Introducing Prospective Meta-analysis to the Medical Literature

www.smso.net

IntroductionMeta-analysis is a statistical analysis which combines or integrates the results of several independent clinical trials considered by the analyst to be 'combinable (Huque MF,1988 ).

www.smso.net

IntroductionMeta-analysis can help gynecologists keep abreast of the medical literature by summarising large bodies of evidence and helping to explain differences among studies on the same topic

www.smso.net

What is a Prospective Meta-Analysis? A prospective meta-analysis is a meta-analysis where studies (usually RCTs) are identified, evaluated and determined to be eligible before the results of any of the studies become known.

www.smso.net

Why PMA?PMA can therefore help to overcome some of the problems of retrospective meta-analyses by enabling: hypotheses to be specified a priori ignorant of the results of individual trials

www.smso.net

Prospective application of selection criteria A priori statements of intended analyses, including sub-group analyses, to be made before the Results of individual trials are known.

www.smso.net

GnRH antagonists Model

www.smso.net

BackgroundGnRH antagonists have emerged as another alternative in ART. They are claimed to result in an immediate arrest of gonadotrophin secretion and so the duration of treatment can be reduced as well as the number of ampoules of hMG.

www.smso.net

Objectives We wished to determine the role of GnRH antagonists in controlled ovarian hyperstimulation.

www.smso.net

Patient PopulationInfertile couple under assisted reproductive program using GnRH antagonists in the protocol of ovulation induction. The following characteristics of the participants will be considered.

www.smso.net

1. Infertile couple (explained and unexplained infertility)2. Have achieved ovarian hyperstimulation (confirmed by number of follicles seen by ultrasound or estradiol assay) 3. Had controlled ovarian hyperstimulation for any assisted reproductive technique

www.smso.net

Outcome MeasuresPrimary outcomes:-Number of oocyte retrieved per cycleSuccess rate (pregnancy /woman , pregnancy/cycle) as determined by serum B-HCG and ultrasound examination for fetal heart.

www.smso.net

Secondary outcomesIncidence of ovarian hyperstimulation syndrome Number of cycle cancellationCost benefit

www.smso.net

DesignMeta-analysis of all randomised controlled trials that will report the use of Gonadotrophin releasing hormone (GnRH) antagonists verses GnRH agonists in assisted reproduction.

www.smso.net

Search strategy 1-The Cochrane MDSG specialised register of controlled trials2-MEDLINE database 3-EMBASE database 4-Handsearching the references mentioned in the obtained studies and reviews.

www.smso.net

Interventions Method of ovarian hyperstimulation.Method of GnRH antagonists and agonists administration: timing, route, duration and doseNumber of ampoules of gonadotrophin

www.smso.net

ResultsData will be independently extracted by the two reviewers and any discrepancies will be resolved by discussion. When needed the reviewers will write to the authors and the pharmaceutical companies and try to get hold of extra information and the raw data.

www.smso.net

Heterogeneity between the results of different studies will be examined by inspecting the scatter in the data points and the overlap in their confidence intervals and more formally by checking results of chi-square tests. Where possible the outcomes will be pooled statistically.

www.smso.net

StatisticsThe dichotomous data results for each study will be expressed as an odds ratio with 95% confidence intervals. These results will be combined for meta-analysis with RevMan software (using the Peto-modified Mantel-Haenszel method).

www.smso.net

ConclusionGnRH antagonists meta-analysis can be considered the first prospective meta-analysis not only in the field of reproductive medicine but in the entire field of gynecology

www.smso.net

ConclusionThe results of this systematic review will be published in the Cochrane Library soon.

www.smso.net