Over 50% of U.S. Group Have Gaps in HIV Care, but Half of Them Continue ART

Slightly more than half of U.S. adults with HIV had occasional 180-day gaps in their HIV primary care in a 4,275-person analysis of the HIV Research Network (HIVRN). But just more than half of people with occasional care gaps filled a prescription for antiretroviral therapy (ART) during a gap. The findings have implications not only for HIV care, but also for how researchers measure retention in care.

Retention in HIV care, often defined as clinic visits at least twice a year separated by 90 days, facilitates ART prescribing and monitoring and thus can be essential to HIV control. Research links worse retention to inconsistent viral control, lower CD4 counts and mortality. Authors of the new study observe that some HIV clinicians feel comfortable seeing stable patients once yearly and checking HIV RNA and other values twice yearly. The standard retention definition would classify such patients as not retained in care, even though these patients may continue ART and maintain viral suppression during apparent gaps in care. The new retention analysis aimed to determine whether people filled an ART prescription during gaps in care and to identify factors that predict prescriptions during gaps.

The analysis involved adults in care for HIV at five HIVRN sites in Massachusetts, Maryland and New York during an observation period from January 2006 through December 2010. The investigators determined which of these patients used Medicaid, an indicator of low income. They defined a gap in care as 180 or more days without a visit to an HIVRN outpatient HIV clinic, and they classified patients as never in a gap, always in a gap or occasionally in a gap.

The researchers used Medicaid pharmacy claims to determine whether a participant had a new ART prescription during a gap. A new prescription could involve either previously prescribed antiretrovirals or a new regimen. The HIVRN team assumed that new ART prescriptions during a gap usually indicated personal or phone contact with a medical provider, whereas prescription refills during a gap did not indicate contact with a provider.

The HIVRN team focused on 4,275 adult HIVRN participants matched to Medicaid files. Two-thirds (67.3%) were men, 58.5% black, 22.4% Hispanic, 17.8% white and 60.3% 40 years old or older. While 54.2% of participants were occasionally in a care gap, 6.6% were always in a gap. Among people with an occasional gap, 63.1% had one gap, 27.3% had two gaps and 9.6% had three or more gaps.

Logistic regression identified five factors that independently predicted a lower chance of occasionally being in a gap: first recorded viral load suppressed (relative risk ratio [RRR] 0.64), 51 to 64 years old (versus 18 to 30) (RRR 0.52), enrolled in HIVRN before 2006 (RRR 0.42), being a woman (RRR 0.74) and having sex between men as an HIV risk factor. Race did not predict occasional gaps in care.

Among 2,317 people with occasional gaps, 51% had a new ART prescription after 180 days in a gap. Unadjusted analysis identified four predictors of receiving a new ART prescription during a gap: two or three gaps (versus 1), longer total time in gaps, longer time on Medicaid and first recorded viral load suppressed. Logistic regression analysis focused on 3,389 gaps (instead of patients) pinpointed four independent predictors of a new ART prescription after 179 days in a gap: suppressed viral load closest to the gap start date (odds ratio 1.91), longer time in the gap (odds ratio 1.04 per month), higher proportion of months in gap enrolled in Medicaid and higher number of months in gap enrolled in Medicaid.

Next, the researchers considered 11,044 patient-provider pairs representing 2,264 patients and 2,405 providers. For about one-quarter of patient-provider pairs (27.1%), at least one new ART prescription was written after 179 days in a gap.

The authors conclude that new ART prescriptions during gaps in HIV primary are "fairly common" and predicted by viral load suppression close to the start of the gap. They believe these findings suggest growing provider comfort with prescribing ART in periods without a clinic visit. The researchers caution, though, that a new prescription during a gap may mean the patient saw a provider outside the HIVRN. Still, they argue that "[s]tandard retention measures do not account for people who have not attended HIV primary care visits but continue to fill ART prescriptions." They add that up to 60% of patients had gaps and did not receive ART, a finding that raises concerns about the health of the untreated person and risk of HIV transmission.