Problems caused by heterogeneity in meta-analysis: a case study of acupuncture trials. 


Author: Prady SL, Burch J, Crouch S, Macpherson H.

Affiliation: Department of Health Sciences, The University of York, , York, UK. 
Conference/Journal: Acupunct Med.
Date published: 2013 Oct 18
Other:
  Special Notes:  doi: 10.1136/acupmed-2013-010364   ,  Word Count: 158  
    

OBJECTIVES:

To illustrate the pitfalls of using meta-analysis to combine estimates of effect in trials that are highly varied and have a high potential for bias.

METHODS:

We used a random-effects meta-analysis to pool the results of 51 sham-controlled acupuncture trials of chronic pain published in English before 2008 and explored the heterogeneity using meta-regression. We repeated the process on a subset of these trials that used a visually credible non-penetrating sham device as control (N = 12).

RESULTS:

In both analyses there were high levels of heterogeneity and many studies were at risk from potential bias. The heterogeneity was not explained by meta-regression.

CONCLUSIONS:

Trials of interventions that have high potential for bias, such as many in the acupuncture literature, do not meet the assumptions of the statistical procedure that underlie random-effects meta-analysis. Even in the absence of bias, heterogeneity in meta-analyses is not accounted for by the CIs around the pooled estimate.

KEYWORDS:

Acupuncture, Statistics & Research Methods, Systematic Reviews



PMID: 24140758