Examining Clinic-Based and Public Health Approaches to Ascertainment of HIV Care Status

Abstract

Introduction Clinic-based tracing efforts and public health surveillance data can provide different information about HIV care status for the same patients. The relative yield and how best to use these sources to identify and re-engage out of care patients is unknown. Methods At a large public HIV clinic in San Francisco, we selected a 10% random sample of active patients who were at least 210 days “late” for an HIV primary care visit as of April 1, 2013, for clinic-based outreach. Patients were considered out of care if they did not have an HIV primary care visit in the 210 days prior to April 1, 2013. We then matched the sample with the San Francisco Department of Public Health HIV surveillance registry. Patients with a CD4 or viral load result in the 210-day period were classified as in care. We compared results from both sources and estimated the cumulative incidence of disengagement from care for the full cohort of clinic patients. Results Of 940 patients lost to follow-up, 95 were sampled. Clinic tracing found 60 (63%) in care, 23 (24%) not located, 9 (10%) out of care, 2 (2%) incarcerated, and 1 (1%) had died. Of 42 individuals surveillance classified as out of care, tracing found 22 (52%) were in care. Of 52 patients found to be in care by surveillance, 12 (23%) were out of care by clinic tracing or unable to be located. The naïve estimate of the cumulative incidence of disengagement from care at three years for the active clinic cohort was 41.1% (95% Confidence Interval [CI]: 37.6%–44.5%). The use of surveillance data reduced this estimate to 12.7% (95% CI: 18.2%–25.4%) and when further corrected using tracing outcomes, the estimate dropped to only 6.4% (95%CI: 3.4%–9.4%). Conclusions Clinic-based tracing and surveillance data together provide a better understanding of care status than either method alone. Using surveillance data to inform clinic-based outreach efforts may be an effective strategy, though tracing efforts are most likely to be successful if conducted in real time.

Potential Impact of Integrating HIV Surveillance and Clinic Data on Retention-in-Care Estimates and Re-Engagement Efforts

“…Integration of surveillance data with clinical records reduced the number of patients who appeared to be out of care by half, which is similar to estimates from other settings. [18][19][20][21] Data integration also improved retention-in-care metrics and averted a substantial number of unnecessary case investigations by updating a patient's status before an investigation was initiated. Prevention of unnecessary case investigations would reduce waste and allow limited resources for patient re-engagement to be better targeted to those who truly need them.…”

“…Previous studies in specific clinics in Los Angeles, San Francisco, Seattle, and Chicago found that 45-52% of patients classified as ''out of care'' according to clinic medical records, in fact, had records of death, relocation, or evidence of care at another facility in state HIV surveillance databases. [18][19][20][21] These findings highlight the importance of collaboration between healthcare providers and state health departments in patient re-engagement efforts. However, it is unclear whether these estimates hold for other geographic settings and to what extent ongoing integration of HIV surveillance data in a clinic's re-engagement activities would impact the amount of resources needed to manage case loads.…”

Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults

“…131 Coordination with public health surveillance data systems is important, when possible, to improve linkage to, retention in, and reengagement in care. 7,132 …”

Addressing the Challenges of the HIV Continuum of Care in High-Prevalence Cities in the United States

“…Thus, clinic-based tracking and surveillance registry matching substantially reduced an estimate of the cumulative incidence of those lost to care over three years based on patient visit information alone. 44 …”