Cluster Analysis of Home Mechanical Ventilation in COPD Patients: A Picture of the Real World and Its Impact on Mortality

Background: Treatment of chronic hypercapnic failure in COPD patients with home noninvasive ventilation (HNIV) remains unclear. Aim: To create a curated cohort of all COPD patients on HNIV in Catalonia, perform a cluster analysis, and evaluate mortality evolution. Study design and methods: This study was a multicenter, observational study including all COPD patients on HNIV on 1st January of 2018. Patients were selected through the Catalan Health Service, and administrative and clinical data were obtained in the previous four years. Principal component analysis of mixed data and hierarchical clustering were performed to identify clusters of patients. Mortality was evaluated from 1 January 2018 until 31 December 2020. Results: A total of 247 patients were enrolled. They were mostly male (78.1%), with a median (SD) age of 70.4 (9.4) years old. In 60%, 55% and 29% of patients, obesity, sleep apnea and heart failure coexisted, respectively. Cluster analysis identified four well-differentiated groups labeled for their clinical characteristics: (1) obese smokers, (2) very severe COPD, (3) sleep apnea and (4) older comorbid males. Patients belonging to Clusters (2) and (4) had a worse prognosis than patients in Clusters (1) and (3). Interpretation: A high heterogeneity in the prescription of HNIV was demonstrated. Cluster analysis identifies four different groups, of which only one had COPD as the main cause of ventilation, while the other three clusters showed a predominance of other comorbidities. This leads to different survival outcomes, including an overlapping phenotype of obesity-related disease and sleep apnea with better survival.