Background
High-cost, high-need users are defined as patients who accumulate large numbers of emergency department visits and hospital admissions that might have been prevented by relatively inexpensive early interventions and primary care. This phenomenon has not been previously described in HIV-infected individuals.

Methods
We analyzed the health records of HIV-infected individuals using scheduled or unscheduled inpatient or outpatient health care in St James's Hospital, Dublin, Ireland, from October 2014 to October 2015.

Results
Twenty-two of 2063 HIV-infected individuals had a cumulative length of stay >30 days in the study period. These individuals accrued 99 emergency department attendances and 1581 inpatient bed days, with a direct cost to the hospital of >€1 million during the study period. Eighteen of 22 had potentially preventable requirements for unscheduled care. Two of 18 had a late diagnosis of HIV. Sixteen of 18 had not been successfully engaged in outpatient HIV care and presented with consequences of advanced HIV. Fourteen of 16 of those who were not successfully engaged in care had ≥1 barrier to care (addiction, psychiatric disease, and/or homelessness).

Conclusions
A small number of HIV-infected individuals account for a high volume of acute unscheduled care. Intensive engagement in outpatient care may prevent some of this usage and ensuing costs.