title: The Assessment of Burden of COPD (ABC) Scale: A Reliable and Valid Questionnaire.
abstract: The newly developed Assessment of Burden of COPD (ABC) scale is a 14-item self-administered questionnaire which measures the physical, psychological, emotional and/or social burden as experienced by patients with chronic obstructive pulmonary disease (COPD). The ABC scale is part of the ABC tool that visualises the outcomes of the questionnaire. The aim of this study was to assess the reliability and construct validity of the ABC scale. This multi-centre survey study was conducted in the practices of 19 general practitioners and 9 pulmonologists throughout the Netherlands. Next to the ABC scale, patients with COPD completed the Saint George Respiratory Questionnaire (SGRQ). Reliability analyses were performed with data from 162 cases. Cronbach's alpha was 0.91 for the total scale. Test-retest reliability, measured at a two week interval (n = 137), had an intra-class correlation coefficient of 0.92. Analyses for convergent validity were performed with data from 133 cases. Discriminant and known-groups validity was analysed with data from 162 cases. The ABC scale total score had a strong correlation with the total score of the SGRQ (r = 0.72, p < 0.001) but a weak correlation with the forced expired volume in 1 second predicted (r = -0.28, p < 0.001). Subgroups with more severe disease, defined by GOLD-stage, frequency of exacerbations, activity level and depression scored statistically significantly (p < 0.05) worse on almost all domains of the ABC scale than the less severe subgroups. The ABC scale seems a valid and reliable tool with good discriminative properties.
authors.affiliation: a Department of Family Medicine , Maastricht University, CAPHRI School for Public Health and Primary Care , MD Maastricht , The Netherlands.
authors.forename: Annerika H M
authors.initials: AH
authors.lastname: Slok
authors.affiliation: a Department of Family Medicine , Maastricht University, CAPHRI School for Public Health and Primary Care , MD Maastricht , The Netherlands.
authors.forename: Thomas C H
authors.initials: TC
authors.lastname: Bemelmans
authors.affiliation: a Department of Family Medicine , Maastricht University, CAPHRI School for Public Health and Primary Care , MD Maastricht , The Netherlands.|h Institute of General Practice , Medical Faculty of the Heinrich-Heine-University Düsseldorf , Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kotz
authors.affiliation: b Department of Primary Care , University of Groningen, University Medical Centre Groningen , Groningen , The Netherlands.|c Groningen Research Institute for Asthma and COPD (GRIAC) , University Medical Centre , Groningen , The Netherlands.
authors.forename: Thys
authors.initials: T
authors.lastname: van der Molen
authors.affiliation: c Groningen Research Institute for Asthma and COPD (GRIAC) , University Medical Centre , Groningen , The Netherlands.|d Department of Pulmonary Diseases , University of Groningen, University Medical Centre Groningen , Groningen , The Netherlands.
authors.forename: Huib A M
authors.initials: HA
authors.lastname: Kerstjens
authors.affiliation: e Department of Pulmonology , Sint Franciscus Gasthuis , Rotterdam , The Netherlands.
authors.forename: Johannes C C M
authors.initials: JC
authors.lastname: In 't Veen
authors.affiliation: f Department of Public Health and Primary Care , Leiden University Medical Centre , Leiden , The Netherlands.
authors.forename: Niels H
authors.initials: NH
authors.lastname: Chavannes
authors.affiliation: a Department of Family Medicine , Maastricht University, CAPHRI School for Public Health and Primary Care , MD Maastricht , The Netherlands.
authors.forename: Guus M
authors.initials: GM
authors.lastname: Asijee
authors.affiliation: g Erasmus University Rotterdam , Institute for Health Policy and Management / Institute for Medical Technology Assessment , Rotterdam , The Netherlands.
authors.forename: Maureen P M H
authors.initials: MP
authors.lastname: Rutten-van Mölken
authors.affiliation: a Department of Family Medicine , Maastricht University, CAPHRI School for Public Health and Primary Care , MD Maastricht , The Netherlands.
authors.forename: Onno C P
authors.initials: OC
authors.lastname: van Schayck
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D017281:Cost of Illness; D003863:Depression / Q000523:psychology*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology* / Q000523:psychology; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
keywords: burden of disease; integrated health status; reliability; validity