In 1968, Wilson and Jungner published 10 “principles” for evaluating screening programs, criteria widely used since then.
Summary of Wilson and Jungner Criteria
Principle | Further Explanation by Wilson and Jungner |
The condition sought should be an important health problem. | Does not depend on prevalence only; must consider from the point of view of the individual and community; conditions with serious consequences for either individuals or the community may both justify screening. |
There should be an accepted treatment for patients with recognized disease. | Perhaps most important criterion; unless there is an effective treatment, actual harm may be done; requires answering 2 questions: 1) Does treatment at the presymptomatic borderline stage of a disease affect its course and prognosis? 2) Does treatment of the developed clinical condition at an earlier stage than normal affect its course and prognosis? If the answer to question 1 is not clearly yes, then there is no case for screening. For question 2, effective treatment is usually “assumed.” |
Facilities for diagnosis and treatment should be available. | Must have facilities available for the diagnosis and treatment of people found positive by screening. |
There should be a recognizable latent or early symptomatic stage. | Must be a reasonable asymptomatic period in the natural history of the condition. |
There should be a suitable test or examination. | Test must be easy and quick, may be less sensitive and specific than a diagnostic test. In a screening test, one may accept a higher false-positive rate, but a high false-negative rate would not be acceptable. |
The test should be acceptable to the population. | Acceptability is related to the nature of the risk involved and the extent to which “the ground is prepared previously by health education.” |
The natural history of the condition, including development from latent to declared disease, should be adequately understood. | It is necessary to have conducted enough research to know 1) What changes should be regarded as pathologic and what should be considered physiologic variations? and 2) Are early pathologic changes progressive? |
There should be an agreed policy on whom to treat as patients. | It is necessary to know, Is there an effective treatment that can be shown either to halt or to reverse the early pathologic changes? We may not know the answer to this question because randomized controlled trials of screening or treatment have not been conducted. We must be careful to heed the Hippocratic principle of primum non nocere. There is a “borderline” problem whereby people are found by screening who are neither clearly normal nor abnormal. It is important to have a clear policy for either treatment or follow-up of these people. |
The cost of case finding (including diagnosis) should be economically balanced in relation to possible expenditure on medical care as a whole. | There are 2 general aims of screening: to improve health and to reduce costs. It is not certain that screening will reduce costs; there is a need for randomized controlled trials of screening to determine this, although these trials are difficult to conduct. |
Case finding should be a continuing process and not a “once and for all” project. | The benefit of “single-occasion” screening is limited. |
References:
- Harris R, Sawaya GF, Moyer VA, Calonge N. Reconsidering the criteria for evaluating proposed screening programs: reflections from 4 current and former members of the U.S. Preventive services task force. Epidemiol Rev. 2011;33:20-35. [Medline]
- Wilson JMG, Jungner G; Principles and Practice of Screening for Disease, World Health Organization, 1968
Created Mar 22, 2017.