Introduction Cough is a major symptom of Idiopathic Pulmonary fibrosis (IPF), a progressive, fatal lung disease with median survival of 3 years. The first study to suggest cough as an independent predictor of disease progression, reported it in 84% of the population.¹ The only study to quantify cough in 19 IPF patients, reported strong correlation between objective cough counts and cough related quality of life² There is a lack of studies investigating the prevalence, pathogenesis or treatment of cough in IPF. We set up a study to evaluate the prevalence of cough in an incident IPF and Non specific Interstitial Pneumonia (NSIP) population.

Methods A prospective, multi-centre, observational, cohort study, PROFILE-Central England (September 2009 to June 2014) was set up. Patients had a diagnosis of definite or probable IPF or NSIP based on the ATS consensus. Leicester cough questionnaire (LCQ) was used to assess presence or absence of cough at baseline. Furthermore,the cohort was divided into 3 groups to assess severity of cough: Mild (17–20), Moderate (11–16.9) and Severe (<11).

Results 312 incident patients with IPF or NSIP were enrolled. 261/312(83.6%) patients had incident IPF whilst 51/312(16.4%) had NSIP. The mean age of the cohort was 73.5 years (35–90 years). 235/312(76%) were males with mean age 73.7 years (47–90 years); 74/312(24%) were females with mean age of 72.9 years (35.8–88.8 years).

261/312(83.6%) reported cough compared with 51/312(16.4%) who reported no cough. Of the patients who reported cough, 45/261(17.2%) had severe cough, 112/261(42.9%) had moderate cough and 104/261(39.8%) had mild cough. There was no effect of gender, however, older cohort reported more cough (age >55 years; p = 0.014). Smoking may be a confounder, however the number of current smokers in the cohort is too small (p = 0.05).

Interestingly both NSIP and IPF cohort reported cough; however, proportionally NSIP patients have less cough (14/51,27.4%) compared with IPF (37/261, 14%).

Conclusions Cough occurs in a huge majority of patients with both IPF and NSIP. Cough appears to be a greater problem in older patients.

References

1. Ryerson CJ et al. Cough predicts prognosis in idiopathic pulmonary fibrosis. Respirology. 2011 Aug;16(6):969–75

2. Key AL et al. Objective cough frequency in Idiopathic Pulmonary Fibrosis. Cough. 2010;6:4