Translation of the Leicester Cough Questionnaire into Swedish, and validity and reliability in chronic obstructive pulmonary disease

Abstract

Purpose: The purpose of this study was to translate and culturally adapt the Leicester Cough Questionnaire into Swedish and to test the validity and reliability of the Swedish version, in patients with chronic obstructive pulmonary disease.

Methods: The original Leicester Cough Questionnaire was translated into Swedish by a method, which followed an established forward-backward procedure, including cross-cultural adaptation and pretest. To test the validity of the final version of Leicester Cough Questionnaire in Swedish, the St George’s Respiratory Questionnaire and the COPD Assessment Test were used (n =112) and to test reliability, the questionnaire was repeated (n = 86).

Results: The Leicester Cough Questionnaire in Swedish showed proof of construct validity and proof of internal consistency (Cronbach’s alpha coefficient 0.97). All domains and total scores had good-excellent test-retest reliability (intra-class correlation coefficient 2,1 > 0.94). The standard error of measurement, (standard error of measurement percent), for the Leicester Cough Questionnaire in Swedish was 0.84 (5.15%). The smallest real difference, (smallest real difference percent), derived from cross sectional standard error of measurement was 2.33 (14.25%). The Bland–Altman plot indicated no systemic change in the mean.

Conclusion: The Leicester Cough Questionnaire in Swedish is a valid and reliable instrument to measure health-related quality of life in patients with chronic obstructive pulmonary disease and can be used in clinical settings.

Implications for Rehabilitation

• The Leicester Cough Questionnaire, has been translated into Swedish, following an established forward-backward procedure, including cross-cultural adaptation

• The Swedish version of the Leicester Cough Questionnaire, is a valid, reliable instrument for measuring health-related quality of life regarding cough in patients with chronic obstructive pulmonary disease

• The Swedish version of the Leicester Cough Questionnaire is easy to administer and can be used in clinical and rehabilitation settings and for research purposes

• The absolute reliability presented at group and individual levels to indicate a real improvement is an advantage to assist when interpreting a clinically relevant difference

Keywords:

• Cross-cultural adaptation
• expert committee
• test-retest
• cough
• forward-backward translation

Acknowledgements

The authors would like to thank all the participants in the study. A special thanks to the translators and the expert committee and colleagues at the Department of Physiotherapy at Karolinska University Hospital in Stockholm.

Disclosure statement

The authors report no conflicts of interest in this work. The authors alone are responsible for the content and writing of the paper.

Additional information

Funding

This work was supported by grants from the Swedish Heart and Lung Association, the Department of Physiotherapy at Karolinska University Hospital in Stockholm and the Mats Kleberg Foundation.