1. Gluud LL. Bias in clinical intervention research. Am J Epidemiol. 2006;163(6):493–501.
2. Higgins JP, Altman DG, Gotzsche PC, Juni P, Moher D, Oxman AD, Savovic J, Schulz KF, Weeks L, Sterne JA. The Cochrane Collaboration's tool for assessing risk of bias in randomised trials. BMJ. 2011;343:d5928.
3. Higgins JPT, Green S. Cochrane handbook for systematic reviews of interventions version 5.1.0 [updated March 2011]: The Cochrane Collaboration; 2011. Available from
https://training.cochrane.org/handbook
. Accessed 2 Apr 2019.
4. Roberts C, Torgerson DJ. Understanding controlled trials - baseline imbalance in randomised controlled trials. Br Med J. 1999;319(7203):185.
5. Fu R, Vandermeer BW, Shamliyan TA, O'Neil ME, Yazdi F, Fox SH. AHRQ methods for effective health care: handling continuous outcomes in quantitative synthesis. Methods guide for effectiveness and comparative effectiveness reviews. Rockville: Agency for Healthcare Research and Quality (US); 2008.