Correction to guidance for assessing imprecision with continuous outcomes

Systematic review and guideline developers take note: the authors of the 2011 guidance on assessing imprecision within the GRADE framework have recently issued a correction related to the assessment of information size when evaluating a continuous outcome.

Whereas the article stated originally that a sample size of approximately 400 (200 per group) would be required to detect an effect size of 0.2 standard deviations assuming an alpha of 0.05 and a power of 0.8, the correct number is actually 800 (400 per group). 

The full corrigendum can be read here.