Hospital admissions of children under 5 years old in Portugal (june 2010 – july 2021)

Abstract Background Pediatric hospitalizations are an indicator of child morbidity. In 2020, a 29% decrease was recorded among children under 5 in public hospitals, yet long-term trends in Portugal remain underreported. This study explores pediatric admissions between July 1, 2010, and June 30, 2021, examining their frequency, duration, main causes, and distribution by sex, age, and region. Methods A historical cohort study including all children born in Portugal during the study period with hospitalizations in public hospitals. Children were followed until age 5 or the end of the study. Demographic and clinical data were analyzed. Time at risk was calculated based on days of life until hospitalization, end of follow-up, or both. Statistical analysis included descriptive measures and inferential tests. Results Between July 2010 and June 2021, 543,154 hospitalizations were recorded among 395,873 children under 5 in Portugal, averaging 1.4 hospitalizations per child. Admissions increased over time, especially in winter. Most occurred in the perinatal period (85%) and among infants under 1 year (1.4 per child). Boys accounted for 53% of cases and had slightly higher rates than girls (1.4 vs. 1.3; p < 0.01). Lisbon (25.2%) and Porto (13.8%) recorded the highest numbers of hospitalizations, while Vila Real (1.58) and Évora (1.51) had the highest averages per child. The leading causes were perinatal conditions (56%), external causes (18.8%), congenital anomalies (6.9%), and respiratory diseases (4.9%), the latter more common in boys (5.1%) and in children under one (36.7%). The average hospital stay was 4.8 days, longer in neonates (7.5 days) and for eye diseases (26.7 days). Each child was at risk for an average of 2.19 days (SD = 1.05). The overall incidence rate was 0.62 hospitalizations per 1,000 days of life, or 0.23 per child-year. Conclusions Analyzing pediatric hospitalizations helps identify morbidity patterns and guides prevention strategies and pediatric healthcare planning. Key messages • Tracking pediatric hospitalizations reveals key morbidity patterns and supports better planning and prevention in early childhood healthcare. • Most hospitalizations occur in the first year of life, with regional and sex-based differences highlighting the need for targeted pediatric health strategies.