Mortimer Duncan, French Simon
Health Technology Assessment, Institute of Health Services Research, Monash University, Melbourne, Australia.
J Assist Reprod Genet. 2006 Jan;23(1):33-6. doi: 10.1007/s10815-005-9004-2.
To determine whether between-trial heterogeneity in relative risk of fertilisation for intracytoplasmic sperm injection (ICSI) compared to in vitro fertilisation (IVF) can be explained by learning or by between-trial variation in patient characteristics.
Systematic review and meta-analysis of trials comparing fertilisation outcomes for ICSI and IVF (without surgical sperm retrieval). Meta-regressions to identify associations between treatment effect and trial characteristics.
Coefficients on individually significant covariates from the meta-regressions confirm that the ICSI versus IVF treatment effect is increased when patients are "unsuited for IVF" but reduced as semen quality improves and when IVF insemination concentrations are increased. However, the relative risk of fertilisation varies inversely with publication date; contrary to the hypothesised learning effect.
While it is recognised that publication date might proxy for unobserved covariates, the possibility of a learning effect in favour of ICSI is not supported by the meta-regression.
确定与体外受精（IVF）相比，卵胞浆内单精子注射（ICSI）受精相对风险的试验间异质性能否通过学习效应或患者特征的试验间差异来解释。
对比较ICSI和IVF（不进行手术取精）受精结果的试验进行系统评价和荟萃分析。进行荟萃回归以确定治疗效果与试验特征之间的关联。
荟萃回归中各个显著协变量的系数证实，当患者“不适合IVF”时，ICSI与IVF的治疗效果会增加，但随着精液质量的改善以及IVF授精浓度的增加而降低。然而，受精的相对风险与发表日期呈反比；这与假设的学习效应相反。
虽然人们认识到发表日期可能代表未观察到的协变量，但荟萃回归并不支持有利于ICSI的学习效应的可能性。
