In reply

We thank Dr Lavelle for his interest in our work and the comments he provided regarding our recent publication. Clearly, scientific inquiry has its basis in molecular and biochemical analyses, clinical trials, and health services research, as well as in statistical analyses. Each methodology provides unique information from which our knowledge base arises. The purpose of this meta-analysis is not to review the molecular advances of the field of oral carcinogenesis. In contrast, it provides a systematic and quantitative approach to combining data from several clinical investigations that address the same question. Although some people do not like meta-analysis, this analytic approach helps to resolve uncertainties that remain from the results of individual trials and is of particular interest in oncology because it can help us summarize the evidence by using statistical techniques that pool data from multiple disparate studies to yield a single result and permit accurate quantification and detection of small to moderate effects among a large group of subjects. In addition, meta-analysis can point out deficiencies in the study design of past and current studies, suggest the need for new studies, and inform researchers about the size and design of these studies. They are limited by the fact that meta-analysis can not improve the quality or reporting of the original studies, nor can it control for publication bias.