As health systems seek to reduce spending and improve care quality in response to changing payment schemes, one key strategy is to substitute lower‐intensity care settings (e.g. outpatient care) for more expensive ones (e.g. hospitals and emergency departments) whenever possible. Caring for patients at home can allow for a quicker return to independence at lower costs. Some health systems have adopted a “hospital‐at‐home” program to deliver inpatient‐level care in the outpatient setting, but to our knowledge no one has created an intervention to deliver home observation‐level care.


Many patients admitted through the ED could otherwise be sent home if enhanced home‐based treatment and close monitoring (e.g. observation unit‐level care) were available. We sought to create such a program at the Massachusetts General Hospital (MGH) ED that could prevent low‐acuity inpatient admissions.


Upon referral to the Mobile Observation Unit (MOU) by ED clinicians, patients were evaluated by the MOU nurse practitioner who determined if the patient met eligibility requirements, including: having an in‐network PCP; stable medical status; a non‐psychiatric primary diagnosis; residence within the geographic catchment area; and no requirements for IV medications. If eligible, patients were discharged home and the same NP visited the patient at home as soon as 2 hours but no later than 24 hours after discharge to conduct an intensive, structured visit, including patient counseling, medication reconciliation, coordination with primary care providers, a home safety evaluation, and transition to traditional home care as required. If needed, the NP offered coverage by telephone until outpatient care could be arranged. There was no patient charge for the service.

The pilot program took place at the MGH ED from June 2013 to September 2013. During the pilot, 61 patients were referred to the MOU, of which 17 met inclusion criteria. Participants had a mean age of 75 years, and five were considered “high‐risk” patients enrolled in our hospital’s high‐risk case management program. 35% of patients (6 out of 17) would have otherwise been admitted, as determined by the ED team and the MOU NP, at a total cost of $41,808. 93% (15/16) patients received follow‐up PCP care within 2 weeks. Within 30 days after MOU discharge, four patients presented back to the ER, of which three were high‐risk patients and one was a planned return; two of these patients were admitted (12.5%).


The pilot provided important proof‐of‐concept that a home‐based intervention could safely provide observation‐level care and prevent hospital admissions among medically stable patients. A more detailed program evaluation is underway to calculate return‐on‐investment and additional patient outcomes. We are planning an expansion of the program to other in‐network hospitals, and are working to refine the clinical intervention and to better integrate the MOU into the ED workflow.