Background: Measuring retention in HIV primary care is complex, as care includes multiple visits scheduled at varying intervals over time. We evaluated 6 commonly used retention measures in predicting viral load (VL) suppression and the correlation among measures.
Methods: Clinic-wide patient-level data from 6 academic HIV clinics were used for 12 months preceding implementation of the Centers for Disease Control and Prevention/Health Resources and Services Administration (CDC/HRSA) retention in care intervention. Six retention measures were calculated for each patient based on scheduled primary HIV provider visits: count and dichotomous missed visits, visit adherence, 6-month gap, 4-month visit constancy, and the HRSA HIV/AIDS Bureau (HRSA HAB) retention measure. Spearman correlation coefficients and separate unadjusted logistic regression models compared retention measures with one another and with 12-month VL suppression, respectively. The discriminatory capacity of each measure was assessed with the c-statistic.
Results: Among 10,053 patients, 8235 (82%) had 12-month VL measures, with 6304 (77%) achieving suppression (VL <400 copies/mL). All 6 retention measures were significantly associated (P < 0.0001) with VL suppression (odds ratio; 95% CI, c-statistic): missed visit count (0.73; 0.71 to 0.75, 0.67), missed visit dichotomous (3.2; 2.8 to 3.6, 0.62), visit adherence (3.9; 3.5 to 4.3,0.69), gap (3.0; 2.6 to 3.3, 0.61), visit constancy (2.8; 2.5 to 3.0, 0.63), and HRSA HAB (3.8; 3.3 to 4.4, 0.59). Measures incorporating “no-show” visits were highly correlated (Spearman coefficient = 0.83–0.85), as were measures based solely on kept visits (Spearman coefficient = 0.72–0.77). Correlation coefficients were lower across these 2 groups of measures (range = 0.16–0.57).
Conclusions: Six retention measures displayed a wide range of correlation with one another, yet each measure had significant association and modest discrimination for VL suppression. These data suggest there is no clear gold standard and that selection of a retention measure may be tailored to context.
*Division of Infectious Diseases, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
†Department of Medicine, Section of Health Services Research, Baylor College of Medicine, Houston, TX
‡Health Services Research and Development Center of Excellence at the Michael E. DeBakey VA Medical Center, Houston, TX
§Section of Infectious Diseases, Boston University Medical Center, Boston, MA
‖Department of Health Policy and Management, School of Public Health, Boston University Medical Center, Boston, MA
¶Center for Health Quality, Outcomes and Economic Research, Edith Nourse Rogers Memorial Veterans Hospital
#Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA
**Division of Infectious Diseases, Department of Medicine, Johns Hopkins University, Baltimore, MD
††Division of Science and Policy, Health Resources and Services Administration, HIV/AIDS Bureau, Rockville, MD
‡‡Division of Health Services Research and Policy, Department of Epidemiology, School of Public Health, University of Miami
§§Department of Community Health Sciences, School of Public Health, State University of New York, Downstate Medical Center, New York, NY
‖‖Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX.
Correspondence to: Michael J. Mugavero, MD, MHSc, 1530 3rd Avenue S, BBRB 206H, Birmingham, AL, USA 35294-2170 (e-mail: email@example.com).
Supported by the Centers for Disease Control and Prevention (CDC) and the Health Resources and Services Administration through CDC contracts 200-2007-23685, 200-2007-23690, 200-2007-23689, 200-2007-23687, 200-2007-23684, 200-2007-23692. M. J. Mugavero was also supported by National Institute of Mental Health Grant 5K23MH082641-05.
Presented in part at the 7th International Conference on HIV Treatment and Prevention Adherence, June 3–5, 2012, Miami, FL.
MJM has received consulting fees (advisory board) from Bristol-Myers Squibb, Gilead Sciences and Merck Foundation, and grant support from Bristol-Myers Squibb, Pfizer, Inc, Tibotec Therapeutics, and Definicare, LLC.
The other authors have no conflicts of interest to disclose.
Retention in Care (RIC) Study Group is included in the ACKNOWLEDGEMENTS section.
Received May 24, 2012
Accepted September 07, 2012