Validation of the Spanish Version of the COPD-Q Questionnaire on COPD Knowledge.
RATIONALE
Although recognition of the importance of educating chronic obstructive pulmonary disease (COPD) patients has grown in recent years, their understanding of this disease is not being measured due to a lack of specific instruments. The aim of this study was to validate the COPD-Q questionnaire, a 13-item instrument for determining COPD knowledge.


METHODS
The COPD-Q was translated and backtranslated, and subsequently submitted to logic and content validation by a group of COPD experts and 8 COPD patients. Reliability was studied in an independent group of 59 patients with severe COPD seen in the pulmonology ward or clinics of 6 hospitals in Spain (Andalusia, Baleares, Castilla-La Mancha, Galicia and Madrid). This sample was also used for other internal and external validations.


RESULTS
The mean age of the group was approximately 70 years and their health awareness was low-to-medium. The number of correct answers was 8.3 (standard deviation: 1.9), median 8, range 3-13. Floor and ceiling effects were 0% and 1.5%, respectively. Internal consistency of the questionnaire was good (Cronbach's alpha=0.85) and reliability was also high, with a kappa coefficient >0.6 for all items and an intraclass correlation efficient of 0.84 for the total score.


CONCLUSION
The 13-item COPD-Q is a valid, applicable and reliable instrument for determining patients' knowledge of COPD.