Table 2 Quality assessment for non-randomized trials

A clearly stated aim

Inclusion of consecutive patients

Prospective data collection

Endpoints appropriate to the aim of the study

Unbiased assessment of the study endpoint

A follow-up period appropriate to the aims of study

Less than 5% loss to follow-up

Prospective calculation of the sample size

An adequate control group

Contemporary groups

Baseline equivalence of groups

Adequate statistical analyses

Total score