In-Hospital Delirium as a Prognostic Factor for New Cognitive Disorder in a 1-Year Post-Hip Fracture Follow-Up.

Background Older hip fracture patients are at high risk of delirium during acute hospital care. Pre-fracture dementia is known to increase the risk of in-hospital delirium. Data on the development of new cognitive disorders in patients with delirium are scarce. Objective The objective of this study is to evaluate the prognostic significance of in-hospital delirium on the development of new cognitive disorders in a 1-year follow-up in older hip fracture patients. Material and methods Data consisted of 476 hip fracture patients aged 65 years or more with no known cognitive disorder on admission. Delirium was assessed using the Confusion Assessment Method (CAM). Cognitive disorders were diagnosed following the national guidelines. Information on the new diagnoses of cognitive disorders (NDCD) at 1-year follow-up was elicited in a telephone interview and confirmed from the electronic patient files. Logistic regression analyses were conducted to examine the association of delirium with NDCDs. Results Of the 476 patients, 87 (18%) had delirium during hospital stay. Patients with delirium were older, they had poorer nutritional status, lower mobility level, and more supported living arrangements than did patients without delirium. At the 1-year time point, 205 (43%) had NDCDs or were strongly suspected of this. CAM result was statistically significantly associated with development of NDCD in multivariable-adjusted analysis (odds ratio [OR] 2.29; 95% confidence interval [CI]: 1.39-3.79). Also, poor nutritional status continued to be associated with NDCDs (multivariable-adjusted OR 1.58; 95% CI: 1.03-2.43). Conclusion Delirium during hospitalization and poor nutritional status on admission are independent prognostic factors for development of subsequent cognitive disorders in older hip fracture patients.