Dr Deshi Has Gathered the Results of 52 Studies on Antenatal

Dr. Deshi has gathered the results of 52 studies on antenatal (during pregnancy) and subsequent postpartum depression to learn whether antenatal depression is a significant risk factor for postpartum depression. To most efficiently combine the results of all 52 studies in a way that allows her to easily see how strongly the two problems are related, she should use a

A) correlation coefficient
B) case study
C) modal design
D) meta-analysis
E) pooled experimental design