH4 yield (per unit of feed and unit of milk) and milk FA profile in dairy cattle and to develop equations to predict CH4 yield based on milk FA profile of cows fed a wide variety of diets. Data from 8 experiments encompassing 30 different dietary treatments and 146 observations were included. Yield of CH4 measured in these experiments was 21.5 ± 2.46 g/kg of dry matter intake (DMI) and 13.9 ± 2.30 g/ kg of fat- and protein-corrected milk (FPCM). Correlation coefficients were chosen as effect size of the relationship between CH4 yield and individual milk FA concentration (g/100 g of FA). Average true correlation coefficients were estimated by a random-effects model. Milk FA concentrations of C6:0, C8:0, C10:0, C16:0, and C16:0-iso were significantly or tended to be positively related to CH4 yield per unit of feed. Concentrations of trans-6+7+8+9 C18:1, trans-10+11 C18:1, cis- 11 C18:1, cis-12 C18:1, cis-13 C18:1, trans-16+cis-14 C18:1, and cis-9,12 C18:2 in milk fat were significantly or tended to be negatively related to CH4 yield per unit of feed. Milk FA concentrations of C10:0, C12:0, C14:0-iso, C14:0, cis-9 C14:1, C15:0, and C16:0 were significantly or tended to be positively related to CH4 yield per unit of milk. Concentrations of C4:0, C18:0, trans-10+11 C18:1, cis-9 C18:1, cis-11 C18:1, and cis- 9,12 C18:2 in milk fat were significantly or tended to be negatively related to CH4 yield per unit of milk. Mixed model multiple regression and a stepwise selection procedure of milk FA based on the Bayesian information criterion to predict CH4 yield with milk FA as input (g/100 g of FA) resulted in the following prediction equations: CH4 (g/kg of DMI) = 23.39 + 9.74 × C16:0- iso – 1.06 × trans-10+11 C18:1 – 1.75 × cis-9,12 C18:2 (R2 = 0.54), and CH4 (g/kg of FPCM) = 21.13 – 1.38 × C4:0 + 8.53 × C16:0-iso – 0.22 × cis-9 C18:1 – 0.59 × trans-10+11 C18:1 (R2 = 0.47). This indicated that milk FA profile has a moderate potential for predicting CH4 yield per unit of feed and a slightly lower potential for predicting CH4 yield per unit of milk. Key words: methane , milk fatty acid profile , metaanalysis , dairy cattle
Resumo:
Background Anorexia Nervosa (AN) is a highly life-threatening disorder that is extremely difficult to treat. There is evidence that family-based therapies are effective for adolescent AN, but no treatment has been proven to be clearly effective for adult AN. The methodological challenges associated with studying the disorder have resulted in recommendations that new treatments undergo preliminary testing prior to being evaluated in a randomized clinical trial. The aim of this study was to provide preliminary evidence on the effectiveness of a treatment program based on a novel adaptation of Dialectical Behavior Therapy (DBT) for adult Anorexia Nervosa (Radically Open-DBT; RO-DBT) that conceptualizes AN as a disorder of overcontrol. Methods Forty-seven individuals diagnosed with Anorexia Nervosa-restrictive type (AN-R; mean admission body mass index = 14.43) received the adapted DBT inpatient program (mean length of treatment = 21.7 weeks). Results Seventy-two percent completed the treatment program demonstrating substantial increases in body mass index (BMI; mean change in BMI = 3.57) corresponding to a large effect size (d = 1.91). Thirty-five percent of treatment completers were in full remission, and an additional 55% were in partial remission resulting in an overall response rate of 90%. These same individuals demonstrated significant and large improvements in eating-disorder related psychopathology symptoms (d = 1.17), eating disorder-related quality of life (d = 1.03), and reductions in psychological distress (d = 1.34). Conclusions RO-DBT was associated with significant improvements in weight gain, reductions in eating disorder symptoms, decreases in eating-disorder related psychopathology and increases in eating disorder-related quality of life in a severely underweight sample. These findings provide preliminary support for RO-DBT in treating AN-R suggesting the importance of further evaluation examining long-term outcomes using randomized controlled trial methodology.
