For example, if I have 3 different trials each for 3 different drugs and I used meta analysis (sub group analysis) to generate effect sizes. How can I interpret the effect sizes? All drugs are being compared to placebo e.g.
Drug A - 3 RCTs - pooled odds ratio 1.5 Drug B - 3 RCTs - pooled odds ratio 1.7 Drug C - 3 RCTs - pooled odds ratio 3
I am aware of network meta analysis but I was suggested to avoid this as it’s not necessary for my project. I am able to make simple indirect comparisons as long as I state the limitations.
Firstly, would I be able to say, drug C had the greater effect compared to placebo (at a particular outcome) so can be considered the better of the three drugs, though head to head trials are necessary to confirm this.
What are the general limitations of this method?
I have tried to ensure the studies I have used are as similar in the design as possible. All comparing to a common comparator, placebo.
Also should I make comments on the heterogeneity between the 3 studies used for each drug.
Also should I do this using a random or fixed effects model?