House calls, also referred to as home visits, are increasing in the United States.¹ Approximately 40% of patient visits in the 1930s were house calls.^1,2 By 1996, this decreased to 0.5% because insurance reimbursements for house calls decreased.^1,2 The pendulum in the United States is swinging again to house calls because of the need to develop care models for the growing aging population.^1,3,4 The proportion of house calls to outpatient clinic visits conducted by family physicians in the United States is unlikely to reach the 1930s levels; however, the number of house calls conducted from 1996 to 2016 doubled.³ Medicare Part B billing and reimbursement for house calls are also increasing, with nearly 2.6 million house calls paid in 2015.⁵

The increasing popularity of and call for home-based care have led to an increased need to study the outcomes and design of home-based primary care models in the United States. The two largest home-based primary care studies are the Centers for Medicare and Medicaid Services Independence at Home Demonstration and the U.S. Department of Veterans Affairs home-based primary care program.^6,7 The Independence at Home program demonstrated a 23% reduction in hospitalizations, a 27% decrease in 30-day readmissions, and a cost savings of $111 per beneficiary per month, which is a $70 million savings over three years.^7–10 Similarly, a large systematic review (N = 46,154; nine studies) evaluating home-based primary care outcomes for homebound older adults reported fewer hospitalizations, hospital bed days of care, emergency department visits, long-term care admissions, and long-term bed days of care.¹¹ The U.S. Department of Veterans Affairs home-based primary care study of chronically ill, frail adults (N = 179) in urban populations also found fewer hospital admissions and bed days of care, but no change in emergency department use.¹²

House calls benefit patients post-hospitalization by reducing readmission rates, associated health care costs, and errors related to transitions of care.^13,14 There is an increased need for home-based care for the most vulnerable populations because of the recent shift in the United States toward value-based health care.^1,3 In 2011, there were 2 million homebound people in the United States, of which only 12% reported receiving home-based primary care.¹⁵ This number is expected to increase to 4 million by 2030.¹

House calls also benefit patients with socioeconomic barriers to care, including pregnant patients and children who are at high risk of abuse.¹⁶ Nurse- or social worker–led home visiting programs have reduced child maltreatment, decreased child health care overutilization, and improved cognitive skills of children born to a low income household with limited psychological resources.^16–18 Outcome data for physician-led house calls are limited for younger populations because most data are from studies on older adults. A meta-analysis of 51 studies of home-based family care reported small, statistically significant improvements in child cognitive outcomes, maternal life outcomes, and parental behaviors and skills.¹⁹ Additionally, a Cochrane review of 11,000 newly postpartum patients receiving frequent in-home visits from interdisciplinary teams showed a decrease in infant health service utilization and an increase in maternal interest in exclusive breastfeeding.²⁰