Chronic diseases and health promotion

Part Three. What works: the evidence for action

Chapter Two. Review of effective interventions

Clinical prevention. Success factors

Clinical prevention is designed either to reduce the risk of disease onset or to reduce complications of disease in people living with disease. There are a number of highly effective clinical interventions that, when properly delivered, can reduce death and disease and improve the quality of life of people at risk of, or living with, chronic diseases. These include supporting behaviour change, the use of pharmacological agents and surgery. One example - combination drug therapy (aspirin, beta blocker, diuretic, statin) for people with an estimated overall risk of a cardiovascular event above 5% over the next 10 years - was shown to be very cost-effective in all regions by the WHO-CHOICE project.

Success factors

A combination of interventions is required to realize the full potential of risk reduction.

  • Treatment approaches based on overall risk, which take into account several risk factors at once, are more cost-effective than those based on arbitrary cut-off levels of individual risk factors.
  • For some diseases (such as cataract) single, highly cost-effective interventions are available.

Reducing the risks of disease onset

Clinical interventions are a key component of comprehensive programmes for reducing the likelihood of disease onset. Individuals are at highest risk when they have several risk factors or when they have established disease. To reduce the likelihood of disease onset among high-risk individuals, screening and treatment need to be based on an assessment of overall risk (as determined by multiple rather than single risk factors).