Trends and patterns of cause-specific hospitalizations in mainland Portugal between 2000 and 2016.

OBJECTIVES: This study aimed to describe trends and patterns of cause-specific hospitalizations in mainland Portugal between 2000 and 2016. STUDY DESIGN: This was a retrospective observational study based on hospital discharge data during the period 2000-2016 in mainland Portugal. METHODS: All inpatient hospital discharges among mainland Portuguese public hospitals were considered to evaluate trends and patterns over the years through hospitalization proportions, number of hospitalizations, age-standardized hospitalization rates (direct standardization using the European standard population), and the number of in-hospital stay days (bed-days). Health Cost and Utilization Project Clinical Classifications Software was used to categorize and cluster inpatients' principal diagnosis. RESULTS: Between 2000 and 2002 and between 2014 and 2016, age-standardized hospitalization rates decreased by 8.6%. Moreover, "liveborn," "diseases of the heart," and "respiratory infections" were the leading hospitalization causes in both periods with a variation of -8.8%, -8.3%, and 13.4% on age-standardized hospitalization rate, respectively. The age-standardized hospitalization rate due to "bacterial infection" increased by 108.7%. "Respiratory diseases" are the leading cause responsible for more in-hospital stay days in the period 2014-2016 (48.6% increase). All Portuguese regions presented decreasing overall trends in their age-standardized hospitalization rates in the study period, yet increasing trends were observed until 2004 except for the Lisbon region; in addition, the number of in-hospital stay days remained relatively stable through time. CONCLUSIONS: Hospitalizations in mainland Portugal decreased between 2000 and 2016 with heterogeneous patterns considering time, age group, and gender. "Aspiration pneumonitis; food/vomitus," "diseases of the white blood cells," "other nutritional, endocrine, and metabolic disorders," "bacterial infection," and "pathological fractures" revealed substantial increases, and further evaluations and monitoring are required.