Prognostic value of health-related quality of life in patients with acute dyspnoea: a cohort study

Background: Self-reported health-related quality of life is an established prognostic tool in stable outpatients. However, its prognostic relevance in patients presenting with an acute onset of symptoms such as acute dyspnoea is largely unknown. Methods: This major unmet clinical need was addressed in a secondary analysis of a prospective study, enrolling patients presenting with acute dyspnoea to the emergency departments of two university hospitals in Switzerland. Self-reported health-related quality of life was obtained at presentation with the use of the generic EQ-5D tool and directly compared to the objective risk prediction marker N-terminal pro-B-type natriuretic peptide (NT-proBNP). The primary endpoint was all-cause mortality within 90 and 720 days. Cox proportional hazard regressions were performed with age, sex, history of heart failure, systolic blood pressure, haemoglobin, estimated glomerular filtration rate and NT-proBNP as predictors. Prognostic accuracies were calculated with the use of area under the receiver operating characteristics curve (AUC). Results: Among 1144 eligible patients (median age 74 years, 42% women, 52% acute heart failure), 7% died within 90 days and 28% within 720 days after presentation to the emergency department. The EQ-5D index was strongly associated with mortality. In adjusted Cox regression analyses, the hazard ratios of the EQ-5D index for 90- and 720-day mortality were 7.8 (95% confidence interval CI 3.4-17.9) and 5.0 (95% CI 3.3-7.6), respectively. Prognostic accuracies of the EQ-5D index for 90- and 720-day mortality were 0.68 and 0.65, and comparable to the prognostic accuracy of NT-proBNP (both AUCs: 0.69, p-value for comparison 0.915 and 0.121). Conclusions: Self-reported health-related quality of life assessed by the generic EQ-5D tool provides moderate-to-high prognostic accuracy in patients presenting with acute dyspnoea to the emergency department and may aid physicians in risk stratification. Trial registration: https://clinicaltrials.gov NCT01831115.