Risk factors for in-hospital mortality in patients with dementia

To examine the in-hospital mortality rate, and its risk factors, for patients with dementia admitted to hospital.

We constructed an observational cohort study through data linkage of three Dutch national registers: the hospital discharge register (HDR), the population register (PR) and the national cause of death register. Patients with dementia in the HDR aged between 60 and 100 years registered between 1 January 2000 and 31 December 2010 were included.

Risk factors for in-hospital mortality were investigated using multivariable Cox proportional hazard regression models that included sex, age, marital status, ethnicity, somatic comorbidity, type of dementia and urgency of admission.

40,500 patients were included in the cohort. The overall in-hospital mortality rate was 11.1%. Factors that significantly increased the mortality risk were: male sex (adjusted hazard ratio (HR) 1.52, 95%-confidence interval (95%-CI) 1.43-1.63), higher age (adjusted HR 1.03, 95%-CI 1.03-1.04), living with a partner (adjusted HR 1.39, 95%-CI 1.30-1.49), acute admission (adjusted HR 2.16, 95%-CI 1.97-2.36) and Alzheimer's disease (adjusted HR 1.21, 95%-CI 1.13-1.29). Cardiovascular disease was the most common cause of in-hospital mortality.

This nationwide study found several independent risk factors for the in-hospital mortality of patients with dementia, including male sex, higher age, living with a partner, acute admission, and Alzheimer's disease. These risk factors should be taken into account by clinicians and caregivers as they will indicate whether patients are at risk of a more unfavourable outcome during hospital admission.