Measurement of cough

doi:10.1016/j.resp.2006.02.001

Respiratory Physiology & Neurobiology

Volume 152, Issue 3, 28 July 2006, Pages 329-339

https://doi.org/10.1016/j.resp.2006.02.001 Get rights and content

Abstract

Cough is one of the most common symptoms encountered by clinicians particularly when it is persistent. Assessment of cough is essential for determining treatment outcomes, testing new therapies and for study of pathophysiology and mechanisms. There are new tools for measuring different aspects of cough. Apart from the patient's subjective assessment of cough severity using clinical scores, the impact of cough on quality of life can be measured. Direct measurement of cough counts is now possible by using portable devices, but how the counts relate to severity is unclear. A measure of cough intensity is required. Cough reflex measured by response to inhaling citric acid or capsaicin provides a measure of cough sensitivity that may be related to cough severity. In many intervention studies of cough, the response has usually been measured in terms of physician assessment of cough and its changes in cough reflex. How the information obtained between these different measurements interrelate needs to be determined.

Introduction

Although cough has been a symptom that clinicians have had to deal with for a long time, only recently has serious thoughts been given to its measurement. The measurement of cough both from the clinical point of view and from the research angle has only been seriously undertaken over the last 20 years. Any advances in understanding of cough or in new antitussives can only derive from tools established for measuring cough. Cough can be measured both in subjective or objective ways, the latter by quantifying the events that we all can identify as a ‘cough’. The measurement of cough should include tools that measure both the amount and severity of cough. In addition, other measurements pertaining to cough include the assessment of the cough reflex, which may be an indication of the cough sensitivity, the degree of which may relate to the severity of cough. Cough is a problem that needs to be measured not only in patients in whom cough is the major symptom, but also in patients with chronic respiratory illness where cough may be a predominant symptom. There is a clear need for having both objective and subjective measures of cough for use in clinical practice, clinical research, and in the assessment of new therapies (Chung, 2004). However, more development and validation of these techniques is needed before we can have standardised measures that could be used by every clinician or researcher.

This review will examine three major areas of cough assessment: (i) measurement of cough by impact on health and quality of life; (ii) cough counts and severity; (iii) cough sensitivity. Each of these assessments provide a different aspect of cough but theoretically, there is little reason to doubt that these measurements should not correlate with each other.

Section snippets

Clinical subjective cough measures

Cough has been measured simply by asking the patient to provide his/her own appreciation of the frequency and severity of the cough; usually how the cough is affecting his/her daily living and activities, is obtained. Cough scores, cough diaries, cough symptom questionnaires and use of a visual analogue scale have all been developed although thorough validation of these measures have not been carried out. The notation of the patient, scaling of cough intensity and frequency and patients’

Cough-specific health-related quality of life questionnaires

The fact that chronic cough can have an impact on health status forms the basis of these questionnaires. Patients with chronic cough may seek medical advice for various reasons including worry about the cause of the cough, the presence of serious illness, anxiety, social embarrassment, and associated symptoms such as syncope or urinary incontinence. The more general respiratory questionnaires such as the St. Georges Respiratory questionnaire (SGRQ) contains only two items specific to cough

Definition of cough: what is a cough?

The definition of a cough may not sound too philosophical a question to tackle when it comes to monitoring of cough. Cough is primarily a characteristic sound that can be distinguished by the human ear to be quite unique from other sounds. However, because most cough monitors uses a microphone to record the cough sound, and most software programs are unable to distinguish cough from other closely related sounds, it is necessary to obtain other properties of the cough which could be used to

Early methods

The need for monitoring cough events is recognised by most researchers for a long time. Early methods recorded cough in non-ambulatory patients, usually limited to short periods of time (Barach et al., 1955, Chernish et al., 1963). Pneumographic recording of thoracic pressure change during cough and measurement of airflow have been used to count cough numbers and the use of the cassette recorder using a free-air microphone was described in the 1960s (Loudon and Brown, 1967, Reece et al., 1996).

Can quantitative analysis of the cough sound help in the diagnosis?

