Comparing different measures of retention in outpatient HIV care

The US National HIV/AIDS Strategy identifies retention in care as an important quality performance measure. There is no gold standard to measure retention in care. This study is the first to compare different measures of retention, using a large geographically diverse sample.

A prospective cohort of 17,425 HIV-infected adults enrolled in care at 12 US HIV clinics between 2001 and 2008.

We compared three measures of retention for each patient: proportion of time not spent in a gap of more than 6 months between successive outpatient visits; proportion of 91-day quarters in which at least one visit occurred; proportion of years in which two or more visits separated by at least 90 days occurred. Associations among measures and effects of sociodemographic and clinical characteristics were examined.

The three measures of retention were moderately to strongly correlated. Averaging across patients, 71% of time in care was not spent in a gap more than 6 months; 73% of all quarters had at least one visit; and 75% of all years had at least two visits separated by at least 90 days. For all measures, retention was significantly higher for women, whites, older individuals, men who had sex with men (MSM)-related HIV transmission, and initial CD4 cell counts 50 cell/microl or less.

This is one of the first studies to provide a national estimate of retention in HIV care in the US, which ranged from 71 to 75% using any of the accepted retention measures. Future studies should assess how well different measures predict clinical outcomes and establish acceptable target levels for retention.