Ask yourself what the population in the study was like and whether it was like your own. Has the test been compared to an appropriate gold standard?

You would be right to be sceptical of results from studies conducted in specialised environments. Our patients are unlike any others!

Click here to look at Table 2 on page 1233 of the PDF file of the paper, then decide whether these patients are like the patients seen in your ED

‘External validity’ is a term that simply means: ‘If this study was done on different patients, in different places, by different doctors, would you expect the same result?’