Longitudinal Analysis of Causes of Mortality in Continuous Positive Airway Pressure-treated Patients at the Population Level.

Rationale: Randomized controlled trials do not support a role for continuous positive airway pressure (CPAP) in preventing major cardiovascular events or mortality in patients with obstructive sleep apnea (OSA). However, these trials' setting does not apply to most CPAP-treated patients. Objectives: We aimed to assess the effect of CPAP on mortality in real-world patients. Methods: We performed a population-based longitudinal observational study including all patients with OSA prescribed CPAP during 2011 in Catalonia, Spain, and non-OSA control subjects matched (1:2) by sex, 5-year age group, and region who were followed from 2011 to 2016. Results: A total of 9,317 CPAP-treated patients with OSA and 18,370 control subjects without OSA were included (median age, 67 [57-72] years; 74% male). During a median follow-up of 5.5 years, 2,301 deaths were recorded. After adjustment by a composite of diagnosed comorbidities and previous use of healthcare resources, CPAP-treated patients showed a lower risk of death than control subjects (hazard ratio [HR], 0.67; 95% confidence interval [CI], 0.61-0.74), with the association not being statistically significant in women. Cancer-related deaths were the main drivers of this association (men: HR, 0.44; 95% CI, 0.36-0.54; women: HR, 0.44; 95% CI, 0.28-0.68). No significant associations were found for cardiovascular-related deaths. CPAP-treated women had an increased risk of respiratory-related death (HR, 2.41; 95% CI, 1.37-4.23). Conclusions: CPAP-treated patients had a lower mortality rate than control subjects. This relationship was driven by cancer-related, but not cardiovascular-related, deaths. Results suggest a role for sex when prescribing CPAP, especially considering respiratory-related deaths, and foster a debate on the relationship between OSA and cardiovascular outcomes.

Hospitalizations due to exacerbations of COPD: A big data perspective.

BACKGROUND: Patients with Chronic Obstructive Pulmonary Disease (COPD) may suffer episodes of exacerbation (ECOPD) that require hospitalization and worsen their health status, and prognosis. We hypothesized that a detailed interrogation of health-care "big data" databases can provide valuable information to better understand the risk factors and outcomes of these episodes. MATERIAL AND METHODS: We interrogated four databases of the Catalan health-care system (>8,000,000 registries) to identify patients hospitalized because of ECOPD for the first time (index event) between 2010 and 2012. Analysis was carried forward since the index event until the end of 2014 or the death of the patient. The two years that preceded the index event were also investigated. RESULTS: We identified 17,555 patients, (≥50 years of age) hospitalized because of ECOPD (ICD9 v.9 codes at discharge) for the first time between 2010 and 2012. In this population we observed that: (1) 23% of patients die within a year after being discharged from their first ECOPD hospitalization; (2) in the remaining patients, all-cause mortality was related to the number of re-hospitalizations, particularly with early (<30 days) readmissions; (3) despite this being a 'respiratory' cohort, prescription and dispensation of drugs for cardiovascular diseases was higher than for obstructive airway diseases; and, finally, (4) lower winter ambient temperatures are associated with hospital admissions for ECOPD particularly in early re-admitters. CONCLUSIONS: Overall these results indicate under appreciation of the burden of COPD in patients hospitalized for the first time because ECOPD.