Methodological quality
18 Single A, et al., compilers. HTAi consumer and patient glossary: a beginner’s guide to words used in health technology assessment. Version 1. (Edmonton (AB)): Health Technology Assessment international (HTAi); 2009. 19Verhagen AP, de Vet HC, de Bie RA, Boers M, van den Brandt PA. The art of quality assessment of RCTs included in systematic reviews. J Clin Epidemiol. 2001;54(7):651–4. 20
Lundh A, Gotzsche PC. Recommendations by Cochrane Review Groups for assessment of the risk of bias in studies. BMC Med Res Methodol. 2008,8:22.
The extent to which the design, conduct and analysis of a study are likely to have prevented systematic error and to have produced results that are reliable and valid.
Note 1: Better quality studies are more likely to yield results that are less biased and closer to the true value for an outcome than poorer quality studies.