Lesley Wood research student, Matthias Egger head of department and professor of epidemiology and public health, Lise Lotte Gluud senior registrar, Kenneth F Schulz vice president of quantitative sciences and clinical professor, Peter Jüni head of division and reader in clinical epidemiology, Douglas G Altman director and professor of statistics in medicine et al
Wood L, Egger M, Gluud L L, Schulz K F, Jüni P, Altman D G et al.
Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study
BMJ 2008; 336 :601
doi:10.1136/bmj.39465.451748.AD