Improved Retention With 6-Month Clinic Return Intervals for Stable Human Immunodeficiency Virus-Infected Patients in Zambia.

Background: Extending appointment intervals for stable HIV-infected patients in sub-Saharan Africa can reduce patient opportunity costs and decongest overcrowded facilities. Methods: We analyzed a cohort of stable HIV-infected adults (on treatment with CD4 >200 cells/µL for more than 6 months) who presented for clinic visits in Lusaka, Zambia. We used multilevel, mixed-effects logistic regression adjusting for patient characteristics, including prior retention, to assess the association between scheduled appointment intervals and subsequent missed visits (>14 days late to next visit), gaps in medication (>14 days late to next pharmacy refill), and loss to follow-up (LTFU; >90 days late to next visit). Results: A total of 62084 patients (66.6% female, median age 38, median CD4 438 cells/µL) made 501281 visits while stable on antiretroviral therapy. Most visits were scheduled around 1-month (25.0% clinical, 44.4% pharmacy) or 3-month intervals (49.8% clinical, 35.2% pharmacy), with fewer patients scheduled at 6-month intervals (10.3% clinical, 0.4% pharmacy). After adjustment and compared to patients scheduled to return in 1 month, patients with six-month clinic return intervals were the least likely to miss visits (adjusted odds ratio [aOR], 0.20; 95% confidence interval [CI], 0.17-0.24); miss medication pickups (aOR, 0.47; 95% CI 0.39-0.57), and become LTFU prior to the next visit (aOR, 0.41; 95% CI, 0.31-0.54). Conclusions: Six-month clinic return intervals were associated with decreased lateness, gaps in medication, and LTFU in stable HIV-infected patients and may represent a promising strategy to reduce patient burdens and decongest clinics.

Application of a Multistate Model to Evaluate Visit Burden and Patient Stability to Improve Sustainability of Human Immunodeficiency Virus Treatment in Zambia.

Background: Differentiated service delivery (DSD) for human immunodeficiency virus (HIV)-infected persons who are clinically stable on antiretroviral therapy (ART) has been embraced as a solution to decrease access barriers and improve quality of care. However, successful DSD implementation is dependent on understanding the prevalence, incidence, and durability of clinical stability. Methods: We evaluated visit data in a cohort of HIV-infected adults who made at least 1 visit between 1 March 2013 and 28 February 2015 at 56 clinics in Zambia. We described visit frequency and appointment intervals using conventional stability criteria and used a mixed-effects linear regression model to identify predictors of appointment interval. We developed a multistate model to characterize patient stability over time and calculated incidence rates for transition between states. Results: Overall, 167819 patients made 3418018 post-ART initiation visits between 2004 and 2015. Fifty-four percent of visits were pharmacy refill-only visits, and 24% occurred among patients on ART for >6 months and whose current CD4 was >500 cells/mm3. Median appointment interval at clinician visits was 59 days, and time on ART and current CD4 were not strong predictors of appointment interval. Cumulative incidence of clinical stability was 66.2% at 2 years after enrollment, but transition to instability (31 events per 100 person-years) and lapses in care (41 events per100 person-years) were common. Conclusions: Current facility-based care was characterized by high visit burden due to pharmacy refills and among treatment-experienced patients. Differentiated service delivery models targeted toward stable patients need to be adaptive given that clinical stability was highly transient and lapses in care were common.