Roy, M.J.

Abstract Rationale: Patients with fibrotic interstitial lung disease (F-ILD) often report high symptom burden with significant impact on their health-related quality of life. Self-reported disease experience may be unique or difficult to quantify yet have implications for functional and survival outcomes. We hypothesize that self-reported mood or affect may be associated with changes in lung function and predict mortality. Methods: This is a post-hoc analysis of a prospective cross-sectional study assessing changes in patient-reported outcome measures (PROM), lung function, and mortality incidence in patients with f-ILD. Serial measures of lung function and PROMs (baseline, 3, 6, and 12 months) were obtained over a 3-year period. The Positive and Negative Affect Scale (PANAS) is a 20-item questionnaire reflecting acute or immediate mood at the time of assessment, with higher scores for each domain highlighting greater positive or negative affect. A ratio of the Positive over the Negative score was used to summarize overall mood, with higher ratios reflecting more positive affect. PANAS scores at the time of lung function measures were assessed for their association with percent predicted forced vital capacity (FVC%) and diffusion capacity for carbon monoxide (DLCO%). Baseline PANAS scores were used to predict of all-cause mortality over the three-year study period. Results: One-hundred and eighty seven patients were included (mean age 69, female 37%, non-IPF f-ILD 67%). PANAS Negative scores were higher (16.9 vs 14.5, P = 0.01)with lower PANAS Ratio scores (2.5 vs 2.2, P = 0.08) in patients with non-IPF f-ILD, suggesting more negative affect or mood. A mixed effects model for repeated measures with each subject as a random effect found changes in the PANAS Positive score (point estimate 0.16, (0.01-0.32), P = 0.038) and Ratio score (1.43 (0.15-2.72), P = 0.029) were associated with changes in FVC% but not DLCO%. Baseline PANAS Negative (hazard ratios 1.06 (1.02-1.10), P = 0.002) and Ratio scores (HR 0.76 (0.61-0.95), P = 0.014) after adjusting for age, sex, FVC%, and diagnosis type (IPF vs non-IPF), were associated with increased all-cause mortality. Conclusions: Measured changes in self-reported mood or affect appear to be associated with changes in lung function and predict all-cause mortality. Direct assessments of patient disease experience may not only reflect symptom burden or disease progression but serve as targets of comprehensive management strategies or correlates of treatment efficacy given their potential association with lung function and survival.