Systematic reviews are an umbrella term for a number of different review designs, all with specific goals (e.g., identify scope of available research or gaps, reduce bias, statistically combine and analyze results from multiple studies). They differ from basic literature review articles that qualitatively summarize the literature on a topic and do not necessarily have inclusion or exclusion criteria.

Epidemiological meta-analyses are quantitative types of systematic reviews, in which summary measures of exposure–outcome associations are calculated based on the results of a selection of existing studies. In other words, a meta-analysis statistically combines the results from multiple studies, with the goal of calculating more precise measures, increasing sample size, or reducing bias in the combined results. The goal of meta-analysis is to obtain a more robust understanding of the relationship between an exposure and a health outcome than could be obtained from a single study. While meta-analyses are considered to be strong research designs because of their formal, statistical characteristics, they are not without weakness or critics. For instance, existing studies included in a meta-analysis may have strengths and limitations of their own.

For this Discussion, you examine the validity and strengths and limitations of systematic reviews and meta-analyses in epidemiological research.

To prepare:

• Review the studies and articles provided in the Learning Resources. Consider the strengths and limitations of systematic reviews and meta-analyses. Make sure you are clear on the difference between the two approaches.

By Day 3 of Week 8

Post a brief summary of your informed opinion regarding the validity of the use of systematic reviews and meta-analyses in epidemiological research. Include at least two strengths or limitations of each technique. Provide evidence from at least one of the articles in the Learning Resources to support and justify your position.