Estimating the Cost of Increasing Retention in Care for HIV-Infected Patients: Results of the CDC/HRSA Retention in Care Trial

Background:  An estimated 1.2 million people are living with HIV in the United States, and approximately 942,000 of them have been diagnosed and are aware of their infection. Retaining HIV-infected persons in medical care is important for access to antiretroviral therapy, viral load suppression, and preventing HIV transmission to sex and needle sharing partners.  Objective:  To provide the first estimates of the programmatic costs of an intervention to retain HIV patients in care based on primary data from a multisite randomized controlled trial in the United States.  Methods:  Each of six academically affiliated HIV clinics randomized patients to intervention and control arms. The clinics were located in Boston, MA, Brooklyn, NY, Baltimore, MD, Birmingham, AL, Miami, FL, and Houston, TX.  The intervention arm (N=615 patients) used trained interventionists over 12 months, who delivered enhanced personal contacts (e.g., reminder calls, interim visit calls, missed visit calls, brief face-to-face meetings) and basic HIV education to improve retention in care. The comparison arm (N=613 patients) as well as the intervention arm continued to receive standard of care (SOC) practices (e.g., appointment reminders through the mail or automatic phone calls). Retention in care was defined as 4-month visit constancy: at least one kept primary care visit in each 4-month interval over 12 months. The cost per additional patient retained in care beyond that expected in standard of care was calculated by dividing the additional costs of the intervention arm by the number of patients retained in care beyond that observed in the SOC arm. We used micro-costing methods to collect unit cost and quantity of resources used to implement the retention in care intervention in each HIV care clinic. We collected all fixed and variable costs of the intervention and aggregated them over a 12-month period. We included labor and non-labor costs attributable to staff time, training, travel, supplies, equipment, facility space, and utilities.  Results:  Four-month visit constancy was achieved by 280 (45.7%) patients in the SOC arm and by 343 (55.8%) patients in the intervention arm, an increase of 63 patients (relative improvement 22.1%; 95% CI 9%-36%, P < 0.01). We estimated the total cost of the intervention at the six clinics to be $241,565; the median cost per site was $43,523 per year (range $20,917-$53,587). Dividing the total cost by the 63 patients retained in care beyond expected under SOC, we found the cost per additional patient retained in care to be $3,834. Approximately 84% of the total intervention costs were labor costs.  Conclusion:  Our analysis shows that a successful retention in care intervention consisting of enhanced personal contacts coupled with basic HIV education may be delivered at a fairly low cost. Interventions that improve retention in care can benefit patients’ health and lower HIV transmission risk. The results provide useful information for scaling up retention in HIV care interventions and efficient allocation of HIV prevention resources.