HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:
Guest Access | Sign In via User Name/Password

This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Smith, J. Articles by Woodcock, A. Search for Related Content PubMed PubMed Citation Articles by Smith, J. Articles by Woodcock, A.

Cough in COPD^*

Correlation of Objective Monitoring With Cough Challenge and Subjective Assessments

^* From the North West Lung Centre, South Manchester University Hospitals Trust, Manchester; and Aintree Chest Centre, University Hospital Aintree, Liverpool, UK.

Correspondence to: Jaclyn Smith, MD, PhD, North West Lung Research Centre, Wythenshawe Hospital, Southmoor Rd, Wythenshawe, Manchester M23 9LT, UK; e-mail jacky.smith{at}manchester.ac.uk

Abstract

Background: The relationships between objective cough rates, cough reflex sensitivity, subjective estimates of cough frequency, and cough-related quality of life in patients with COPD are poorly understood.

Subjects: Twenty-six patients with stable COPD who complained of cough (76.9% men; mean ± SD age, 68.7 ± 6.9 years; mean FEV₁, 54.2 ± 12.0% of predicted; median smoking history, 42.4 pack-years [range, 13 to 135 pack-years]).

Methods: Subjects performed a cough challenge test, ambulatory daytime and overnight sound recordings, scored the severity of cough (0 to 5 score and visual analog scale) for each recording period, and completed a cough-specific quality of life questionnaire (CQLQ). Coughs were counted manually and quantified in terms of cough seconds per hour (cs/h): the number of seconds within the recording that contain cough.

Results: Overall median time spent coughing was 7.5 cs/h (range, 2.7 to 23.1 cs/h; daytime median, 12.4 cs/h [range, 3.3 to 40.4 cs/h]; overnight, 1.9 cs/h [0.0 to 19.0 cs/h]) [p = <0.01]. Median log concentration of citric acid eliciting five coughs (C5) was – 0.9 mol/L (range, – 1.5 to 0.0 mol/L). Day time but not overnight time spent coughing was significantly correlated with log C5 (log C5 r = – 0.49, p = 0.02, and r = – 0.20, p = 0.37, respectively). Subjective cough scores and visual analog scales were moderately associated with objective time spent coughing: daytime (r = 0.37, p = 0.03, and r = 0.41, p = 0.03) and overnight (r = 0.48, p = <0.01, and r = 0.5, p = 0.01), respectively.

Conclusions: Subjective measures of cough and cough reflex sensitivity are statistically related to time spent coughing in patients with COPD, but with low-to-moderate levels of correlation. These measures have insufficient predictive value to substitute for objective time spent coughing; however, in conjunction with the CQLQ, they may provide a qualitative dimension to the assessment of cough.

Key Words: ambulatory monitoring • chronic bronchitis • citric acid • cough challenge

This article has been cited by other articles:

				S. Decalmer, A. A. Woodcock, J. A. Smith, R. Tutuian, and D. O. Castell Patient Misreporting May Lead to Underestimation of Cough Events Chest, July 1, 2007; 132(1): 358 - 359. [Full Text] [PDF]