Resumo:
Flavonoids are polyphenolic compounds found in varying concentrations in many plant-based foods. Recent studies suggest that flavonoids can be beneficial to both cognitive and physiological health. Long term flavonoid supplementation over a period of weeks or months has been extensively investigated and reviewed, particularly with respect to cognitive ageing and neurodegenerative disease. Significantly less focus has been directed towards the short term effects of single doses of flavonoids on cognition. Here, we review 21 such studies with particular emphasis on the subclass and dose of flavonoids administered, the cognitive domains affected by flavonoid supplementation, and the effect size of the response. The emerging evidence suggests that flavonoids may be beneficial to attention, working memory, and psychomotor processing speed in a general population. Episodic memory effects are less well defined and may be restricted to child or older adult populations. The evidence also points towards a dose-dependent effect of flavonoids, but the physiological mechanisms of action remain unclear. Overall, there is encouraging evidence that flavonoid supplementation can benefit cognitive outcomes within an acute time frame of 0–6 h. But larger studies, combining cognitive and physiological measures, are needed to strengthen the evidence base.
Resumo:
Background Autism spectrum conditions (ASC) are a group of neurodevelopmental conditions characterized by difficulties in social interaction and communication alongside repetitive and stereotyped behaviours. ASC are heritable, and common genetic variants contribute substantial phenotypic variability. More than 600 genes have been implicated in ASC to date. However, a comprehensive investigation of candidate gene association studies in ASC is lacking. Methods In this study, we systematically reviewed the literature for association studies for 552 genes associated with ASC. We identified 58 common genetic variants in 27 genes that have been investigated in three or more independent cohorts and conducted a meta-analysis for 55 of these variants. We investigated publication bias and sensitivity and performed stratified analyses for a subset of these variants. Results We identified 15 variants nominally significant for the mean effect size, 8 of which had P values below a threshold of significance of 0.01. Of these 15 variants, 11 were re-investigated for effect sizes and significance in the larger Psychiatric Genomics Consortium dataset, and none of them were significant. Effect direction for 8 of the 11 variants were concordant between both the datasets, although the correlation between the effect sizes from the two datasets was poor and non-significant. Conclusions This is the first study to comprehensively examine common variants in candidate genes for ASC through meta-analysis. While for majority of the variants, the total sample size was above 500 cases and 500 controls, the total sample size was not large enough to accurately identify common variants that contribute to the aetiology of ASC.
Resumo:
The aim of this study was to investigate if a telemetry test battery can be used to measure effects of Parkinson’s disease (PD) treatment intervention and disease progression in patients with fluctuations. Sixty-five patients diagnosed with advanced PD were recruited in an open longitudinal 36-month study; 35 treated with levodopa-carbidopa intestinal gel (LCIG) and 30 were candidates for switching from oral PD treatment to LCIG. They utilized a test battery, consisting of self-assessments of symptoms and fine motor tests (tapping and spiral drawings), four times per day in their homes during week-long test periods. The repeated measurements were summarized into an overall test score (OTS) to represent the global condition of the patient during a test period. Clinical assessments included ratings on Unified PD Rating Scale (UPDRS) and 39-item PD Questionnaire (PDQ-39) scales. In LCIG-naïve patients, mean OTS compared to baseline was significantly improved from the first test period on LCIG treatment until month 24. In LCIG-non-naïve patients, there were no significant changes in mean OTS until month 36. The OTS correlated adequately with total UPDRS (rho = 0.59) and total PDQ-39 (0.59). Responsiveness measured as effect size was 0.696 and 0.536 for OTS and UPDRS respectively. The trends of the test scores were similar to the trends of clinical rating scores but dropout rate was high. Correlations between OTS and clinical rating scales were adequate indicating that the test battery contains important elements of the information of well-established scales. The responsiveness and reproducibility were better for OTS than for total UPDRS.
