Hospitalisation with community-acquired pneumonia among patients with type 2 diabetes: an observational population-based study in Spain from 2004 to 2013

OBJECTIVES To describe trends in the incidence and outcomes of community-acquired pneumonia (CAP) hospitalisations among patients with or without diabetes in Spain (2004-2013). DESIGN Retrospective, observational study using the Spanish National Hospital Discharge Database (Conjunto Mínimo Básico de Datos (CMBD)). SETTING Spain. PARTICIPANTS We used national hospital discharge data to select all hospital admissions for CAP. MAIN OUTCOME MEASURES Incidence was calculated overall and stratified by diabetes status: type 2 diabetes mellitus (T2DM) and no diabetes. RESULTS We identified 901 136 admissions for CAP (24.8% with T2DM). Incidence rates of CAP increased significantly in patients with T2DM over time. The incidence was higher among people with T2DM for all time periods. Patients with T2DM were older and had higher comorbidity index than non-diabetics. Streptococcus pneumoniae decreased over time for both groups. Time trend analyses showed significant decreases in mortality during admission for CAP for patients with and without T2DM. Factors associated with higher mortality in both groups included: older age, higher comorbidity, mechanical ventilation, red cell transfusion, readmission and Staphylococcus aureus detection. Diabetes was associated with a lower in-hospital mortality (OR 0.92, 95% CI 0.91 to 0.94) after a CAP hospitalisation. CONCLUSIONS CAP incidence rates were higher and increased over time at a higher rate among patients with T2DM. Mortality decreased over time in all groups. The presence of diabetes is not a risk factor for death during admission for CAP.