Table 2.

Critical appraisal

Reporting	Did the study address a clearly defined issue?
	Did the authors use an appropriate method to answer the review question?
	Are the main outcomes, patient population and interventions tested clearly described?
	Are losses to follow-up reported and clearly described?
Bias and confounding effects	Were the patients recruited in an acceptable way?
	Was any attempt to randomise or blind patents or investigators reported?
	Have the authors identified all/any of the confounding factors?
	Was the follow-up of patients complete and long enough?
Usefulness of the study	Are the results useful to answer the review question?
	Do the results fit with the evidence from other studies?