Assessing publication bias in meta-analysis.

BACKGROUND

Although publication bias is a concern when using meta-analysis, techniques for assessing for its potential appear to be underused in nursing.

OBJECTIVES

To demonstrate several methods, both graphical and statistical, of assessing for publication bias.

METHODS

Four methods are described and demonstrated, ranging from the familiar fail-safe N to the trim-and-fill method, using the same contrived data set.

RESULTS

Methods vary in their conclusion about the presence of potential publication bias in the example presented. Some limitations of the methods are noted to assist meta-analysts in determining which to consider using.

CONCLUSION

Given that publication bias can affect the validity of meta-analytic studies, researchers are encouraged to use more than one method to assess for bias so that clinicians and decision-makers can have the best possible information available.