Psychometric performance of the CAMPHOR and SF-36 in pulmonary hypertension
1 Galen Research Ltd, Manchester, United Kingdom
2 Royal Perth Hospital, Perth, Australia
3 Lung Institute of Western Australia, Centre for Asthma, Allergy and Respiratory Research, University of Western Australia, Crawley, Australia
4 School of Physiotherapy and Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
5 Discipline of Physiotherapy, Faculty of Health Sciences, The University of Sydney, Darlington, Australia
6 Sir Charles Gairdner Hospital, Perth, Australia
7 School of Medicine and Pharmacology, University of Western Australia, Perth, Australia
8 School of Medicine, University of Notre Dame, Fremantle, Australia
BMC Pulmonary Medicine 2013, 13:45 doi:10.1186/1471-2466-13-45Published: 12 July 2013
The Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) and the Medical Outcomes Study Short Form 36 (SF-36) are widely used to assess patient-reported outcome in individuals with pulmonary hypertension (PH). The aim of the study was to compare the psychometric properties of the two measures.
Participants were recruited from specialist PH centres in Australia and New Zealand. Participants completed the CAMPHOR and SF-36 at two time points two weeks apart. The SF-36 is a generic health status questionnaire consisting of 36 items split into 8 sections. The CAMPHOR is a PH-specific measure consisting of 3 scales; symptoms, activity limitations and needs-based QoL. The questionnaires were assessed for distributional properties (floor and ceiling effects), internal consistency (Cronbach's alpha), test-retest reliability and construct validity (scores by World Health Organisation functional classification).
The sample comprised 65 participants (mean (SD) age = 57.2 (14.5) years; n(%) male = 14 (21.5%)). Most of the patients were in WHO class 2 (27.7%) and 3 (61.5%). High ceiling effects were observed for the SF-36 bodily pain, social functioning and role emotional domains. Test-retest reliability was poor for six of the eight SF-36 domains, indicating high levels of random measurement error. Three of the SF-36 domains did not distinguish between WHO classes. In contrast, all CAMPHOR scales exhibited good distributional properties, test retest reliability and distinguished between WHO functional classes.
The CAMPHOR exhibited superior psychometric properties, compared with the SF-36, in the assessment of PH patient-reported outcome.