Relationship between age and in-hospital mortality during 15,345,025 non-surgical hospitalizations

INTRODUCTION: Mortality, whether in or out of hospital, increases with age. However, studies evaluating in-hospital mortality in large populations did not distinguish between surgical and non-surgical causes of death, either in young or in elderly patients. The aim of the study was to assess in-hospital non-surgical mortality in a large group of patients, with a special focus on the elderly. MATERIAL AND METHODS: Data from the database of the Polish National Health Fund (NHF) regarding hospitalizations of adult (≥ 18 years) patients not related to surgical procedures in the years 2009-2013 were used to assess in-hospital mortality. RESULTS: 15,345,025 hospitalizations were assessed. The mean in-hospital non-surgery-related mortality rate was 3.96 ±0.17%, and increased from 3.79% to 4.2% between 2009 and 2013. The mean odds ratio for in-hospital death increased with the age of patients, reaching a 229-fold higher rate in the ≥ 95 years age group as compared to the 18-24 age group. The highest mean mortality was associated with respiratory diseases (6.91 ±0.20%), followed by heart and vascular diseases, nervous system diseases, as well as combined gastrointestinal tract, liver, biliary tract, pancreas and spleen diseases (5.65 ±0.27%, 5.46 ±0.05% and 4.01 ±0.13%, respectively). CONCLUSIONS: The in-hospital non-surgery-related mortality rate was approximately 4%. It significantly increased with age and, regardless of age, was highest in patients suffering from respiratory diseases.