Resumo:
Objetivos: analisar o desenvolvimento neuropsicomotor antes e depois de cirurgia cardíaca em crianças através de dois instrumentos: exame neurológico e do teste de Denver II Métodos: foram randomicamente selecionadas os lactentes com indicação de cirurgia cardíaca com utilização de circulação extra-corpórea no período de abril de 2001 a setembro de 2002 Delineamento: coorte prospectivo não controlado Intervenções: Um dia antes da cirurgia eletiva, na alta da unidade de terapia intensiva pediátrica cardíaca e entre 3 a 6 meses após a cirurgia cardíaca os pacientes incluídos no estudo eram submetidos a um exame neurológico padronizado realizado pelo mesmo neurologista pediátrico e ao teste de Denver II aplicado por 2 pediatras de maneira independente, apresentando uma concordância de resultados entre 89-100% . Estatística: O test t student para amostras pareadas para os índices de Denver II . Teste do Qui-quadrado para as categorias do exame neurológico antes e depois de cirurgia. Foi estimado um tamanho amostral de 15 crianças. Resultados: Foram incluídas 20 crianças, com idade média no momento da correção de 6,7 ± 4,2 meses e peso médio 5,3± 2,2 quilogramas. Os defeitos septais ocorreram em 11 casos (55%). O tempo médio de circulação extra-corpórea era 67± 23,6 minutos, com o uso de ultrafiltração modificada. Quinze crianças tinham atraso no desenvolvimento de neuropsicomotor no momento da cirurgia, mas em seis foi observado normalização depois de 3 a 6 meses de seguimento (p=0,11). Quando os índices de Denver II, dentro de cada domínio, foram analisados (índices motor grosseiro, motor fino, linguagem, total e pessoal-social), observou-se um aumento em todos os domínios após a cirurgia, exceto o último (p < 0.05). O percentual médio de melhora nos índices oscilou entre 17 a 23%. Um tamanho de efeito grande foi calculado para linguagem e moderado nas habilidades de motoras. Conclusão: Apesar destas crianças estarem em risco de novos achados neurológicos, os resultados sugerem uma melhora precoce nos índices de desenvolvimento neuropsicomotor após cirurgia cardíaca com extra-corpórea.
Resumo:
Esta dissertação tem como objetivo identificar, através de um estudo transversal, associações entre as características demográficas, comportamentos de risco sexual e por drogas, sintomatologia psiquiátrica e autoconceito em uma amostra de adolescentes, comparando-os pela soropositividade HIV. Foram entrevistados 388 adolescentes entre 13 e 20 anos que procuraram espontaneamente o Centro de Triagem e Avaliação (CTA) Paulo César Bonfim para realizar o teste anti-HIV. Foram utilizados os questionários CRA (Comportamentos de Risco para AIDS), SCL-90-R (The Symptom Check-List-90-R) e EFA (Escala Fatorial de Autoconceito). A média da idade foi de 17,7 anos (±2,0). A maioria da amostra era do sexo feminino, solteiro ou sem companheiro/a fixo/a, sem trabalho, com baixas escolaridade e renda familiar. Em relação ao teste sorológico, 73% estavam realizandoo pela primeira vez, e a soropositividade geral da amostra foi de 6,2%. A escolaridade foi significativamente mais baixa em soropositivos (OR= 7,8) e não houve diferença estatística entre os grupos nas demais variáveis demográficas. Houve associação direta entre soropositividade e precocidade de início da vida sexual (OR= 3,6), história de gravidez (OR=4,7), prática de aborto prévio (OR= 5,9) e relação sexual com parceiro sem preservativo (OR=3,2). Do total da amostra, 8% dos adolescentes recebeu dinheiro em troca de relação sexual, e isto foi associado à soropositividade (OR=4,5). O mesmo ocorreu nos 13,2% que tiveram relação sexual com paceiro/a possivelmente soropositivo (OR=8,3). Apenas 18,9% da amostra afirmaram usar preservativos nos 6 meses prévios à coleta e 81,4% da amostra não haviam usado preservativo nas relações sexuais ao longo da vida. A prevalência geral de uso de drogas no mês anterior à coleta foi alta, com relato freqüente de uso de múltiplas drogas, sendo as mais freqüentes o álcool (71,6 %), maconha (24,7%), cocaína intranasal (12,4%) e solventes (9,3 %). A soropositividade foi mais alta nos usuários recentes de maconha (OR= 2,8), estimulantes (OR=2,9) e solventes (OR= 7,5). A freqüência a local específico para uso de drogas ocorreu em 22,5% do total da amostra e foi estatisticamente maior nos soropositivos (OR=2,6). Os adolescentes soropositivos apresentaram siginficativamente mais sintomatologia psiquiátrica em todas as dimensões avaliadas. Não houve diferença nas dimensões de autoconceito. O Tamanho de Efeito Padronizado foi maior nas variáveis da sintomatologia psiquiátrica do que nas do autoconceito. Os resultados indicam que os adolescentes estudados ainda não possuem cuidados preventivos suficientes para diminuir o contágio pelo vírus da AIDS. São indivíduos sob risco constante por apresentarem maior freqüência de exposição ao HIV associada à baixa escolaridade, comportamento sexual, uso de drogas e sintomatologia psiquiátrica. A falta de diferenças no autoconceito dos adolescentes soropositivos e soronegativos pode estar associada ao senso de invulnerabilidade próprio da faixa etária. Os achados apontam para a necessidade de programas específicos de prevenção para adolescentes. Medidas de intervenção futuras deverão levar em conta a interação de fatores individuais, ambientais, comportamentais e psicológicos, com o objetivo de implementar mudanças efetivas no comportamento de risco para que se detenha o avanço da epidemia nessa faixa etária.
