Verbal and Visuo-Graphic Measures of Illness Perceptions Predict Quality of Life and Symptoms Among Patients With Interstitial Lung Disease

PURPOSE: Prior research indicates that verbal reports of illness perceptions are associated with quality of life among individuals with interstitial lung disease (ILD). However, individuals with diverse language and verbal abilities may have difficulty providing verbal ratings of illness status. This study evaluated both verbal and visuo-graphic measures of perceived illness as predictors of illness-related quality of life and self-reported pulmonary symptoms among individuals with ILD. METHODS: This was a cross-sectional study in a convenience sample of patients with ILD recruited from a clinic setting. Forty adults (63% female; mean age: 62.8; range: 32-85 years) with ILD completed standard medical evaluations of pulmonary function and exercise capacity. Study participants also completed self-report questionnaires (pulmonary symptoms, illness-related quality of life, and illness perceptions) and the lung coloring task (LCT), a standardized visuo-graphic measure of illness perceptions developed for this study. The primary approach to data analysis was multiple regression analysis predicting illness-related quality of life and self-rated symptoms from pulmonary function, illness perceptions, and LCT. RESULTS: Both forced vital capacity and illness perceptions were significant predictors of illness-related quality of life, accounting for approximately 55% of the variance. The symptom dimension of illness-related quality of life was predicted by forced vital capacity, illness perceptions, and LCT, accounting for approximately 40% of the variance. CONCLUSIONS: Illness perceptions are important for understanding illness-related quality of life among individuals with chronic lung disease. Visuo-graphic measures of illness perceptions may be especially useful for evaluating symptom experiences in chronic lung disease.