Dementia after delirium in patients with femoral neck fractures

OBJECTIVES: To investigate whether delirium in older patients with femoral neck fractures is associated with an increased risk of developing dementia and a higher mortality rate. Design: A 5-year prospective follow-up study. Setting: Department of Orthopedic Surgery at the University Hospital in Umea, Sweden. Participants: Seventy-eight nondemented patients aged 65 and older operated on for femoral neck fractures were followed for 5 years. Measurements: The patients were assessed using the Organic Brain Syndrome (OBS) Scale pre- and postoperatively. Medical and social data were collected from the patients, their caregivers, and medical records, and the survivors were visited and assessed with the OBS Scale and the Mini-Mental State Examination in their homes 5 years after the fracture. Results: Thirty of 78 (38.5%) nondemented patients with a femoral neck fracture developed dementia within a 5-year period. Twenty of 29 (69%) who were delirious postoperatively developed dementia, compared with 10 of 49 (20%) who were not delirious during their hospital stay (P < .001). Twenty-one (72.4%) of those with postoperative delirium died within 5 years, compared with 17 of 49 (34.7%) of those who remained lucid postoperatively (P = .004). Conclusion: Delirium in nondemented femoral neck fracture patients is associated with the development of dementia and a higher mortality rate. Patients with preoperative or postoperative delirium should therefore be assessed not only for the etiology of the delirium but also for any underlying organic brain disorder. Questions that remain unanswered are whether postoperative delirium is a marker of undetected dementia and whether postoperative delirium contributes to the development of dementia.