What Is Evidence Based Medicine?

When emPowereD discusses interventions like exercise or levodopa, we often use the phrases “evidence-based” or “the evidence shows”. But what does that actually mean?

Medicine and other evidence-based health care domains (e.g. Allied Health) are what's known to be evidence-based practices. That means decisions about tests, medications, and treatments aren't based on opinion or tradition, they're built on evidence gathered carefully over time, using the scientific method.

How is evidence established?

Medical evidence comes from the scientific method: a structured process of asking a specific question, testing it, and checking whether the results hold up. Research usually starts with a gap in knowledge or an unanswered clinical question. From there, scientists design a study to test whether there's a meaningful relationship between two things. 

For example: “If a patient has Parkinson's disease, and we treat them with oral levodopa, will their motor symptoms improve?”

A single study is never enough. For a result to count as evidence, it has to be objective and reproducible,  meaning other researchers, working with different patients in different settings, can repeat the same kind of study and reach the same conclusion. When a series of studies (usually requiring large numbers), each examining the same question in a different way, keep arriving at the same result, that's when something becomes an established medical fact.

What does this mean for me?

When a doctor or specialist makes an evidence-based recommendation, it's built on an enormous body of work.  This means research carried out by scientists and clinicians over many years, tested across thousands of patients, reviewed by independent experts, and refined through many separate studies.

Of course, every person is different, and some may respond better to certain treatments than others, and individual preference is incredibly important. But it's worthwhile knowing that the options available to you aren't guesswork, they've been tested, repeated, and shown to be effective.