Validation of a health-related quality of life instrument for primary ciliary dyskinesia (QOL-PCD)
Leigh, Margaret W.
Dell, Sharon D.
Dunn Galvin, Audrey
Quittner, Alexandra L.
Lucas, Jane S.
BMJ Publishing Group
Background: Quality of life (QOL)-primary ciliary dyskinesia (PCD) is the first disease-specific, health-related QOL instrument for PCD. Psychometric validation of QOL-PCD assesses the performance of this measure in adults, including its reliability, validity and responsiveness to change. Methods: Seventy-two adults (mean (range) age: 33 years (18–79 years); mean (range) FEV1% predicted: 68 (26–115)) with PCD completed the 49-item QOL-PCD and generic QOL measures: Short-Form 36 Health Survey, Sino-Nasal Outcome Test 20 (SNOT-20) and St George Respiratory Questionnaire (SGRQ)-C. Thirty-five participants repeated QOL-PCD 10–14 days later to measure stability or reproducibility of the measure. Results: Multitrait analysis was used to evaluate how the items loaded on 10 hypothesised scales: physical, emotional, role and social functioning, treatment burden, vitality, health perceptions, upper respiratory symptoms, lower respiratory symptoms and ears and hearing symptoms. This analysis of item-to-total correlations led to 9 items being dropped; the validated measure now comprises 40 items. Each scale had excellent internal consistency (Cronbach's α: 0.74 to 0.94). Two-week test–retest demonstrated stability for all scales (intraclass coefficients 0.73 to 0.96). Significant correlations were obtained between QOL-PCD scores and age and FEV1. Strong relationships were also found between QOL-PCD scales and similar constructs on generic questionnaires, for example, lower respiratory symptoms and SGRQ-C (r=0.72, p<0.001), while weak correlations were found between measures of different constructs. Conclusions: QOL-PCD has demonstrated good internal consistency, test–retest reliability, convergent and divergent validity. QOL-PCD offers a promising tool for evaluating new therapies and for measuring symptoms, functioning and QOL during routine care.
QOL-PCD , Primary ciliary dyskinesia (PCD) , Psychometric validation , Genetic disorder , Treatment strategies
Behan, L., Leigh, M. W., Dell, S. D., Dunn Galvin, A., Quittner, A. L. and Lucas, J. S. (2017) 'Validation of a health-related quality of life instrument for primary ciliary dyskinesia (QOL-PCD)', Thorax, 72(9), pp. 832-839. doi: 10.1136/thoraxjnl-2016-209356
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