Tool Campochiaro C. et al Guaraldi G. et al Colaneri M. et al Kewan T. et al Somers EC. et al Ip A. et al
Bias due to confounding 1 3 ? ? 2 3
Bias in selection of participants into the study 1 1 1 1 1 1
Bias in classification of interventions 1 1 1 1 1 1
Bias due to deviations from intended interventions 1 2 1 2 1 2
Bias due to missing data 1 1 1 1 1 1
Bias in measurement of outcomes 2 2 2 2 2 2
Bias in selection of the reported result 1 1 ? ? 2 2