Resumo:
OBJETIVO: Embora vários modelos de bancada inanimados tenham sido descritos para o treinamento de habilidades de sutura, até o momento, não existe um método ideal para esse ensino e aprendizagem durante a formação médica. O objetivo foi avaliar se a fidelidade dos modelos de bancada interfere na aquisição de habilidades de sutura em estudantes de medicina iniciantes na prática cirúrgica. MÉTODOS: 36 estudantes de medicina sem exposição prévia a habilidades cirúrgicas foram randomizados em três grupos (n = 12): treinamento de suturas baseado em materiais didáticos (controle); treinamento de suturas em modelo de baixa-fidelidade (modelo de bancada de etileno vinil acetato); ou treinamento de suturas em modelo de alta-fidelidade (modelo de bancada de pele de pata de porco). Foram aplicados pré e pós-testes (realização de pontos simples e pontos subdérmicos invertidos em língua de boi). Três ferramentas (Global Rating Scale com avaliação cega, tamanho do efeito e autopercepção da confiança baseada em uma escala de Likert) foram utilizadas para mensurar todas as performances de sutura. RESULTADOS: A análise após o treinamento demonstrou que os estudantes que treinaram nos modelos tiveram um melhor (p < 0.0000) desempenho na avaliação pela Global Rating Scale, quando comparados com o controle, independente da fidelidade do modelo. A magnitude do efeito (treinamento) foi considerada grande (> 0.80) em todas as mensurações. Após o treinamento os alunos sentiram-se mais confiantes (p < 0.0000) para executarem os dois tipos de suturas. CONCLUSÃO: A aquisição de habilidades de suturas no modelo de baixa fidelidade foi semelhante à prática no modelo de alta fidelidade, sendo que a melhora no desempenho dos participantes que treinaram nesses dois modelos foi superior à aprendizagem baseada em materiais didáticos.
Resumo:
Purpose: to compare the efficacy of recombinant LH supplementation for controlled ovarian stimulation in recombinant FSH and GnRH-agonist protocol.Methods: Search strategies included on-line surveys of databases. The fixed effects model was used for odds ratio and effect size (weighted mean difference). Four trials fulfilled the inclusion criteria.Results: a fewer days of stimulation (p < 0.0001), a fewer total amount of r-FSH administered (p < 0.0001) and a higher serum estradiol levels on the day of hCG administration (p < 0.0001) were observed for the r-LH supplementation protocol. However, differences were not observed in number of oocyte retrieved, number of mature oocytes, clinical pregnancy per oocyte retrieval, implantation and miscarriage rates.Conclusions: more randomized controlled trials are necessary before evidence-based recommendations regarding exogenous LH supplementation in ovarian stimulation protocols with FSH and GnRH-agonist for assisted reproduction treatment can be provided.
