Duval and Tweedie’s Trim and Fill method

Duval and Tweedie’s Trim and Fill method

•Uses an iterative procedure to remove most extreme small studies from positive side of funnel plot, re-computing effect size at each iteration until funnel plot is symmetric about new effect size

•Yield an unbiased estimate of effect size

•Trimming also reduces variance of effects, yielding a too narrow C.I.

•Therefore algorithm then adds original studies back into analysis, and imputes a mirror image for each.

•This fill has no impact on point estimate but serves to correct the variance 

the black dots are studies added after the method...

PSM / COMMUNITY MEDICINE by Dr Abhishek Jaiswal is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Based on a work at learnpsm@blogspot.com.
Permissions beyond the scope of this license may be available at jaiswal.fph@gmail.com.