An interest in quantitative analysis of the cough sound has been generated with the hope that such analysis may be used for diagnostic purposes, as well as for assessing the severity of the disease process (Korpas et al., 1996). Analysis of the cough sound (the tussiphonogram) can often discern two components, with the first sound originating at the level of the tracheal bifurcation or below, while the second sound probably from the vocal cords. The second cough sound is often absent in

The cough reflex

The cough reflex has been studied using challenges such as low chloride content solutions and using single breath challenges with citric acid or capsaicin (Morice et al., 2001, Fuller, 2003). Capsaicin challenge is currently the challenge of choice used by most investigators, being tolerable and acceptable test, with the possibility of performing reproducible dose–responses (Dicpinigaitis, 2003, Dicpinigaitis and Alva, 2005). Usually the response is measured as the concentration of capsaicin

References (74)

B. Bergman et al.
The EORTC QLQ–LC13: a modular supplement to the EORTC core quality of life questionnaire (QLQ-C30) for use in lung cancer clinical trials. EORTC Study Group on Quality of Life
Eur. J. Cancer
(1994)
C.E. Brightling et al.
Induced sputum and other outcome measures in chronic obstructive pulmonary disease: safety and repeatability
Respir. Med.
(2001)
P.V. Dicpinigaitis
Short- and long-term reproducibility of capsaicin cough challenge testing
Pulm. Pharmacol. Ther.
(2003)
P.V. Dicpinigaitis et al.
Safety of capsaicin cough challenge testing
Chest
(2005)
C.T. French et al.
A comparison of gender differences in health-related quality of life in acute and chronic coughers
Chest
(2005)
C.T. French et al.
Evaluation of a cough-specific quality-of-life questionnaire
Chest
(2002)
E.F. Juniper et al.
Validation of a standardized version of the asthma quality of life questionnaire
Chest
(1999)
A.F. Kalpaklioglu et al.
Evaluation and impact of chronic cough: comparison of specific vs generic quality-of-life questionnaires
Ann. Allergy Asthma Immunol.
(2005)
J.A. Karlsson et al.
Pharmacological regulation of the cough reflex—from experimental models to antitussive effects in man
Pulm. Pharmacol. Ther.
(1999)
J. Korpas et al.
Analysis of the cough sound: an overview
Pulm. Pharmacol.
(1996)

A. Niimi et al.

Nature of airway inflammation and remodeling in chronic cough

J. Allergy Clin. Immunol.

(2005)

L. Pavesi et al.

Application and validation of a computerized cough acquisition system for objective monitoring of acute cough: a meta-analysis

Chest

(2001)

P. Piirila et al.

Differences in acoustic and dynamic characteristics of spontaneous cough in pulmonary diseases

Chest

(1989)

T. Salmi et al.

Long-term recording and automatic analysis of cough using filtered acoustic sign movements on static charge sensitive bed

Chest

(1988)

S. Subburaj et al.

Methods of recording and analysing cough sounds

Pulm. Pharmacol.

(1996)

B.J. Undem et al.

Physiology and plasticity of putative cough fibres in the Guinea pig

Pulm. Pharmacol. Ther.

(2002)

B. Avidan et al.

Temporal associations between coughing or wheezing and acid reflux in asthmatics

Gut

(2001)

M. Aylward et al.

Dextromethorphan and codeine: comparison of plasma kinetics and antitussive effects

Eur. J. Respir. Dis.

(1984)

I. Baiardini et al.

A new tool to assess and monitor the burden of chronic cough on quality of life: chronic cough impact questionnaire

Allergy

(2005)

A.L. Barach et al.

Clinical and physiological studies on the use of metacortandracin in repsiratory disease. 1. Bronchial asthma

Dis. Chest

(1955)

S.S. Birring et al.

Chronic tonsillar enlargement and cough: preliminary evidence of a novel and treatable cause of chronic cough

Eur. Respir. J.

(2004)

S.S. Birring et al.

Development of a symptom specific health status measure for patients with chronic cough: Leicester cough questionnaire (LCQ)

Thorax

(2003)

C.E. Brightling et al.

Airway inflammation, airway responsiveness and cough before and after inhaled budesonide in patients with eosinophilic bronchitis

Eur. Respir. J.

(2000)

A.B. Chang et al.

