Table 1.

Measures of retention in care calculated over a 12-month observation period among 10,053 HIV-infected patients receiving medical care at six academically-affiliated HIV clinics during the year preceding implementation of the CDC/HRSA Retention in Care intervention, 2008–09.

Retention Measure	Description
Missed visits (count)	Number of “no show” visits accrued (count measure, observed range=1–14)
Missed visits (dichotomous)	Measure of any “no show” visits (dichotomous measure, `no' = retained)
Visit adherence	Proportion of kept visits / scheduled visits (kept + “no-show” visits) (continuous measure, range=0.0–1.0)
4-month visit constancy	Number of 4-month intervals with at least 1 kept visit (categorical measure, range=0–3)
6-month gap	≥ 189 days elapsed between sequential kept visits (dichotomous measure, `no' = retained)
HRSA HAB measure	2 kept visits separated by ≥ 90 days (dichotomous measure, `yes' = retained)

In accordance with prior studies, only scheduled clinic visits with a primary HIV medical provider were included in calculating retention measures. “No-show” visits are defined as visits not canceled in advance of the scheduled appointment by the patient, provider or clinic.