The effectiveness and efficiency of screening in medical care

While smallpox, rabies, and cholera are particularly interesting because they demonstrate that only partial understanding of factors influencing disease may lead to highly effective preventive measures, this may not always be the case. Modern day epidemics of chronic noncommunicable diseases so far appear to be much more refractory and decisions to organise screening programmes have usually been taken on the basis of inadequate information. This approach runs the very real danger of providing health services which, however well organised they may become, could eventually be shown to be basically ineffective. Screening procedures of proven effectiveness are few in number.