Background: Pleural empyema (PE) is a major cause of morbidity and mortality worldwide. This study aimed to analyze the epidemiological characteristics of patients hospitalized for PE in Spain between 2016 and 2022. Methods: This retrospective observational study of PE cases was based on the hospital discharge records from the National Health System between 2016 and 2022. The variables analyzed were sex, age, comorbidities, discharge diagnoses and procedures, overall severity, whether empyema was a primary or secondary diagnosis, admission to the intensive care unit (ICU), length of stay (LOS), in-hospital mortality, and healthcare costs. Results: Between 2016 and 2022, 19864 PE cases were diagnosed in Spain, revealing an overall rate of 0.64 per 1000 hospitalizations, with the exception of a slight decline in 2021. The mean age of the patients with PE was 61 years, and 73.85% were men. Most patients had low comorbidities, with a median Charlson comorbidity index (CCI) of 1.7. Most cases (63%) involved secondary diagnoses (pneumonia, pneumococcal pneumonia, sepsis, COVID, or lung cancer). The in-hospital mortality rate was higher in the secondary diagnosis group than in the primary diagnosis group (13.4% vs. 6.2%, respectively, p < 0.001). The factors associated with increased mortality included older age (≥66 years), higher CCI scores, ICU admission, and shorter LOS (<10 days). Conversely, pleural drainage and pneumonia as secondary diagnoses were protective factors. Conclusions: PE is an increasingly common pathology in clinical practice, especially in older and frail patients. It is associated with high morbidity and mortality, and its prognosis worsens with age and comorbidities. Therefore, early and appropriate diagnosis and standardized management strategies are required to mitigate the mortality and healthcare costs.

Background: COPD remains a leading cause of hospitalization and mortality worldwide. This study aimed to analyze trends in COPD patients in Spain from 2016 to 2023, compare outcomes between patients with COPD as a primary versus secondary diagnosis, and identify factors associated with in-hospital mortality. Methods: Retrospective observational study using the Spanish database CMBD. 711.799 patients were analyzed. Demographic characteristics, Charlson Comorbidity Index (CCI), complications, mortality, and hospitalization costs were also evaluated. Multivariate logistic regression was used to identify mortality risk factors. Results: The overall hospitalization rate was 20.02 per 1000 admissions. It decreased by 30% during 2020–2021 before rebounding to peak levels in 2023. The proportion of female patients increased from 19.9% (2016) to 26.4% (2023). Patients with COPD as a secondary diagnosis had higher mortality (13% vs. 5.4%, p < 0.001), greater comorbidity burden (mean CCI 3.5 vs. 2.8), and higher costs. While overall admissions dropped in 2020, mortality peaked at 11.7%, and the number of patients with extremely severe disease nearly doubled. Independent risk factors for mortality included sepsis, age ≥ 66 years, CCI ≥ 3, and COVID-19. Conclusions: Hospitalization involving COPD in Spain showed pandemic-related fluctuations with increasing clinical complexity and increasing female sex. The higher mortality and cost associated with secondary COPD diagnosis highlight the need for comprehensive risk stratification of comorbid conditions and multidisciplinary management of these patients. Early identification of sepsis and CCI scores is essential to improve clinical outcomes in the aging population.