The validity and precision of the Leicester Cough Questionnaire in COPD patients with chronic cough

Health Qual Life Outcomes. 2012 Jan 9;10:4. doi: 10.1186/1477-7525-10-4.

Abstract

Background: A validated instrument to assess the effects of chronic cough on health status in patients with chronic obstructive pulmonary disease (COPD) is currently not available. The Leicester Cough Questionnaire (LCQ) is a cough-specific health status questionnaire which is originally validated for a population of general patients presenting with chronic cough. We examined the psychometric performance of the LCQ in patients with COPD and chronic productive cough.

Methods: Concurrent validity, internal consistency, reproducibility and responsiveness were determined. The St. George's Respiratory Questionnaire (SGRQ) and the Short Form-36 (SF-36) were used as external criteria. Questionnaires were completed at the start of the study. After 2 and 12 weeks the LCQ was repeated, together with a global rating of change.

Results: In total 54 patients were included. Concurrent validity analysis showed significant correlations between corresponding domains of the LCQ and the SGRQ (r(s) -0.31 to -0.60). Corresponding domains of the LCQ and the SF-36 showed weaker correlations (r(s) 0.04 to 0.41). Internal consistency was adequate for two of the three domains (Cronbach's α 0.74 - 0.86). Test-retest reliability in stable patients was high (intraclass correlation coefficients 0.79 - 0.93). The mean difference after two weeks was 0.73 (± 1.75). Responsiveness analysis indicated that the LCQ was able to detect changes after 12 weeks.

Conclusion: The LCQ is a valid, reliable, responsive instrument to measure health status in COPD patients with chronic productive cough.

Trial registration: ClinicalTrials.gov: NCT01071161.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Age Factors
  • Azithromycin / therapeutic use*
  • Chronic Disease
  • Cough / complications
  • Cough / diagnosis
  • Cough / drug therapy*
  • Dose-Response Relationship, Drug
  • Drug Administration Schedule
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Pulmonary Disease, Chronic Obstructive / complications
  • Pulmonary Disease, Chronic Obstructive / diagnosis
  • Pulmonary Disease, Chronic Obstructive / drug therapy*
  • Reproducibility of Results
  • Risk Factors
  • Sex Factors
  • Surveys and Questionnaires / standards*
  • Treatment Outcome

Substances

  • Azithromycin

Associated data

  • ClinicalTrials.gov/NCT01071161