How best to assess cough as an outcome measure

Abstract

As part of their work in updating the CHEST Organization's 2006 cough guidelines, the CHEST Expert Cough Panel has spoken about the importance of routinely measuring cough outcomes with valid and reliable tools in clinical research studies1 and in the clinic.2 Based on a systematic review of literature that focused on intervention fidelity to cough guidelines,3 the panel came to understand that authors infrequently did what they said they did or did not document what they said they did. With respect to using standardized or validated tools to accurately measure patient‐reported outcomes, less than half of the published studies in this systematic review used a previously validated or standardized severity scale, and when such a tool was used, only 35% specified, but with variable clarity, what degree of change constituted acceptable improvement.3 Because all of the studies analysed in the systematic review involved series of patients seen in clinics, the panel strongly believed that the assessment of cough severity, at the very least, should be and could be assessed each and every time patients were seen in clinic, even if they were not participating in a formal research study.3 Moreover, because of the potential of recall bias,4 the panel recommended the use of tools that prospectively have patients assess where their cough severity is at the time of the visit rather than have them try to remember and estimate if their cough is better than it was on the last visit.