Browsing by Author "Glidden DV"

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Application of a Multistate Model to Evaluate Visit Burden and Patient Stability to Improve Sustainability of Human Immunodeficiency Virus Treatment in Zambia.
(2018-Sep-28) Roy M; Holmes C; Sikazwe I; Savory T; Mwanza MW; Bolton Moore C; Mulenga K; Czaicki N; Glidden DV; Padian N; Geng E; Division of Epidemiology, University of California Berkeley.; Division of HIV/AIDS, Infectious Diseases, and Global Medicine, University of California, San Francisco, San Francisco General Hospital.; Centre for Infectious Diseases Research in Zambia, Lusaka.; Department of Epidemiology and Biostatistics, University of California, San Francisco.; University of Alabama, Birmingham.; Johns Hopkins University School of Medicine, Baltimore, Maryland.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
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.
Differentiated Care Preferences of Stable Patients on Antiretroviral Therapy in Zambia: A Discrete Choice Experiment.
(2019-Aug-15) Eshun-Wilson I; Mukumbwa-Mwenechanya M; Kim HY; Zannolini A; Mwamba CP; Dowdy D; Kalunkumya E; Lumpa M; Beres LK; Roy M; Sharma A; Topp SM; Glidden DV; Padian N; Ehrenkranz P; Sikazwe I; Holmes CB; Bolton-Moore C; Geng EH; United Kingdom Department for International Development, Dar Es Salaam office, Tanzania.; University of California, San Francisco, San Francisco, CA.; University of California, Berkeley, Berkeley, CA.; Bill and Melinda Gates Foundation, Seattle, WA.; Georgetown University, Washington, DC.; Johns Hopkins University, Baltimore, MD.; James Cook University, Townsville, Australia.; Africa Health Research Institute, Durban, South Africa.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; University of Alabama at Birmingham, Birmingham, AL.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Although differentiated service delivery (DSD) models for stable patients on antiretroviral therapy (ART) offer a range of health systems innovations, their comparative desirability to patients remains unknown. We conducted a discrete choice experiment to quantify service attributes most desired by patients to inform model prioritization. METHODS: Between July and December 2016, a sample of HIV-positive adults on ART at 12 clinics in Zambia were asked to choose between 2 hypothetical facilities that differed across 6 DSD attributes. We used mixed logit models to explore preferences, heterogeneity, and trade-offs. RESULTS: Of 486 respondents, 59% were female and 85% resided in urban locations. Patients strongly preferred infrequent clinic visits [3- vs. 1-month visits: β (ie, relative utility) = 2.84; P < 0.001]. Milder preferences were observed for waiting time for ART pick-up (1 vs. 6 hours.; β = -0.67; P < 0.001) or provider (1 vs. 3 hours.; β = -0.41; P = 0.002); "buddy" ART collection (β = 0.84; P < 0.001); and ART pick-up location (clinic vs. community: β = 0.35; P = 0.028). Urban patients demonstrated a preference for collecting ART at a clinic (β = 1.32, P < 0.001), and although most rural patients preferred community ART pick-up (β = -0.74, P = 0.049), 40% of rural patients still preferred facility ART collection. CONCLUSIONS: Stable patients on ART primarily want to attend clinic infrequently, supporting a focus in Zambia on optimizing multimonth prescribing over other DSD features-particularly in urban areas. Substantial preference heterogeneity highlights the need for DSD models to be flexible, and accommodate both setting features and patient choice in their design.
Estimated mortality on HIV treatment among active patients and patients lost to follow-up in 4 provinces of Zambia: Findings from a multistage sampling-based survey.
