WHO focuses on evidence-based screening programmes

WHO focuses on evidence-based screening programmes

Agency News

Copenhagen, Feb 12 : Emphasising the importance of evidence-based screening programmes, WHO/Europe has talked about the lack of information and understanding about the potential harm and the costs of implementing effective screening programmes in its new guide.

The WHO publication titled 'Screening programmes: a short guide to increase effectiveness, maximize benefits and minimize harm' points out that screening programmes have been a part of our public health tradition. It is greatly valued by the people as an essential part of health care. But as screening programmes proliferate, the public, health professionals and policymakers are asking whether “doing more” actually means “doing better”. “Evidence-based screening programmes have great potential to improve public health outcomes and advance universal health coverage. When organised effectively, they can prevent disease, reduce disability and cut mortality,” says Dr Hans Kluge, WHO Regional Director for Europe.

“But questions such as: How strong is the evidence base? What is the equation between benefit and harm? Are there potential ethical dilemmas? Are commercial interests involved? Will this exacerbate inequities? Those questions often remain unanswered.” Where there is good evidence that detecting a condition early will, overall, benefit those who are screened, and where good follow-up treatment is available, it may be appropriate to design and implement a formal screening programme, according to the report. But if screening interventions are not effective or even harmful, those same resources could be better used in other ways to improve the health of the population.

The decision about whether to implement a screening programme should be based on updated evidence, including an economic analysis to consider cost–effectiveness and implications for human, financial and other resources. This is particularly important given the emergence of new technologies, such as biomarkers, new imagery techniques or smart technologies, as these may lack a strong evidence base. Where possible, decisions on screening should be supported by modelling to estimate costs and benefits in different populations.

Once the decision to implement a screening programme has been made, the process should involve creating a series of sequential steps on a pathway, from identifying the population eligible for screening to ensuring that all those who require treatment receive it in the most effective way. While these steps may seem simple, creating a comprehensive, organised, high quality screening programme catering to a large population is a very complex task, requiring large number of resources and the development of capacity both inside and beyond the health system. A 1968 WHO report by Wilson and Jungner remains the benchmark for determining whether a screening programme is appropriate or not.

In short, the condition should be important and there should be an effective means to treat it to prevent progression, mitigate its effects or, ideally, cure it. Critically, there should also be a screening process that is effective, acceptable and affordable. Yet these principles are not always followed – programmes that are ineffective or even harmful exist or are being implemented. This may be due to various pressures related to both the demand and supply sides of screening, including commercial interests from the health-care industry.

For example, manufacturers of equipment used in screening employs marketing strategies to drive demand from the general public, policy-makers and health professionals. Any strategy for a new screening programme should consider the role played by the different actors driving demand and supply, including patients and the public, political decision-makers, health professionals and the health-care industry. (UNI)