Table 2 Details about methodological quality of included studies

Was the assigned treatment adequately concealed prior to allocation?

2

1

2

2

A clearly stated aim

Were the outcomes of participants who withdrew described and included in the analysis?

0

2

1

1

Inclusion of consecutive patients

Were the outcome assessors blinded to treatment status?

2

0

0

0

Prospective data collection

Were the treatment and control group comparable at entry?

2

2

1

2

Endpoints appropriate to the aim of the study

Were the participants blind to assignment status after allocation?

0

0

1

2

Unbiased assessment of the study endpoint

Were the treatment providers blind to assignment status?

0

0

2

2

A follow-up period appropriate to the aims of the study

Were care programmes, other than the trial options, identical?

2

2

2

2

Less than 5 % loss to follow-up

Were the inclusion and exclusion criteria clearly defined?

2

2

0

0

Prospective calculation of the sample size

Were the interventions clearly defined?

2

2

2

2

Prospective calculation of the sample size

Were the outcome measures used clearly defined?

2

2

1

2

An adequate control group

Were diagnostic tests used in outcome assessment clinically useful?

2

2

2

1

Baseline equivalence of groups

Was the surveillance active, and of clinically appropriate duration?

2

2

2

2

Adequate statistical analyses