Predictors of deterioration of symptoms and quality of life in patients with sarcoidosis

Abstract

Introduction. The most frequent clinical outcomes in sarcoidosis patients are typically focused on the objective measurements of functions of the involved organs, but, generally, they do not take into account the individual perception of patients? everyday functioning. The aim of this study was to determine the type of association between the subjective disease outcomes and other objective conventional parameters in patients with sarcoidosis. Material and Methods. In the cross-sectional study including 172 sarcoidosis patients (122 females), quality of life was measured by a generic instrument, i.e. fifteen-dimensional measure of health-related quality of life together with a respiratory specific instrument, i.e. St George?s Respiratory Questionnaire; symptoms of fatigue were measured by Fatigue Scale and dyspnea was measured by the Basal Dyspnea Index. Body-mass index and the course of the disease (acute vs. chronic) were also evaluated. Pulmonary function was assessed by spirometry. Results. Acute sarcoidosis was present in 48 (28%) patients. Mean body mass index was 27.01?5.2. Only 20 (12%) patients had lower forced expiratory volume in one second values (<80%) that indicated the existance of obstructive ventilatory impairment. Multivariate linear regression analysis revealed that body mass index, clinical course of disease and spirometric parameter forced expiratory volume in one second were the significant predictors (R2=0.929, p<0.01) of sarcoidosis related fatigue (B=0.061, B=0.406, B=0.452; respectively). Body mass index and forced expiratory volume in one second were the only parameters that significantly predicted both patients? quality of life (R2=0.932; B=0.017, B=0.263) and dyspnea (R2=0.847; B=0.025, B=0.668). Conclusions. It is important to measure both subjective patient-reported outcomes and objective disease parameters in sarcoidosis since they represent different aspects of the disease. All applied measuring instruments for the examined subjective outcomes demonstrated good measuring properties.