Retrospective observational analysis of hospital discharge database to characterize primary pulmonary hypertension and its outcomes in Spain from 2004 to 2015.

To examine trends in the incidence, characteristics and outcomes, and to identify factors associated with in-hospital mortality (IHM) of patients hospitalized for primary pulmonary hypertension (PPH) in Spain (2004-2015).We included all patients hospitalized with PPH and included in the Spanish National Hospital Discharge Database.We analyzed 46,883 discharges of patients (7.14% with PPH as their primary diagnosis). Incidence rates decreased from 6.15 cases per 100,000 inhabitants in 2004-06 to 3.40 in 2013-15 (P < .001). Mean age rose from 66.43 ± 21.28 to 69.73 ± 21.12 years (P < .001) and the proportion of females increased over the study period (58.44% vs 60.71%; P < .001). Comorbidity using the Charlson Comorbidity Index (CCI) also increased with 16.07% having CCI ≥3 in 2004-06 vs 21.795 in 2013-15. Median length of hospital stay (LOHS) was 1 day longer in period 2004-06, than in 2013-15 (9 vs 8 days; P < .001). The proportion of patients who were considered a readmission and the mean costs increased from 15.7% and 3712.46&OV0556; in the first period to 17.14% and 4040.28&OV0556; in 2013-15 (P < .001). IHM increased from 8.2% in 2004-06 to 9.93% in 2013-15 (P < .001). The predictors' of IHM among PPH patients included comorbidity and use of mechanical ventilation. Primary diagnosis of PPH did not predict higher IHM (OR 1.07; 95%CI 09-1.26).Our data indicates that the incidence of hospitalizations decreased in Spain between 2004 and 2015. Parallel, LOHS also decreased during this period. By contrast, comorbidity increased over time in PPH patients, as well as readmission rates, costs and IHM.