Many elderly patients with uncomplicated treatment courses are admitted unnecessarily, which is a burden for the patient and society. Studies show that Hospital at Home (HaH) treatment is an alternative to hospitalization. The patient's risk of delirium, infection and loss of function is reduced when the patient avoids the hospital stay. HaH treatment is expected to be more cost-effective, improve patients' functional abilities and patients' satisfaction. Three municipalities, general practitioners, pre-hospital service and an emergency department (ED) in Central Denmark Region have organized the first HaH treatment model across disciplines and sectors. Specialists in the ED and the municipal acute teams provide HaH treatment for elderly acute ill patients. However, the model has not yet been evaluated. The aim of this study is to optimize the HaH treatment model for elderly acute ill patients. The objective is to increase patient satisfaction and optimize the use of resources in healthcare by avoiding unnecessary hospitalizations that impair and prolong treatment. This study is an open label randomized controlled trial (RCT) with a 1:2 allocation ratio of acute hospital admission versus HaH. During a pilot period, we tested and adapted the patient pathway of HaH to the practical reality, before we start the randomization for the RCT study. We will investigate the clinical effects and health economic consequences of HaH treatment compared with standard hospital treatment.