"In smokers with a cough, does a chest x-ray or chest CT have a better positive or negative predictive value for lung cancer?"
Breaking a foreground question in the PICO format helps frame the question, and makes it easier to develop search terms to use in databases such as PubMed to find the best evidence.
If we use the foreground question from the example above, our PICO might look like this:
NOTE! Not all PICOs will have comparisons.
Resources at the top of the evidence pyramid:
See the sections below on point-of-care tools and article databases to find answers to foreground questions.