Clinical variables impacting on the estimation of utilities in chronic obstructive pulmonary disease.
OBJECTIVE
Health utilities are widely used in health economics as a measurement of an individual's preference and show the value placed on different health states over a specific period. Thus, health utilities are used as a measure of the benefits of health interventions in terms of quality-adjusted life years. This study aimed to determine the demographic and clinical variables significantly associated with health utilities for chronic obstructive pulmonary disease (COPD) patients.


METHODS
This was a multicenter, observational, cross-sectional study conducted between October 2012 and April 2013. Patients were aged ≥40 years, with spirometrically confirmed COPD. Utility values were derived from the preference-based generic questionnaire EQ-5D-3L applying weighted Spanish societal preferences. Demographic and clinical variables associated with utilities were assessed by univariate and multivariate linear regression models.


RESULTS
Three hundred and forty-six patients were included, of whom 85.5% were male. The mean age was 67.9 (standard deviation [SD] =9.7) years and the mean forced expiratory volume in 1 second (%) was 46.2% (SD =15.5%); 80.3% were former smokers, and the mean smoking history was 54.2 (SD =33.2) pack-years. Median utilities (interquartile range) were 0.81 (0.26) with a mean value of 0.73 (SD =0.29); 22% of patients had a utility value of 1 (ceiling effect) and 3.2% had a utility value lower than 0. The factors associated with utilities in the multivariate analysis were sex (beta =-0.084, 95% confidence interval [CI]: -0.154; -0.013 for females), number of exacerbations the previous year (-0.027, 95% CI: -0.044; -0.010), and modified Medical Research Council Dyspnea Scale (mMRC) score (-0.123 [95% CI: -0.185; -0.061], -0.231 [95% CI: -0.301; -0.161], and -0.559 [95% CI: -0.660; -0.458] for mMRC scores 2, 3, and 4 versus 1), all P<0.05.


CONCLUSIONS
Multivariate analysis showed that female sex, frequent exacerbations, and an increased level of dyspnea were the main factors associated with reduced utility values in patients with COPD.
Pneumology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain ; CIBER de Enfermedades Respiratorias (CIBERES), Tres Cantos, Madrid, Spain.
Marc
M
Miravitlles
Market Access Department, GlaxoSmithKline, Tres Cantos, Madrid, Spain.
Alicia
A
Huerta
Pneumology Department, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Spain.
Manuel
M
Valle
Pneumology Department, Hospital Universitario de la Plana, Vila-real, Castellón, Spain.
Patricia
P
García-Sidro
Health Economics and Outcome Strategies Department, Oblikue Consulting, Barcelona, Spain.
Carles
C
Forné
Health Economics and Outcome Strategies Department, Oblikue Consulting, Barcelona, Spain ; Statistics Department, University of Barcelona, Barcelona, Spain.
Carlos
C
Crespo
CIBER de Enfermedades Respiratorias (CIBERES), Tres Cantos, Madrid, Spain ; Unidad Médico Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío, Universidad de Sevilla, Sevilla, Spain.
José Luis
JL
López-Campos
D000368:Aged; D003430:Cross-Sectional Studies; D018450:Disease Progression; D004417:Dyspnea / Q000175:diagnosis; D005260:Female; D005541:Forced Expiratory Volume; D006295:Health Resources / Q000706:statistics & numerical data*; D006304:Health Status; D006801:Humans; D016014:Linear Models; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology / Q000628:therapy; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D012737:Sex Factors; D013030:Spain; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome; D014797:Vital Capacity
COPD; health utility; health-related quality of life; multivariate linear regression