Table 1

 Methods assessment; validity criteria for which bias must be considered likely, and validity and data extraction criteria for which incomplete information hampered assessment

First authorValidity scoreBias considered likely for validity criteria concerning:Insufficient information for validity criteria concerning:Data extraction scoreInsufficient information for data extraction criteria concerning:
Number of satisfied validity criteria (maximum = 10)Population criteria 1–3Intervention criteria 4–7Follow up criteria 8–10Population criteria 1–3Intervention criteria 4–7Follow up criteria 8–10Number of satisfied data extraction criteria (maximum = 8)Population criterion 1Intervention criteria 2–5Follow up criteria 6–8
Paradise II, three way trial64, 78, 98
Paradise II, two way trial54, 6, 78, 98
Mawson I and II44, 6, 78, 95513, 5
McKee II44, 791, 35547, 8
Paradise I234, 6, 78, 91, 277
McKee I11, 24, 6, 78, 93567, 8