Minimal Clinically Important Differences for Patient-Reported Outcome Measures of Cough and Sputum in Patients with COPD

Abstract

Background

Cough and sputum are highly prevalent in patients with chronic obstructive pulmonary disease (COPD). Pulmonary rehabilitation (PR) has shown to be effective in managing these symptoms. However, the interpretation of the magnitude of PR effects is hindered by the lack of minimal clinically important differences (MCIDs).

Purpose

This study established MCIDs for the Leicester cough questionnaire (LCQ) and the cough and sputum assessment questionnaire (CASA-Q), in patients with COPD after PR.

Patients and Methods

An observational prospective study was conducted in patients with COPD who participated in a 12-weeks community-based PR program. Anchor- (mean change, receiver operating characteristic curves and linear regression analysis) and distribution-based methods [0.5*standard deviation; standard error of measurement (SEM); 1.96*SEM; minimal detectable change and effect size] were used to compute the MCIDs. The anchors used were: i) patients and physiotherapists global rating of change scale, ii) COPD assessment test, iii) St. George’s respiratory questionnaire and iv) occurrence of an exacerbation during PR. Pooled MCIDs were computed using the arithmetic weighted mean (2/3 for anchor- and 1/3 for distribution-based methods).

Results

Forty-nine patients with COPD (81.6% male, 69.8±7.4years, FEV ₁50.4±19.4 _%predicted) were used in the analysis. The pooled MCIDs were 1.3 for LCQ and for CASA-Q domains were: 10.6 - cough symptoms; 10.1 - cough impact; 9.5 - sputum symptoms and 7.8 - sputum impact.

Conclusion

The MCIDs found in this study are potential estimates to interpret PR effects on cough and sputum, and may contribute to guide interventions.

Journal

Journal ID (nlm-ta): Int J Chron Obstruct Pulmon Dis

Journal ID (iso-abbrev): Int J Chron Obstruct Pulmon Dis

Journal ID (publisher-id): COPD

Journal ID (pmc): copd

Title: International Journal of Chronic Obstructive Pulmonary Disease

Publisher: Dove

ISSN (Print): 1176-9106

ISSN (Electronic): 1178-2005

Publication date (Electronic): 29 January 2020

Publication date Collection: 2020

Volume: 15

Pages: 201-212

Affiliations

[1 ]Respiratory Research and Rehabilitation Laboratory (Lab3R), School of Health Sciences, University of Aveiro (ESSUA) , Aveiro, Portugal

[2 ]Institute of Biomedicine, School of Health Sciences (iBiMED), University of Aveiro (ESSUA) , Aveiro, Portugal

[3 ]Pulmonology Department, Centro Hospitalar Do Baixo Vouga (CHBV) , Aveiro, Portugal

Author notes

Correspondence: Alda Marques Escola Superior de Saúde, Universidade de Aveiro - Edifício 30 , Agras do Crasto - Campus Universitário de Santiago, Aveiro3810-193, Portugal Email [e-mail]

Article

Publisher ID: 219480

DOI: 10.2147/COPD.S219480

PMC ID: 6996113

Copyright statement: © 2020 Rebelo et al.

License:

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Page count

Figures: 4, Tables: 3, References: 69, Pages: 12

Categories

Subject: Original Research