Bagpipe Lung – a piper-MD’s perspective

Discussion

One of the first things that should be considered when evaluating medical literature is to identify what kind of article you are reading. This is an important step as it allows us to easily assess the strength of the evidence. In this instance, the article was in the form of a case report. These are often short and aim to present interesting cases with the hope of adding to the current knowledge on a topic. However, it must not be forgotten that more often than not these cases are unique or rare thus adding to the appeal of writing it up for publication.

There would be no point in publishing “me too” articles that do not add to our current knowledge. Therefore, when considering the article in question, we must bear in mind that this is likely to be an uncommon presentation of Hypersensitivity Pneumonitis.

Additionally, this type of publication provides us with a low level of evidence, that is, that the conclusions made do not have the strongest evidence to base it on. The diagram in Figure 1 outlines the hierarchy of evidence with the strongest being at the top, and weakest at the bottom.⁽¹⁰⁾ More specifically, articles that review all of the current data in a field and then come to conclusions based on this review, provide us with the strongest possible evidence (Systematic Reviews and Meta-Analyses), while opinions from a single person – even an expert in his or her given field – provide us with the weakest. Case reports can be useful in identifying previously unknown presentations of conditions, as described here, but there are far superior methods of gaining strong evidence.

Another thing to consider is the source of the evidence. By this I don’t mean whether it is online or in paper form, but in which journal the article is published. The more respected and cited (i.e., how often other authors use this journal as a reference) a journal is, the more likely that its contents are of a high standard.

When hearing about the latest medical breakthroughs in the media, often the evidence is published in the British Medical Journal, The Lancet or The New England Journal of Medicine. These are examples of some of the highest-rated journals . . .