(2018-Jan) Holmes CB; Sikazwe I; Sikombe K; Eshun-Wilson I; Czaicki N; Beres LK; Mukamba N; Simbeza S; Bolton Moore C; Hantuba C; Mwaba P; Phiri C; Padian N; Glidden DV; Geng E; University of California, San Francisco, San Francisco, California, United States of America.; Lusaka Apex Medical University, Lusaka, Zambia.; University of California, Berkeley, Berkeley, California, United States of America.; Stellenbosch University, Cape Town, South Africa.; Ministry of Health, Government of the Republic of Zambia, Lusaka, Zambia.; Georgetown University, Washington, DC, United States of America.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; University of Alabama at Birmingham, Birmingham, Alabama, United States of America.; Johns Hopkins University, Baltimore, Maryland, United States of America.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Survival represents the single most important indicator of successful HIV treatment. Routine monitoring fails to capture most deaths. As a result, both regional assessments of the impact of HIV services and identification of hotspots for improvement efforts are limited. We sought to assess true mortality on treatment, characterize the extent under-reporting of mortality in routine health information systems in Zambia, and identify drivers of mortality across sites and over time using a multistage, regionally representative sampling approach. METHODS AND FINDINGS: We enumerated all HIV infected adults on antiretroviral therapy (ART) who visited any one of 64 facilities across 4 provinces in Zambia during the 24-month period from 1 August 2013 to 31 July 2015. We identified a probability sample of patients who were lost to follow-up through selecting facilities probability proportional to size and then a simple random sample of lost patients. Outcomes among patients lost to follow-up were incorporated into survival analysis and multivariate regression through probability weights. Of 165,464 individuals (64% female, median age 39 years (IQR 33-46), median CD4 201 cells/mm3 (IQR 111-312), the 2-year cumulative incidence of mortality increased from 1.9% (95% CI 1.7%-2.0%) to a corrected rate of 7.0% (95% CI 5.7%-8.4%) (all ART users) and from 2.1% (95% CI 1.8%-2.4%) to 8.3% (95% CI 6.1%-10.7%) (new ART users). Revised provincial mortality rates ranged from 3-9 times higher than naïve rates for new ART users and were lowest in Lusaka Province (4.6 per 100 person-years) and highest in Western Province (8.7 per 100 person-years) after correction. Corrected mortality rates varied markedly by clinic, with an IQR of 3.5 to 7.5 deaths per 100 person-years and a high of 13.4 deaths per 100 person-years among new ART users, even after adjustment for clinical (e.g., pretherapy CD4) and contextual (e.g., province and clinic size) factors. Mortality rates (all ART users) were highest year 1 after treatment at 4.6/100 person-years (95% CI 3.9-5.5), 2.9/100 person-years (95% CI 2.1-3.9) in year 2, and approximately 1.6% per year through 8 years on treatment. In multivariate analysis, patient-level factors including male sex and pretherapy CD4 levels and WHO stage were associated with higher mortality among new ART users, while male sex and HIV disclosure were associated with mortality among all ART users. In both cases, being late (>14 days late for appointment) or lost (>90 days late for an appointment) was associated with deaths. We were unable to ascertain the vital status of about one-quarter of those lost and selected for tracing and did not adjudicate causes of death. CONCLUSIONS: HIV treatment in Zambia is not optimally effective. The high and sustained mortality rates and marked under-reporting of mortality at the provincial-level and unexplained heterogeneity between regions and sites suggest opportunities for the use of corrected mortality rates for quality improvement. A regionally representative sampling-based approach can bring gaps and opportunities for programs into clear epidemiological focus for local and global decision makers.
Longitudinal Care Cascade Outcomes Among People Eligible for Antiretroviral Therapy Who Are Newly Linking to Care in Zambia: A Multistate Analysis.
(2020-Dec-17) Mody A; Glidden DV; Eshun-Wilson I; Sikombe K; Simbeza S; Mukamba N; Somwe P; Beres LK; Pry J; Bolton-Moore C; Padian N; Holmes CB; Sikazwe I; Geng EH; Centre for Infectious Diseases Research in Zambia, Lusaka, Zambia.; Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA.; Division of Epidemiology, University of California, Berkeley, Berkeley, California, USA.; Division of Infectious Diseases, University of Alabama, Birmingham, Alabama, USA.; Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California, USA.; Department of International Health, Johns Hopkins University School of Public Health, Baltimore, Maryland, USA.; Department of Medicine, Georgetown University, Washington, D.C., USA.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Retention in human immunodeficiency virus (HIV) care is dynamic, with patients frequently transitioning in and out of care. Analytical approaches (eg, survival analyses) commonly used to assess HIV care cascade outcomes fail to capture such transitions and therefore incompletely represent care outcomes over time. METHODS: We analyzed antiretroviral therapy (ART)-eligible adults newly linking to care at 64 clinics in Zambia between 1 April 2014 and 31 July 2015. We used electronic medical record data and supplemented these with updated care outcomes ascertained by tracing a multistage random sample of patients lost to follow-up (LTFU, >90 days late for last appointment). We performed multistate analyses, incorporating weights from sampling, to estimate the prevalence of 9 care states over time since linkage with respect to ART initiation, retention in care, transfers, and mortality. RESULTS: In sum, 23 227 patients (58% female; median age 34 years [interquartile range 28-41]) were ART-eligible at enrollment. At 1 year, 75.2% had initiated ART and were in care: 61.8% were continuously retained, 6.1% had reengaged after LTFU, and 7.3% had transferred. Also, 10.1% were LTFU within 7 days of enrollment, and 15.2% were LTFU at 1 year (6.7% prior to ART). One year after LTFU, 51.6% of those LTFU prior to ART remained out of care compared to 30.2% of those LTFU after initiating ART. Overall, 6.9% of patients had died by 1 year with 3.0% dying prior to ART. CONCLUSION: Multistate analyses provide more complete assessments of longitudinal HIV cascade outcomes and reveal treatment gaps at distinct timepoints in care that will still need to be addressed even with universal treatment.