Subjective scoring of cough in children: parent-completed vs child-completed diary cards vs an objective method

Eur. Respir. J.

(1998)

A.B. Chang et al.

Subjective scoring of cough in children: parent-completed vs child-completed diary cards vs an objective method

Eur. Respir. J.

(1998)

A.B. Chang et al.

A randomised, placebo controlled trial of inhaled salbutamol and beclomethasone for recurrent cough

Arch. Dis. Child

(1998)

A.B. Chang et al.

Frequency and perception of cough severity

J. Paediatric Child Health

(2001)

S.M. Chernish et al.

Clinical evaluation of a new antitussive preparation

Ann. Allergy

(1963)

N.B. Choudry et al.

Sensitivity of the cough reflex in patients with chronic cough

Eur. Respir. J.

(1992)

N.B. Choudry et al.

Sensitivity of the human cough reflex: effect of inflammatory mediators prostaglandin E2, bradykinin, and histamine

Am. Rev. Respir. Dis.

(1989)

K.F. Chung

The clinical and pathophysiological challenege of cough

C.E. Cox et al.

The Sarcoidosis Health Questionnaire: a new measure of health-related quality of life

Am. J. Respir. Crit. Care Med.

(2003)

I.D. Cox et al.

An electromyographic method of objectively assessing cough intensity and use of the method to assess effects of codeine on the dose–response curve to citric acid

Br. J. Clin. Pharm.

(1984)

M.A. Coyle et al.

Evaluation of an ambulatory system for the quantification of cough frequency in patients with chronic obstructive pulmonary disease

Cough

(2005)

F. Dalmasso et al.

Bioacoustics of cough during bronchial inhlation challenge (BIC) with methacholine

Eur. Resp. J.

(2001)

P.W. Davenport et al.

Psychophysical assessment of the urge-to-cough

Eur. Respir. Rev.

(2002)

L.A. Debreczeni et al.

Spectral analysis of cough sounds recorded with and without a nose clip

Bull. Eur. Physiopathol. Respir.

(1987)

Cited by (36)

