Advances in meta-analysis as a research method

Meta-analysis is a method of data analysis applied to summarizing research findings, both quantitative and qualitative summaries of individual studies. Rooted in the fundamental values of the scientific enterprise of replicability, causal and correlational analysis, it is useful for answering three general questions: What is the central tendency or typical study outcome? How much variability exists among study outcomes? What is the explanation of the variability? Advanced statistical and mathematical techniques are being used in counting studies with significant and non-significant findings; in combining effect size estimates based on fixed- or random-effects models; in the use of general linear models; and, Bayesian procedures. The methodology of meta-analysis and suggestions for publications are presented as well as appropriate software programs available for use in the meta-analytic process are explored. The benefits of meta-analysis as a research method in effecting health policy development is offered as a pragmatic perspective for future consideration. Conclusions have implications for the use of meta-analysis as a teaching strategy and as a methodology in nursing research and other applied sciences. In view of the rapid pace of knowledge development and increased public demand for accountability, meta-analysis offers an opportunity for organizing phenomena which gives direction for provision of quality health care.