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).
OBJECTIVE
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 (c=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, <0.001), with a sensitivity of 71.83% and specificity of 64.24% to discriminate "healthy" smokers from other subgroups.


CONCLUSIONS
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.
Žarko
Ž
Vrbica
Marina
M
Labor
Adrijana
A
Košćec Đuknić
Biserka
B
Radošević-Vidaček
Ivan
I
Gudelj
Slavica
S
Labor
Iva
I
Jurić
Peter Ma
PM
Calverley
Davor Plavec, Head of Research Department, Children's Hospital Srebrnjak, Srebrnjak 100, 10000 Zagreb, Croatia, plavec@bolnica-srebrnjak.hr.
Davor
D
Plavec
D000368:Aged; D042241:Early Diagnosis; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology*; D011788:Quality of Life; D012372:ROC Curve; D015203:Reproducibility of Results; D012907:Smoking / Q000453:epidemiology*; D011795:Surveys and Questionnaires / Q000592:standards*