Chronic Cough in Patients With ILD Linked to Reduced Quality of Life

A new systematic review examines the impact of chronic cough in patients with idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases (ILD). The review, published in Respiratory Research, aims to inform future research, treatment, and care models for these patients.¹

The review, which included 61 studies, reveals that chronic cough is a common symptom in patients with ILD, particularly IPF. According to the study, chronic cough is reported in 50% to 90% of patients with IPF, significantly affecting their quality of life. "Cough tends to persist over time in ILD populations," the study notes, adding that cough often emerges as an early symptom of these diseases​.

Patients frequently cited cough as one of the most distressing symptoms they face, with up to one-third of patients with ILD ranking it as their worst symptom | Image Credit: © Tetiana - stock.adobe.com

Among the studies reviewed, researchers identified a wide range of methods used to measure cough severity and its impact on quality of life. The most frequently used tools to assess cough included the Cough Severity Visual Analogue Scale (VAS) and objective cough counts, while the St. George's Respiratory Questionnaire and Leicester Cough Questionnaire were the most common measures for assessing health-related quality of life (HRQOL).

"Quantitative studies in patients with IPF consistently demonstrated the detrimental effect of cough on HRQOL, while qualitative studies in this population highlighted the significant cough-related burden experienced by patients and their caregivers, including disruption of daily activities, sleep deprivation, fatigue, incontinence, social embarrassment, and psychological distress," the authors added. This association was particularly evident in IPF, although similar trends were observed in other ILDs, such as connective tissue disease–associated ILD and sarcoidosis.

Patients frequently cited cough as one of the most distressing symptoms they face, with up to one-third of patients with ILD ranking it as their worst symptom.² They also described their cough as “incredibly bothersome,” often occurring during exertion but also causing sleep disruption and incontinence. Caregivers also reported feelings of distress and a sense of helplessness.

A lack of standardized tools to assess cough in patients with ILD was also evident during the review. The variability in measurement approaches makes it challenging to compare findings across studies and fully understand the true burden of cough. "Development of a standardized and disease-specific cough assessment tool, alongside validation of existing tools in these populations, could facilitate more consistent and reliable between-study comparisons," the authors noted, adding, "Our synthesis highlights the need for standardized assessment tools, along with dedicated studies, particularly in non-IPF ILDs and on the economic burden of cough."¹

Although the review did not specifically explore the economic impact of chronic cough, one study included in the synthesis found an association between severe cough and loss of workplace productivity.³ "Specifically, the study showed that the odds of productivity loss (N = 148) increased by 3% for every 1 mm increase in cough severity VAS," the authors added.¹

Despite the burden chronic cough puts on patients, the review found limited treatment options explicitly targeting cough in patients with ILD. The review highlights that chronic cough in these patients is often multifactorial, involving mechanical distortion, heightened cough reflex sensitivity, and increased mucus production. Additionally, comorbid conditions such as gastroesophageal reflux disease and asthma further exacerbate the problem.^4,5 Current therapeutic options primarily focus on managing the underlying disease, and few studies have explored interventions specifically targeting cough.

The correlation between cough severity and poor quality of life, combined with the lack of targeted treatments and management for cough in these patients, “remains a significant unmet clinical and patient need,” the authors wrote, adding, "We hope by highlighting the impact and breadth and magnitude of the burden of cough in patients with IPF and ILD, we can encourage further research," and “ultimately help pave the way for the development of effective treatment and support strategies for cough in IPF/ILD.”¹

References

1. Green R, Baldwin M, Pooley N, et al. The burden of cough in idiopathic pulmonary fibrosis and other interstitial lung diseases: a systematic evidence synthesis. Respir Res. 2024;25(1):325. doi:10.1186/s12931-024-02897-w
2. Lan NSH, Moore I, Lake F. Understanding cough in interstitial lung disease: a cross-sectional study on the adequacy of treatment. Intern Med J. 2021;51(6):923-929. doi:10.1111/imj.14837
3. Algamdi M, Sadatsafavi M, Fisher JH, et al. Costs of workplace productivity loss in patients with fibrotic interstitial lung disease. Chest. 2019;156(5):887-895. doi:10.1016/j.chest.2019.04.016
4. Mann J, Goh NSL, Holland AE, Khor YH. Cough in idiopathic pulmonary fibrosis. Front Rehabil Sci. 2021;2:751798. doi:10.3389/fresc.2021.751798
5. Wakwaya Y, Ramdurai D, Swigris JJ. Managing cough in idiopathic pulmonary fibrosis. Chest. 2021;160(5):1774-1782. doi:10.1016/j.chest.2021.05.071