BACKGROUND: Few studies have investigated the relationship between physiological outcomes and quality of life in patients with idiopathic pulmonary fibrosis (IPF). Health-related quality of life (HRQL) data may provide a valuable patient-centred outcome for the evaluation of interventions. Determination of which physiological and functional variables are associated with HRQL may facilitate interpretation of disease progression and impacts of therapy.
OBJECTIVES: To determine whether an association between Medical Outcomes Short-Form 36 and St George's Respiratory Questionnaire scores and other markers of disease severity exist, and to identify which physiological and functional variables are independently associated with HRQL.
METHODS: In a cross-sectional study, 137 patients with IPF completed HRQL surveys and underwent clinical assessment. Multiple linear regression analysis was used to determine the relationship between age, forced vital capacity, diffusing capacity of carbon monoxide, 6 min walk distance (6MWD) and oxygen requirement, and HRQL scores.
RESULTS: 6MWD was the only functional measure of disease severity significantly associated with all domain scores of the St George's Respiratory Questionnaire and the Medical Outcomes Short-Form 36 physical component summary score.
CONCLUSIONS: 6MWD was associated with HRQL among patients with IPF. This highlights the importance of 6MWD not only as a prognostic indicator in IPF, but also a predictor of HRQL and a meaningful outcome for patients.