Ask yourself if the study is externally valid or generalisible?

By this we mean, “would you expect the same result if this trial was carried out in another group of patients?”

After reading any trial, you should ask yourself “should I apply this to my own patients?”, otherwise there is no point in reading it! Try to decide whether the patients in the trial are similar to your own and whether you can do what they did.

Only bother doing this if you think that the trial is internally valid. There is no point trying to generalise a finding that is not internally valid.

Trials should always be assessed for external and internal validity