Objective cough frequency in Idiopathic Pulmonary Fibrosis

Nineteen IPF patients, mean age 70.8 years ± 8.6, five female (26.3%) were studied. Subjects performed full pulmonary function testing, 24 hour ambulatory cough recordings, completed a cough related quality of life questionnaire (Leicester Cough Questionnaire) and subjectively scored cough severity with a visual analogue scale. Ambulatory cough recordings were manually counted and reported as number of coughs per hour.The 24hr cough rates were high (median 9.4, range 1.5-39.4), with day time rates much higher than night time (median 14.6, range 1.9-56.6 compared to 1.9, range 0-19.2, p = 0.003). Strong correlations were found between objective cough frequency and both the VAS (day r = 0.80, p < 0.001, night r = 0.71, p = 0.001) and LCQ (r = -0.80, p < 0.001), but not with measures of pulmonary function. Cough rates in IPF were higher than healthy subjects (p < 0.001) and asthma patients (p < 0.001) but similar to patients with chronic cough (p = 0.33).This study confirms objectively that cough is a major, very distressing and disabling symptom in IPF patients. The strong correlations between objective cough counts and cough related quality of life measures suggest that in IPF patient's, perception of cough frequency is very accurate.Idiopathic Pulmonary Fibrosis (IPF) is a progressive fibrotic disease of unknown aetiology with an estimated incidence of 6-20 cases per 100,000 of the population. Clinical features include dry cough, breathlessness, restrictive spirometry, end-inspiratory crackles, reduced oxygenation and finger clubbing. High resolution computer tomography (HRCT) shows a distinctive pattern of sub pleural shadowing and later in the disease honeycomb fibrosis [1]. Cough in IPF, is both a presenting and a complicating clinical feature [2].Swigris et al conducted in-depth interviews with IPF patients to determine how the disease affects their lives [3]. They described cough as being dry, nonproductive and hacking with significant physical and social impac