Lack of bias in the meta-analysis of recombinant versus urinary follicle stimulating hormone

In a meta-analysis of randomized trials comparing recombinant and urinary F SH for ovarian stimulation in infertility treatment cycles, the clinical pr egnancy rate per cycle started was significantly higher with recombinant FS H. Before the results of the different trials can be pooled, it is importan t to determine whether the results are homogeneous so that one can obtain a n overall treatment estimate that is without bias. There are several method s to ascertain lack of homogeneity, including logistic regression analysis, sensitivity analysis comparing fixed-effect and random-effect models, test ing based in the chi (2) distribution, and graphical methods comparing even t rates in experimental and treatment groups. These methods all confirmed t hat the treatment effect was homogeneous across all trials thereby providin g assurance that the overall conclusion of the superior efficacy of recombi nant FSH compared with urinary FSH is based on an unbiased analysis.