PURPOSE: Quality of life (QOL) or health-related quality of life (HRQL) in patients with IPF is reportedly significantly associated with the degree of breathlessness in daily living. HRQL gradually worsens as the disease progress, because dyspnea is also progressive in IPF. However, it is still unknown whether HRQL score would predict mortality in patients with IPF.
METHODS: Eighty-seven consecutive patients with IPF, who had undergone evaluations and complete the St. George’s Respiratory Questionnaire (SGRQ) at diagnosis, as is the general practice in Tosei General Hospital, were included in this study. Univariate and multivariate Cox proportional hazards analysis were performed to clarify the relationship between their HRQL score and survival.
RESULTS: The mean observation period was 44.2±29.6 mo. In this observation period, 49 patients (56.3%) died due to respiratory failure in 18 (20.7%), acute exacerbation of IPF in 12 (13.8%), cancer in 5 (5.7%), pneumonia in 3 (3.4%), other cause in 4 (4.6%), and unknown causes in 4 (4.6%). Univariate regression analysis revealed that FVC percentage predictive (HR: 0.970, 95% CI: 0.954-0.987, P=0.0004), DLco percentage predictive (0.982, 0.968-0.996, 0.01), baseline PaO2 (0.970, 0.946-0.996, 0.02), and the activity score in the SGRQ (1.016, 1.004-1.029, 0.01) were revealed to be significantly predictive of survival. The symptoms, the impacts, and the total score in the SGRQ were not significantly related to mortality. In multivariate analysis, however, only FVC percentage predictive was significant predictor of survival (0.975, 0.955-0.996, 0.02).
CONCLUSION: Although the activity score in the SGRQ was significantly related to mortality, it was not significant after an adjustment for FVC, DLco, and PaO2. Mortality cannot be predicted from the HRQL scores in IPF.
CLINICAL IMPLICATIONS: Given that worse HRQL is not necessarily related to worse survival in IPF, HRQL is considered to be another aspect from physical impairment.
DISCLOSURE: Osamu Nishiyama, No Financial Disclosure Information; No Product/Research Disclosure Information