Risk factors for in-hospital mortality in patients with dementia

Abstract

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

Study design: 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.

Main outcome measures: 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.

Results: 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.

Conclusions: 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.

Keywords: Dementia; In-hospital mortality; Older adults; Prognosis; Risk factors.