Copyright ©ERS Journals Ltd 2008 The responsiveness and validity of the CAMPHOR Utility Index1 Galen Research, Manchester, 2 School of Psychology, University of Central Lancashire, Preston, 3 Pulmonary Vascular Disease Unit, Papworth Hospital NHS Trust, Papworth Everard, 4 Dept of Cardiology, Royal Free Hospital, 5 Dept of Cardiology, Hammersmith Hospital, and 6 Actelion Pharmaceuticals UK, London, UK. CORRESPONDENCE: D. M. Meads, Galen Research, Enterprise House, Manchester Science Park, Manchester, M15 6SE, UK. Fax: 44 1612264478. E-mail: david_meads{at}hotmail.com Keywords: Bosentan, Cambridge Pulmonary Hypertension Outcome Review, pulmonary hypertension, quality of life, responsiveness, utility
Received: May 6, 2008
The aim of the present study was to validate and determine the mininal important difference (MID) and responsiveness of the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) Utility Index, a new tool enabling cost utility analyses.
CAMPHOR, 6-min walking test (6MWT) and New York Heart Association (NYHA) data for 869 pulmonary hypertension patients (545 (63%) female; mean±SD age 56.6±15.4 yrs) from three centres were analysed. Utility was correlated with 6MWT data and calculated by NYHA class to assess validity. Effect sizes were calculated for those with two CAMPHOR assessments. Distribution and anchor-based MIDs were calculated. Analyses were carried out in patients receiving bosentan in order to determine whether or not those remaining in NYHA class III following treatment improved.
The Utility Index distinguished between adjacent NYHA classes and correlated with 6MWT results. CAMPHOR subscales and utility were as responsive as the 6MWT (effect sizes ranged 0.31–0.69 for the CAMPHOR and 0.16–0.34 for the 6MWT). The within-group MID for the Utility Index was estimated to be
The CAMPHOR Utility Index is valid and responsive to change. Patients can experience significant and important improvements even if they do not improve on the basis of traditional outcomes, such as NYHA functional class.
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