In this study of delirium in older hip fracture patients, the MDAS, a continuous severity measure, was a useful adjunct to the CAM, a dichotomous diagnostic measure. In patients with CAM-defined delirium, severe delirium was generally associated with worse outcomes than was mild delirium. In patients who did not fulfill CAM criteria, subsyndromal delirium was associated with worse outcomes than having few or no symptoms of delirium. Patients with subsyndromal delirium had outcomes similar to patients with mild delirium, suggesting that a dichotomous approach to diagnosis and management may be inappropriate. Pure hypoactive delirium was more common than delirium with any hyperactive features, tended to be milder, and was associated with better outcomes even after adjusting for severity. Future studies should confirm our preliminary associations and examine whether treatment to reduce the severity of delirium symptoms can improve outcomes after hip fracture repair.