Because cough is the single most common complaint for which patients seek medical care in the ambulatory setting, it is important for clinicians to have a management plan on how to approach the problem, says Richard S. Irwin, MD, Master FCCP. “The 2006 CHEST guidelines on the diagnosis and management of cough suggested that approaching cough based upon its duration was likely to be useful,” he adds. “Classifying cough as acute, subacute, and chronic allows for a standardized assessment by any provider, physician, or affiliate practitioner, so life-threatening conditions such as pneumonia or lung cancer are considered and ruled out first.  The provider has a systematic method for identifying the more common causes of cough based upon duration.”

 

Validating the Concept

In attempt to validate this concept and determine the usefulness of this approach, Dr. Irwin and colleagues completed a high-quality systematic review and published their results in CHEST. “The ultimate goal was to develop and publish a clinical practice guideline on how to manage cough,” Dr. Irwin says. “Because a trustworthy guideline is based upon a high-quality systematic review, that’s where we started. The methods that we used were those recommended and published by the National Academy of Medicine.

For the review, the topic writing committee of the CHEST Expert Cough Panel extracted data from an initial screening of nearly 300 studies, including participants from North America, South America, Europe, and Asia. “Because the investigators of these articles followed the 2006 CHEST guidelines with respect to the durations of cough, we feel confident that the results of our 2018 article reflect the global experience in evaluating cough,” adds Dr. Irwin.

Overall, the systematic review confirmed what was suspected in 2006, according to Dr. Irwin: that there is a set of differential diagnostic possibilities to consider that tend to be specific to acute, subacute, and chronic cough. Five key suggestions resulted from the review (Table), firstly that estimating the duration of cough be the first step in narrowing the list of potential diagnoses causing the cough in adults seeking medical care. “Secondly, because we now have more solid evidence that the CHEST cough guidelines for managing acute, subacute, and chronic cough work, we suggest that clinicians follow the management algorithms published in the January 2018 issue of CHEST.

 

Knowledge Gaps Remain

Dr. Irwin explains that while much has been learned since the publication of the 2006 CHEST cough guidelines, gaps in knowledge—that he hopes will be filled in the near future—remain, including:

  • A paucity of studies describing the spectrum and frequency of causes of acute and subacute cough. Prospective before-and-after-intervention studies performed using validated outcome tools to document improvement are needed.
  • A lack of confirmation of the reliability, validity, and efficacy of the 2018 CHEST cough management algorithms for acute, subacute, and chronic cough. Prospective randomized clinical trials, with usual care control groups, will need to be undertaken with validated cough outcome tools.
  • A need for an electronic version of the 2018 CHEST cough guidelines to help allow for ease of use and better adherence. “With the widespread use of electronic medical records, an electronic guideline should be widely disseminated, with validated outcomes measures that allow for cost-effective, pragmatic trials to be conducted in large populations,” says Dr. Irwin.

References

Irwin R, French C, Change A, et al. Classification of Cough as a Symptom in Adults and Management Algorithms. CHEST. 2018;153(1)196-209. Available at http://journal.chestnet.org/article/S0012-3692(17)32918-5/fulltext.