Influence of hospital adverse events and previous diagnoses on hospital care cost of patients with hip fracture.

Previous diagnoses of patients with hip fracture influence the hospitalization cost of these patients, either directly or by increasing the risk of in-hospital adverse events associated with increased costs.
Purpose: To investigate how previous diagnoses influence the occurrence of in-hospital adverse events and how both factors impact on hospital costs.
Methods: This is a retrospective analysis of the hospital Minimum Basic Data Set. Patients aged 70 years or older admitted for hip fracture (HF) at a single University Hospital between January 2012 and December 2016. Both, previous diagnoses and adverse events, were defined according to the International Classification of Diseases (ICD-9/ICD-10). The anticipated cost of each admission was calculated based on diagnosis-related groups and using the "all patients refined" method (APR-DRG). The occurrence of adverse events during hospital stay was assessed by excluding all diagnoses present on admission.
Results: The record included 1571 patients with a mean (SD) age of 84 years. The most frequent previous diagnoses were diabetes (n = 432, 27.5%) and dementia (n = 251, 16.0%), and the most frequent adverse events were delirium (n = 238, 15.1%) and anemia (n = 188, 12.0%). The mean (SD) total acute care costs per patient were €8752.1 (1864.4). The presence of heart failure, COPD, and kidney disease at admission significantly increased the hospitalization cost. In-hospital adverse events of delirium, cardiac events, anemia, urinary tract infection, and digestive events significantly increased costs. The multivariate analyses identified kidney disease as a previous diagnosis significantly contributing to explain an increase in hospitalization costs, and delirium, cardiac disease, anemia, urinary infection, respiratory event, and respiratory infection as in-hospital adverse events significantly contributing to an increase of hospitalization costs.
Conclusions: Although few baseline comorbidities have a direct impact on hospitalization costs, most previous diagnoses increase the risk of in-hospital adverse events, which ultimately influence the hospitalization cost.