We need better research on which to base policy decisions

What should be done in Britain about existing and proposed programmes to screen preschool children for the related conditions of amblyopia, refractive error, and strabismus? Those who have visited this debate before may not be surprised that the recently published systematic review on preschool vision screening from the NHS Centre for Reviews and Dissemination identified serious deficiencies in the research evidence which informs current policy.1 However, the conclusions that “Providers currently offering screening programmes should consider discontinuing them” and, “From an ethical point of view, it is appropriate to continue to screen only in the context of a controlled trial of treatment” will undoubtedly prove more controversial.

The available research evidence has been interpreted differently in similar reviews from North America,2 3where it has been concluded that preschool vision screening should continue. Why have reviewers reached different conclusions from essentially the same data? By integrating existing information in an unbiased manner, systematic reviews should provide data for …