Kang et al conducted a 4-year retrospective cohort study to determine the longitudinal outcomes in patients with chronic cough. They also investigated the factors that predict cough persistence.

The study included adults who had recently visited a cough clinic from 2012 to 2013. The Hull Airway Reflux Questionnaire (HARQ) helped evaluate reflux cough symptoms. A follow-up survey done in 2016-2017 evaluated cough persistence. Overall, there were 418 participants, and 323 of these were a part of the follow-up study.

In comparison with patients with remitted cough, more patients with chronic persistent cough had family history of chronic cough as well as cold air-sensitive cough. While the total HARQ score was not different, two items scored higher in chronic persistent cough - cough with eating and cough with certain foods. 

Multivariate analyses revealed that a family history of chronic cough (adjusted odds ratio 4.27 [95% confidence interval 1.35-9.89]), cold air-sensitive cough (2.01 [1.09-3.73]), and cough with eating (1.22 [1.02-1.45]) had a relation with chronic persistent cough at 4 years.

To sum up... 

• Cough persisted in nearly 20% of the patients, 4 years after assessment and treatment.
• Family history, cold air-sensitivity, or reflux cough, appear to be linked with persistent cough. 

Source: Kang S-Y, Song W-J, Won H-K, et al.Cough persistence in adults with chronic cough: A 4-year retrospective cohort study. Allergol Int. 2020 Oct;69(4):588-593.