You are having lunch in the hospital cafeteria when one of your colleagues raises the issue of the safety of β-adrenergic agonists in the treatment of asthma. Your colleague feels uncertain about how to respond to patients asking him about media reports of an increased risk of death associated with these medications. Another colleague mentions a key article on this topic that generated much of the publicity, but she cannot recall the details. You all agree that this is an issue that arises frequently enough in your practices that you should become familiar with the evidence contained in the article that your patients have heard about. You volunteer to search the literature for the key article and report back to your colleagues in the next few days.
The next day you do a MEDLINE search using the following terms: asthma (MH) (MH stands for MeSH heading,