Introduction

Is this trial internally valid?

By this we mean, “how well was the trial conducted and do you trust the result?”

You need to decide this before you can consider applying the result elsewhere.

The JADAD score is a way of assessing the internal validity of a trial. The perfect double-blinded randomised controlled trial would score five.

On the next page you’re going to apply the JADAD score to the study we’ve been looking at.