Question

Please help me identify what the quantitative research design is for the following study. There are four main types of Quantitative research: 1. Descriptive 2. Co relational 3. Causal-Comparative/Quasi-Experimental 4. Experimental Research.

Given the significant disability, morbidity and mortality associated with depression, the promising recent trials of ketamine highlight a novel intervention. A meta-analysis was conducted to assess the efficacy of ketamine in comparison with placebo for the reduction of depressive symptoms in patients who meet criteria for a major depressive episode.
Method: Two electronic databases were searched in September 2013 for English-language studies that were ran-domized placebo-controlled trials of ketamine treatment for patients with major depressive disorder or bipolar depression and utilized a standardized rating scale. Studies including participants receiving electroconvulsive ther-apy and adolescent/child participants were excluded. Five studies were included in the quantitative meta-analysis. Results: The quantitative meta-analysis showed that ketamine significantly reduced depressive symptoms. The overall effect size at day 1 was large and statistically significant with an overall standardized mean difference of 1.01 (95% confidence interval 0.69–1.34) (Pb.001), with the effects sustained at 7 days postinfusion. The heteroge-neity of the studies was low and not statistically significant, and the funnel plot showed no publication bias. Conclusions: The large and statistically significant effect of ketamine on depressive symptoms supports a promising, new and effective pharmacotherapy with rapid onset, high efficacy, and good tolerability.

Answer 1

Given study is an example of Descriptive quantitative study, as the researcher is observing and describing the behaviour or intervention of ketamin without influencing it in any way, with the help of meta analysis or previously studied results.

Meta analysis is a statistical technique for summarizing previous quantitative research.

In co relational study relationship is identified, there is one group but two or more variables are compared

In Quasi experimental study cause and effect relationship is identified, with only one variable but 2 or more groups. It is said quasi experimental and not experimental because either randomisation or manipulation or control group is missing

On the other hand in experimental study all three are present

a) Randomisation (samples are randomly selected)

b) Manipulation( some intervention is done)

c) Control group