Clinical efficacy of combination therapy of FuXi-Tiandi-Wuxing Decoction and anti-viral drugs in the treatment of novel coronavirus pneumonia: A prospective interventional study
2023, Journal of Herbal Medicine
The National Administration of Traditional Chinese Medicine of the People’s Republic of China (NATCM) and the State Administration of Traditional Chinese medicine (TCM) advocated a combination therapy of TCM and anti-viral drugs for novel coronavirus pneumonia (NCP) to improve the efficacy of clinical treatment.
Forty-six patients diagnosed with NCP were sequentially divided into intent-to-treat population: the experimental group (combination of FuXi-Tiandi-Wuxing Decoction and anti-viral drugs; n = 23) and the control group (anti-viral drugs only) (n = 23). The two groups were compared in terms of duration of fever, cough symptom score, fatigue, appetite, dyspnea, out-of-bed activities, chest computer tomography (CT) recovery, virological clearance, average length of hospital stay, and clinical effective rate of drug. After 6 days of observation, patients from the control group were divided into as-treated population: experimental subgroup (n = 14) to obtain clinical benefit and control subgroup (n = 9).
There was a significant improvement in the duration of fever (1.087 ± 0.288 vs 4.304 ± 2.490), cough (0.437 ± 0.589 vs 2.435 ± 0.662; P < 0.05), chest CT evaluation (82.6% vs 43.4%; P < 0.05), and virological clearance (60.8% vs 8.7%; P < 0.05) in patients of the experimental group compared with patients in the control group. Further observation in as-treated population reported that cough (0.742 ± 0.463 vs 1.862 ± 0.347; P < 0.05) and fatigue (78.5% vs 33.3%; P < 0.05) were significantly relieved after adding FuXi-Tiandi-Wuxing Decoction to the existing treatment.
An early treatment with combination therapy of FuXi-Tiandi-Wuxing Decoction and anti-viral drugs significantly relieves the clinical symptoms of NCP, shows improvement in chest CT scan, improves virological clearance, shortens average length of hospital stay, and reduces the risk of severe illness. The effect of FuXi-Tiandi-Wuxing Decoction in NCP may be clinically important and require further consideration.
Advances in mechanisms and management of chronic cough: The Ninth London International Cough Symposium 2016
2017, Pulmonary Pharmacology and Therapeutics
Citation Excerpt :
In addition, in conditions where chronic cough could be a predominant symptom such as asthma, COPD and pulmonary fibrosis, there is a characteristic inflammatory changes for that disease that could interact with cough sensory nerves. Measurement of cough hypersensitivity with citric acid or capsaicin indicate that these patients with chronic cough are usually accompanied by an excessive cough response to these inhaled tussigens, with sometimes correlation obtained between the level of the neuroinflammatory mediators and the degree of this cough tussive response, supporting the value of cough provocation tests in the diagnosis of CHS [16,17]. However, the value of these measurements must be tempered by the observations that successful pharmacological treatment of chronic cough with agents such as slow-release morphine and gabapentin have not always been accompanied by reduction in cough hypersensitivity measured by inhaled capsaicin or citric acid [18,19].
At the Ninth London International Cough Symposium held in June 2016, advances in chronic cough were presented. Chronic cough has been labelled as a cough hypersensitivity syndrome (CHS) with neuroinflammatory mechanisms likely to be the underlying mechanisms. The concept is that there is a stage of peripheral sensitisation induced by inflammatory factors setting up the scene for a central component that can be visualised by functional magnetic resonance imaging. There has also been progress in assessing CHS patients in the clinic in terms of measuring cough, with an increasing interest in assessing different types of cough associated with respiratory diseases such as asthma, COPD, bronchiectasis and pulmonary fibrosis. There is an emerging area of new antitussives in the form of neuromodulators. These advances have been paralleled by improvements in the management of patients with chronic cough. However, more work is needed but the future looks promising.
Automatic cough segmentation from non-contact sound recordings in pediatric wards
2015, Biomedical Signal Processing and Control
Citation Excerpt :
During consultation sessions physicians may also seek quantitative information on coughs, such as the frequency of occurrence of cough events over a given time interval. This information can be used to determine the nature (e.g., acute, chronic) and the severity of coughs as well as to monitor the efficacy of a treatment [5]. However, to obtain this information, physicians heavily rely on subjective reports of patients or their carers.
Cough is a common symptom of almost all childhood respiratory diseases. In a typical consultation session, physicians may seek for qualitative information (e.g., wetness) and quantitative information (e.g., cough frequency) either by listening to voluntary coughs or by interviewing the patients/carers. This information is useful in the differential diagnosis and in assessing the treatment outcome of the disease. The manual cough assessment is tedious, subjective, and not suitable for long-term recording. Researchers have attempted to develop automated systems for cough assessment but none of the existing systems have specifically targeted the pediatric population. In this paper we address these issues and develop a method to automatically identify cough segments from the pediatric sound recordings. Our method is based on extracting mathematical features such as non-Gaussianity, Shannon entropy, and cepstral coefficients to describe cough characteristics. These features were then used to train an artificial neural network to detect coughs segment in the sound recordings. Working on a prospective data set of 14 subjects (sound recording length 840 min), proposed method achieved sensitivity, specificity, and Cohen's Kappa of 93%, 98%, and 0.65, respectively. These results indicate that the proposed method has the potential to be developed as an automated pediatric cough counting device as well as the front-end of a cough analysis system.
Cough
2015, Murray and Nadel's Textbook of Respiratory Medicine: Volume 1,2, Sixth Edition
Concordance and discriminatory power of cough measurement devices for individuals with parkinson disease
2014, Chest
Dysphagia and aspiration pneumonia are two causes of morbidity in Parkinson disease (PD). In PD, impaired airway clearance can lead to penetration of foreign material, resulting in a high prevalence of aspiration pneumonia and death. This study examines three different devices for measurement of peak airflow during voluntary cough in healthy control subjects and those with PD. Two simple and low-cost devices for measuring peak cough airflow were compared with the “gold standard” pneumotachograph.
Thirty-five healthy control subjects and 35 individuals with PD produced voluntary cough at three perceived strengths (weak, moderate, and strong cough) for each of the three devices.
A significant difference in mean peak cough airflow was demonstrated for disease (F[1,56] = 4.0, P < .05) and sex (F[1,56] = 9.59, P < .003) across devices. The digital and analog meters were comparable to the gold standard demonstrating no significant difference (statistical) by device (digital vs analog) in receiver operating characteristic curve analysis. Both devices were discriminative of the presence of PD.
The analog and digital peak airflow meters are suitable alternatives to the gold standard pneumotachograph due to their low cost, portability, ease of use, and high sensitivity relative to normative peak cough airflows. Voluntary cough airflow measures may serve as a noninvasive means of screening for aspiration risk in target populations. Additionally, quantification of cough strength through use of predetermined limens for weak, moderate, and strong cough may assist clinicians in better describing and tracking cough strength as a contributing factor to aspiration risk.
Chinese national guideline on diagnosis and management of cough(2021)
2022, Zhonghua Jiehe he Huxi Zazhi / Chinese Journal of Tuberculosis and Respiratory Diseases

