Meta-analysis of binary outcomes via generalized linear mixed models: a simulation study

Background: Systematic reviews and meta-analyses of binary outcomes are widespread in all areas of application. The odds ratio, in particular, is by far the most popular effect measure. However, the standard meta-analysis of odds ratios using a random-effects model has a number of potential problems. An attractive alternative approach for the meta-analysis of binary outcomes uses a class of generalized linear mixed models (GLMMs). GLMMs are believed to overcome the problems of the standard random-effects model because they use a correct binomial-normal likelihood. However, this belief is based on theoretical considerations, and no sufficient simulations have assessed the performance of GLMMs in meta-analysis. This gap may be due to the computational complexity of these models and the resulting considerable time requirements. Methods: The present study is the first to provide extensive simulations on the performance of four GLMM methods (models with fixed and random study effects and two conditional methods) for meta-analysis of odds ratios in comparison to the standard random effects model. Results: In our simulations, the hypergeometric-normal model provided less biased estimation of the heterogeneity variance than the standard random-effects meta-analysis using the restricted maximum likelihood (REML) estimation when the data were sparse, but the REML method performed similarly for the point estimation of the odds ratio, and better for the interval estimation. Conclusions: It is difficult to recommend the use of GLMMs in the practice of meta-analysis. The problem of finding uniformly good methods of the meta-analysis for binary outcomes is still open

The case for the introduction of new chemotherapy agents in the treatment of advanced non small cell lung cancer in the wake of the findings of The National Institute of Clinical Excellence (NICE)

After years of nihilism towards the use of chemotherapy for non small cell lung cancer in the UK it would appear that we have now reached the point where the use of chemotherapy to relieve symptoms, maintain quality of life, and prolong life, are now accepted for informed patients with good performance status willing to accept short-term toxicities. The use of the new agents vinorelbine, gemcitabine and paclitaxel in combination with cisplatin or carboplatin are all active regimens which offer small but real advantages over standard UK triple therapies (MVP, MIC) in terms of resource use, toxicity profiles and response rates. Overall survival could be increased by as much as 10% at one year on indirect comparisons. The use of docetaxel as second line therapy now offers lung cancer patients a second bite of the cherry, and should overall also prolong survival. It is only in embracing these small gains that we can currently make progress in the treatment of NSCLC