Evidence-based medicine, practice and policy

Evidence-based medicine, evidence-based practice and evidence-based policy are terms used to describe making decisions using scientific evidence instead of subjective opinion or other influences.

If a health service decided to start using a new drug because they had a good relationship with the company that made the drug, that decision would not be based on evidence. However, if they used systematic review of rigorous clinical trials to check that the drug was safe, effective, and affordable, then using the new drug would be an example of evidence-based medicine.

Evidence-based medicine and practice

Healthcare providers do not always make evidence-based decisions either. Sometimes health organisations provide forms of treatment that have not been proven to be effective in clinical trials. For example, a doctor could prescribing antibiotics due to pressure from patients, even thought they might not be clinically necessary. Using evidence is generally the best way to make decisions about healthcare and health policy, but there are limitations. For example, some forms of treatment that could be very helpful may be impossible to test using clinical trials. In addition, conducting, publishing, collecting and reviewing clinical trials can take a long time, which means that useful treatments can be delayed. Despite these limitations, evidence-based medicine is generally considered to be the most robust way to make medical decisions.

For more information on evidence-based medicine, see the Centre for Evidence-Based Medicine^{[external link]}.

Governments and evidence-based policy

Governments do not always base decisions on evidence, because politicians take other factors into account, such as their political ideology or how they think voters would react to the policy. In addition, politicians are often lobbied by powerful groups representing corporate interests.

Evidence-based policy often sounds straightforward, but becomes complicated when we try to apply it in the real world. For example, in UK debates about regulation of e-cigarettes, individual health researchers have argued for very different approaches. In this example, health researchers who all share the same goals of improving health and have access to the same evidence have reached different conclusions. It could be argued that policy can never be completely based on evidence, because, no matter how objective we try to be, our individual and cultural values influence how we interperet the available evidence.