News – Apr 18, 2018

Real World Evidence – an introduction

Everybody is talking about real world evidence (RWE) these days, but what is it exactly?

There is an abundance of articles on this topic that have, no doubt, been read by many people. This article aims to explain it in terms our Grandmothers could understand and is the first in a series of articles on RWE.


Where do we come from?

Traditional highly-controlled clinical trials play a critical role in documenting the safety and efficacy of drugs. They are designed to meet regulatory standards to obtain government approval to ultimately make drugs available to patients. Why is it essential to take this step beyond information from these trials? If a patient getting a drug is elderly or suffering from more than one chronic condition, it’s very possible that a patient such as this was not represented in the clinical trial. Also, use of treatments in routine clinical practice may differ substantially from the use in these highly controlled trials, for example with respect to adherence to the medication regime.

What is RWE? The actual definition is still evolving, but basically, real world evidence is evidence derived from the analysis and/or synthesis of data gathered in a real world setting. These data differ from a traditional clinical trial – the data is gathered either from an observational study or from a pragmatic trial. Okay, now you are asking “so what are these?”

An observational study is what the name says – the researchers observe subjects, or data provided them, that are a good sample of the target population and draw conclusions from those observations that could be valid for the entire target population. Sometimes the researchers also do additional tests as well. The biggest difference is that the subjects are not randomized to a specific treatment or intervention. When subjects are randomized, a study is called a clinical trial. The advantage of observational studies is that subjects are far less selected and tend to better represent the type of patients the drugs are ultimately prescribed for. Moreover, in observational studies, patients can typically be followed for much longer periods of time than in traditional clinical trials which permits the observation of longer term benefits and risks. However, sometimes the absence of randomization makes it impossible to draw really valid conclusions on drug effects.

A pragmatic trial, sometimes called a pragmatic clinical trial (PCT), is a randomized study that focuses on the relation between treatments and outcomes in routine clinical practice, rather than on proving causative relations between a single drug/intervention for outcomes under ideal circumstances, as is done in a more traditional randomized clinical trial. In contrast to “pragmatic”, these latter trials are called “explanatory”. Pragmatic trials thus also employ randomization but have a more open study populations and usually measure outcomes more relevant from a patient perspective. They combine elements from both observational studies and traditional clinical trials.

In part 2 of this series, we will talk about why RWE trials have become so popular.