Development and the initial validation of a new self-administered questionnaire for an early detection of health status changes in smokers at risk for chronic obstructive pulmonary disease (MARKO questionnaire)

AIM: To develop and do an initial validation of a new simple tool (self-administered questionnaire) that would be sensitive and specific enough to detect early changes in smokers leading to future development of chronic obstructive pulmonary disease (COPD). METHODS: 224 consecutive participants (50.9% women), with mean ± standard deviation age of 52.3 ± 6.7 years, 37.5 ± 16.7 pack-years smoking history (85.8% active smokers), and no prior diagnosis of COPD were recruited. The MARKO questionnaire was self-administered twice; at the general practitioner's office and after 2-4 weeks at the tertiary care hospital. Participants were assessed for COPD by a pulmonologist after filling in a quality of life (QoL) questionnaires, history-taking, physical examination, lung function test, 6-minute walk test, and laboratory tests. They were divided into four subgroups: “healthy” smokers, symptomatic smokers, and smokers with mild and moderately severe COPD. RESULTS: Psychometric analyses indicated that the 18-item questionnaire had a very good internal consistency (Cronbach’s alpha = 0.91) and test-retest reliability for a four week period (ρc = 0.89, 95% confidence interval [CI] 0.85-0.92, Lin’s concordance). A significant correlations of MARKO scores were found with two QoL questionnaires; r = 0.69 (P < 0.001) and r = 0.81 (P < 0.001). Receiver operating characteristic curve analysis showed an area under the curve of 0.753 (95% CI 0.691-0.808, P < 0.001), with a sensitivity of 71.83% and specificity of 64.24% to discriminate “healthy” smokers from other subgroups. CONCLUSION: Based on psychometric analyses and high convergent validity correlation with already validated QoL questionnaires, the newly developed MARKO questionnaire was shown to be a reliable self-administered short health status assessment tool. TRIAL REGISTRATION: Clinicaltrial.gov NCT01550679