Geographic Variations in Retention in Care among HIV-Infected Adults in the United States

Abstract

Objective: To understand geographic variations in clinical retention, a central component of the HIV care continuum and key to improving individual- and population-level HIV outcomes.

Design: We evaluated retention by US region in a retrospective observational study.

Methods: Adults receiving care from 2000-2010 in 12 clinical cohorts of the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) contributed data. Individuals were assigned to Centers for Disease Control and Prevention (CDC)-defined regions by residential data (10 cohorts) and clinic location as proxy (2 cohorts). Retention was ≥2 primary HIV outpatient visits within a calendar year, >90 days apart. Trends and regional differences were analyzed using modified Poisson regression with clustering, adjusting for time in care, age, sex, race/ethnicity, and HIV risk, and stratified by baseline CD4+ count.

Results: Among 78,993 adults with 444,212 person-years of follow-up, median time in care was 7 years (Interquartile Range: 4-9). Retention increased from 2000 to 2010: from 73% (5,000/6,875) to 85% (7,189/8,462) in the Northeast, 75% (1,778/2,356) to 87% (1,630/1,880) in the Midwest, 68% (8,451/12,417) to 80% (9,892/12,304) in the South, and 68% (5,147/7,520) to 72% (6,401/8,895) in the West. In adjusted analyses, retention improved over time in all regions (p<0.01, trend), although the average percent retained lagged in the West and South vs. the Northeast (p<0.01).

Conclusions: In our population, retention improved, though regional differences persisted even after adjusting for demographic and HIV risk factors. These data demonstrate regional differences in the US which may affect patient care, despite national care recommendations.

Fig 1. Temporal trends in percentage of individuals successfully clinically retained in the NA-ACCORD by CDC-defined region of the United States, from 2000–2010, by CDC-defined region of the United States.

Diamonds are National HIV/AIDS Strategy/Institute of Medicine retention indicator percentages (≥2 visits in a calendar year, >90 days apart). Circles are Predictive Margins for the Probability of Being Retained by IOM indicator using a Region-by-Time interaction effect (Fully Adjusted Logistic Model with GEE) U.S. Centers for Disease Control and Prevention (CDC)-defined Regions: Northeast: CT, ME, MA, NH, NJ, NY, PA, RI, VT; Midwest: IL, IN, IA, KS, MI, MN, MO, NE, ND, OH, SD, WI; South: AL, AR, DE, DC, FL, GA, KY, LA, MD, MS, NC, OK, SC, TN, TX, VA, WV; West: AK, AZ, CA, CO, HI, ID, MT, NV, NM, OR, UT, WA, WY.

Fig 2. Risk Ratio estimates and 95% Confidence Intervals for factors associated with retention.

Results from modified Poisson regression model using a Generalized Estimating Equation and adjusting for total time in care.

Fig 3. Region-level map of observed clinical retention status within the study sample in 2009 (N = 47,247), the final year in which all 12 clinical cohorts contributed data.

Fig 4. State-level map of observed clinical retention status within the study sample in 2009 (N = 47,247), the final year in which all 12 clinical cohorts contributed data.

Fig 5. ZCTA-level map of observed clinical retention status within the study sample in 2009 (N = 47,247), the final year in which all 12 clinical cohorts contributed data.