View all citing articles on Scopus

^☆: This paper is part of the Special Issue entitled “Cough and its Regulation”, guest-edited by John G. Widdicombe and Bradley J. Undem.

View full text

Measurement of cough☆

Abstract

Introduction

Section snippets

Clinical subjective cough measures

Cough-specific health-related quality of life questionnaires

Definition of cough: what is a cough?

Early methods

Can quantitative analysis of the cough sound help in the diagnosis?

The cough reflex

Eur. J. Cancer

Respir. Med.

Pulm. Pharmacol. Ther.

Chest

Chest

Chest

Chest

Ann. Allergy Asthma Immunol.

Pulm. Pharmacol. Ther.

Pulm. Pharmacol.

J. Allergy Clin. Immunol.

Chest

Chest

Chest

Pulm. Pharmacol.

Pulm. Pharmacol. Ther.

Temporal associations between coughing or wheezing and acid reflux in asthmatics

Gut

Dextromethorphan and codeine: comparison of plasma kinetics and antitussive effects

Eur. J. Respir. Dis.

A new tool to assess and monitor the burden of chronic cough on quality of life: chronic cough impact questionnaire

Allergy

Clinical and physiological studies on the use of metacortandracin in repsiratory disease. 1. Bronchial asthma

Dis. Chest

Chronic tonsillar enlargement and cough: preliminary evidence of a novel and treatable cause of chronic cough

Eur. Respir. J.

Development of a symptom specific health status measure for patients with chronic cough: Leicester cough questionnaire (LCQ)

Thorax

Airway inflammation, airway responsiveness and cough before and after inhaled budesonide in patients with eosinophilic bronchitis

Eur. Respir. J.

Subjective scoring of cough in children: parent-completed vs child-completed diary cards vs an objective method

Eur. Respir. J.

Subjective scoring of cough in children: parent-completed vs child-completed diary cards vs an objective method

Eur. Respir. J.

A randomised, placebo controlled trial of inhaled salbutamol and beclomethasone for recurrent cough

Arch. Dis. Child

Frequency and perception of cough severity

J. Paediatric Child Health

Clinical evaluation of a new antitussive preparation

Ann. Allergy

Sensitivity of the cough reflex in patients with chronic cough

Eur. Respir. J.

Sensitivity of the human cough reflex: effect of inflammatory mediators prostaglandin E2, bradykinin, and histamine

Am. Rev. Respir. Dis.

The clinical and pathophysiological challenege of cough

The Sarcoidosis Health Questionnaire: a new measure of health-related quality of life

Am. J. Respir. Crit. Care Med.

An electromyographic method of objectively assessing cough intensity and use of the method to assess effects of codeine on the dose–response curve to citric acid

Br. J. Clin. Pharm.

Evaluation of an ambulatory system for the quantification of cough frequency in patients with chronic obstructive pulmonary disease

Cough

Bioacoustics of cough during bronchial inhlation challenge (BIC) with methacholine

Eur. Resp. J.

Psychophysical assessment of the urge-to-cough

Eur. Respir. Rev.

Spectral analysis of cough sounds recorded with and without a nose clip

Bull. Eur. Physiopathol. Respir.