APPENDIX 5

Screening Quality Ratings

Study (Year)Random AssignmentAllocation ConcealedGroups Similar at BaselineEligibility Criteria SpecifiedBlinding: Outcome Assessors or Data AnalystsIntention-to-Treat AnalysisReporting of Attrition, Contamination, etcDifferential Loss to Follow-up or Overall High Loss to Follow-upAppropriate Analysis Including Cluster CorrelationFunding SourceExternal ValidityQuality Rating
Williams et al20 (2002) and Williams et al21 (2003)NoYesYesYesCannot tellNoNoYesNot applicableMedical Research Council; R&D Directorate; National Health Service Executive South West; National Eye Research CentreHighFair