Meta-analysis is a subset of systematic review; a technique for systematically combining pertinent qualitative
and quantitative study data from numerous selected studies to broaden a single conclusion that has more
statistical power. This inference is statistically stronger than the analysis of any single study, due to increase
numbers of topics, greater variety amongst subjects, or collected effects and outcomes. The aim of this review
article is to highlight the definition, history, purpose, characteristics, use, advantage, disadvantage, validity,
and steps in conducting meta-analysis.