Resumo:
The aim of the present study was to investigate the potential benefits of cold water immersion (CWI) and active recovery (AR) on blood lactate concentration ([Lac]) and heart rate variability (HRV) indices following high-intensity exercise. 20 male subjects were recruited. on the first visit, an incremental test was performed to determine maximal oxygen consumption and the associated speed (MAS). The remaining 3 visits for the performance of constant velocity exhaustive tests at MAS and different recovery methods (6 min) were separated by 7-day intervals [randomized: CWI, AR or passive recovery (PR)]. The CWI and AR lowered [Lac] (p < 0.05) at 11, 13 and 15 min after exercise cessation in comparison to PR. There was a 'time' and 'recovery mode' interaction for 2 HRV indices: standard deviation of normal R-R intervals (SDNN) (partial eta squared = 0.114) and natural log of low-frequency power density (lnLF) (partial eta squared = 0.090). CWI presented significantly higher SDNN compared to PR at 15 min of recovery (p < 0.05). In addition, greater SDNN values were found in CWI vs. AR during the application of recovery interventions, and at 30 and 75 min post-exercise (p < 0.05 for all differences). The lnLF during the recovery interventions and at 75 min post-exercise was greater using CWI compared with AR (p < 0.05). For square root of the mean of the sum of the squares of differences between adjacent R-R intervals (RMSSD) and natural log of high-frequency power density (lnHF), a moderate effect size was found between CWI and PR during the recovery interventions and at 15 min post-exercise. Our findings show that AR and CWI offer benefits regarding the removal of [Lac] following high-intensity exercise. While limited, CWI results in some improvement in post-exercise cardiac autonomic regulation compared to AR and PR. Further, AR is not recommended if the aim is to accelerate the parasympathetic reactivation.
Resumo:
Objective: This study evaluated the augmentation of venlafaxine with hormone therapy in the treatment of postmenopausal depression. The hormones evaluated were estrogen (0.625 mg) in combination with medroxyprogesterone acetate (2.5 mg) and methyltestosterone (2.5 mg). Design: Seventy-two menopausal women (mean age: 53.6 ± 4.27 years) diagnosed with depression (Montgomery-Åsberg Depression Rating Scale [MADRS] scores ≥ 20) were treated with venlafaxine and one of the following hormone therapy combinations, in a double-blind regimen: estrogen + medroxyprogesterone + methyltestosterone (group 1, n = 20); estrogen + medroxyprogesterone acetate (group 2, n = 20); methyltestosterone only (group 3, n = 16); and no hormone therapy (group 4, n = 16). Study duration was 24 weeks. Primary efficacy outcome was remission according to the MADRS, whereas secondary efficacy measures included the Clinical Global Impression (CGI), Blatt-Kupperman Index, and Women's Health Questionnaire (WHQ). Results: Forty-eight patients completed the study. All groups showed significant improvement from baseline. Group 3 demonstrated significant improvement on the MADRS compared with placebo (group 4) at weeks 20 (P = 0.048) and 24 (P = 0.030); effect size 8.04 (0.83; 15.26) (P = 0.029), but also had the highest dropout rate. Groups 1 and 3 had significant CGI improvement rates compared with placebo: 42.23% (P = 0.012) and 44.45% (P = 0.08), respectively. There were no differences in the WHQ or BKI scores among the groups. Conclusions: Methyltestosterone 2.5 mg had the highest effect size compared with placebo, but the high dropout rate prevented its efficacy from being determined. Estrogen plus medroxyprogesterone, combined with methyltestosterone or otherwise, demonstrated a trend toward increased efficacy of venlafaxine. Further larger-scale clinical trials are needed to elucidate the findings of this pilot study. © 2006 by The North American Menopause Society.
Resumo:
The aim of this meta-analysis was to compare the efficacy of gonadotrophin antagonist (GnRH-ant) versus GnRH agonist (GnRHa) as coadjuvant therapy for ovarian stimulation in poor ovarian responders in IVF/intracytoplasmic sperm injection cycles. Search strategies included on-line surveys of databases such as MEDLINE, EMBASE and others. A fixed effects model was used for odds ratio (OR) and effect size (weighted mean difference, WMD). Six trials fulfilled the inclusion criteria (randomized controlled trials). There was no difference between GnRH-ant and GnRHa (long and flare-up protocols) with respect to cycle cancellation rate, number of mature oocytes and clinical pregnancy rate per cycle initiated, per oocyte retrieval and per embryo transfer. When the mete-analysis was applied to the two trials that had used GnRH-ant versus long protocols of GnRHa, a significantly higher number of retrieved oocytes was observed in the GnRH-ant protocols [P = 0.018; WMD: 1.12 (0.18, 2.05)]. However, when the meta-analysis was applied to the four trials that had used GnRH-ant versus flare-up protocols, a significantly higher number of retrieved oocytes (P = 0.032; WMD: -0.51, 95% CI -0.99, -0.04) was observed in the GnRHa protocols. Nevertheless, additional randomized controlled trials with better planning are needed to confirm these results.