In-hospital mortality in co-occurring dehydration and dysphagia: results from the nationwide GEMIDAS Pro registry

Abstract

Abstract Purpose Dehydration is common in older hospitalized adults, but its prognostic relevance and relationship with dysphagia in acute geriatric care remain uncertain. We examined the prevalence, clinical profile, and hospital outcomes of dehydration and whether it was independently associated with in-hospital mortality after accounting for dysphagia. Methods We analyzed data from the GEMIDAS Pro registry on acute geriatric inpatient admissions in Germany between 2006 and 2024. We included admissions aged ≥ 65 years. Dehydration and dysphagia were identified from main or secondary ICD-10-GM diagnoses. Multivariable logistic regression examined factors associated with dehydration and in-hospital mortality. A four-group model assessed mortality according to the separate and combined presence of dysphagia and dehydration. Results Among 1,343,561 admissions, dehydration was documented in 177,091 (13.2%). Admissions with dehydration had lower cognitive and functional status, less functional improvement among survivors, and higher in-hospital mortality than those without dehydration (5.8% vs 2.6%). Dysphagia was independently associated with dehydration. After adjustment including dysphagia, dehydration remained independently associated with in-hospital death (adjusted OR 1.35, 95% CI 1.32–1.38), as did dysphagia (adjusted OR 1.68, 95% CI 1.64–1.73). Mortality increased from 2.2% with neither condition to 4.7% with dehydration alone, 8.6% with dysphagia alone, and 12.1% when both were present. The combined group had the highest adjusted odds of mortality (OR 2.12, 95% CI 2.03–2.21). Conclusion Dehydration was common and associated with adverse hospital outcomes in acute geriatric care. Its overlap with dysphagia identified a vulnerable subgroup and supports combined consideration of swallowing and hydration in clinical care.