Their effectiveness cannot be judged by randomised controlled trials

Papers p 719

In preventive health services the old axiom that lack of evidence is not evidence of lack is important. No one should be surprised that the meta-analysis undertaken by Elkan et al (p 719), the systematic reviews by Stuck et al and van Haastregt et al, and the randomised controlled trials undertaken by these and other researchers produce apparently conflicting results.1-3 Most importantly, the lack of a clear justification for preventive home visits to older people, in terms of the outcomes of mortality, institutionalisation, and particular measures of function, should not be used as an excuse for discontinuing the service.

Some of the limitations of meta-analyses and systematic reviews were identified in the correspondence that followed the publication of van Haastregt's review.3 The reliance of these approaches on randomised controlled trials recognises that such trials are the most rigorous form of assessing the effectiveness of medical interventions but fails to recognise that they may not be adequate or appropriate …