Evaluating the Association Among Demographic, Disease, and Symptom Profiles and Quality of Life in Connective Tissue Disease-Related Interstitial Lung Disease

Abstract

Connective tissue disease-related interstitial lung disease (CTD-ILD) results in an unrelenting symptom burden and may progress to death. The morbidity and mortality associated with CTD-ILD likely has a profound impact on individuals’ quality of life (QOL). Quality of life is a phenomenon that has yet to be sufficiently described in the literature on CTD-ILD. The factors associated with QOL in other chronic lung diseases have been described, but because of the different clinical and demographic characteristics of CTD-ILD, it is unknown if these same factors are associated with QOL in CTD-ILD. The purpose of this study was to examine the QOL and associated factors and potential mediating and moderating effect of symptoms for individuals with CTD-ILD. This was a secondary analysis of data from the Pulmonary Fibrosis Foundation Patient Registry. The aims of this study were to describe the association among CTD-ILD patient demographic, disease characteristics, and QOL and to examine the relationship between symptoms and QOL in CTD-ILD. Additionally, we examined potential mediation and moderation relationships between symptoms and QOL in CTD-ILD. The study aims and hypotheses were informed by the Factors Affecting Quality of Life Model. This model was used to determine if causal relationships among symptoms and QOL exist using path analysis. The results of the study revealed the majority of participants to be female (66%), white (78%), have a disease duration of 1-3 years (30%), the have scleroderma (25%).

The average age was 61 years with a forced vital capacity of 67% predicted. The majority of participants were not on supplemental oxygen (62%), taking immunosuppressive medications (66%), or active in pulmonary rehabilitation (89%). Female gender, lower forced vital capacity, supplemental oxygen use, pulmonary rehabilitation participation, shortness of breath, cough, and fatigue to all be correlated with poorer quality of life. Shortness of breath mediated the relationships between quality of life and the factors of gender, forced vital capacity, supplemental oxygen use, and pulmonary rehabilitation. Fatigue mediated the relationship between quality of life and pulmonary rehabilitation. An understanding of QOL and its associated factors may allow for better tailoring of therapies that can result in improved QOL for individuals with CTD-ILD.