Association of depressive disorders and dementia with mortality among older people with hip fracture

Erika Olofsson, Yngve Gustafson, Sebastian Mukka, Eva Tengman, Lenita Lindgren, Birgitta Olofsson

Hip fracture (HF) is a significant cause of mortality among older people. Almost half of the patients with HF have dementia, which increases the mortality risk further. Cognitive impairment is associated with depressive disorders (DDs) and both dementia and DDs are independent risk factors for poor outcome after HF. However, most studies that evaluate mortality risk after HF separate these conditions. To investigate whether dementia with depressive disorders (DDwD) affects the mortality risk at 12, 24, and 36 months after HF among older people. Patients with acute HF (n = 404) were included in this retrospective analysis of two randomized controlled trials performed in orthopedic and geriatric departments. Depressive symptoms were assessed using the Geriatric Depression Scale and cognitive function was assessed using the Mini-Mental State Examination. A consultant geriatrician made final depressive disorder and dementia diagnoses using the Diagnostic and Statistical Manual of Mental Disorders criteria, with support from assessments and medical records. The 12-, 24- and 36-month mortality after HF was analyzed using logistic regression models adjusted for covariates. In analyses adjusted for age, sex, comorbidity, pre-fracture walking ability, and fracture type, patients with DDwD had increased mortality risks at 12 [odds ratio (OR) 4.67, 95% confidence interval (CI) 1.75-12.51], 24 (OR 3.61, 95% CI 1.71-7.60), and 36 (OR 4.53, 95% CI 2.24-9.14) months. Similar results were obtained for patients with dementia, but not depressive disorders, alone. DDwD is an important risk factor for increased mortality at 12, 24, and 36 months after HF among older people. Routinely assessments after HF for cognitive- and depressive disorders could identify patients at risk for increased mortality, and enable early interventions. RCT2: International Standard Randomized Controlled Trial Number Register, trial registration number: ISRCTN15738119.