Combining evidence in nursing research - Methods and implications

Background. The knowledge explosion in health care coupled with recent evidence-based practice initiatives has increased both the need for and the production of reviews of past research. The proliferation of such reviews has contributed to inconsistency in methods and terminology. Differing methods for integrative reviews, systematic reviews, meta-analyses, and qualitative reviews have been proposed, yet are not clearly differentiated in published reports. Although there are common features to these methods, each method has a distinct purpose, sampling frame, definition, and type of analysis. Approach: The literature on research review methods was analyzed and synthesized. Specific attention was directed toward the issues specific to combining primary nursing research studies. Results: The defining characteristics of different research review methods, the common stages of all research reviews, and criteria for evaluating quality are described. Discussion: Greater clarity regarding research review methods has the potential to enhance methodological rigor and subsequently the applicability of findings of all review methods to practice and policy.