Mortality estimates by age and sex among persons living with HIV after ART initiation in Zambia using electronic medical records supplemented with tracing a sample of lost patients: A cohort study.
(2020-May) Kerkhoff AD; Sikombe K; Eshun-Wilson I; Sikazwe I; Glidden DV; Pry JM; Somwe P; Beres LK; Simbeza S; Mwamba C; Bukankala C; Hantuba C; Moore CB; Holmes CB; Padian N; Geng EH; Georgetown University, Washington, District of Columbia, United States of America.; Division of HIV, Infectious Diseases and Global Medicine, Zuckerberg San Francisco General Hospital and Trauma Center, University of California, San Francisco, San Francisco, California, United States of America.; University of California, Berkeley, Berkeley, California, United States of America.; Division of Infectious Diseases, Department of Medicine, Washington University, St. Louis, Missouri, United States of America.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; University of Alabama at Birmingham, Birmingham, Alabama, United States of America.; Johns Hopkins University, Baltimore, Maryland, United States of America.; Center for Dissemination and Implementation, Institute for Public Health, Washington University, St. Louis, Missouri, United States of America.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Men in sub-Saharan Africa have lower engagement and retention in HIV services compared to women, which may result in differential survival. However, the true magnitude of difference in HIV-related mortality between men and women receiving antiretroviral therapy (ART) is incompletely characterized. METHODS AND FINDINGS: We evaluated HIV-positive adults ≥18 years old newly initiating ART in 4 Zambian provinces (Eastern, Lusaka, Southern, and Western). In addition to mortality data obtained from routine electronic medical records, we intensively traced a random sample of patients lost to follow-up (LTFU) and incorporated tracing outcomes through inverse probability weights. Sex-specific mortality rates and rate differences were determined using Poisson regression. Parametric g-computation was used to estimate adjusted mortality rates by sex and age. The study included 49,129 adults newly initiated on ART between August 2013 and July 2015; overall, the median age among patients was 35 years, the median baseline CD4 count was 262 cells/μl, and 37.2% were men. Men comprised a smaller proportion of individuals starting ART (37.2% versus 62.8%), tended to be older (median age 37 versus 33 years), and tended to have lower CD4 counts (median 220 versus 289 cells/μl) at the time of ART initiation compared to women. The overall rate of mortality among men was 10.3 (95% CI 8.2-12.4) deaths/100 person-years (PYs), compared to 5.5 (95% CI 4.3-6.8) deaths/100 PYs among women (difference +4.7 [95% CI 2.3-7.2] deaths/100 PYs; p < 0.001). Compared to women in the same age groups, men's mortality rates were particularly elevated among those <30 years old (+6.7 deaths/100 PYs difference), those attending rural health centers (+9.4 deaths/100 PYs difference), those who had an initial CD4 count < 100 cells/μl (+9.2 deaths/100 PYs difference), and those who were unmarried (+8.0 deaths/100 PYs difference). After adjustment for potential confounders and mediators including CD4 count, a substantially higher mortality rate was predicted among men <30 years old compared to women of the same age, while women ≥50 years old had a mortality rate similar to that of age-matched men, but considerably higher than that predicted among young women (<30 years old). No clinically significant differences were evident with respect to rates of facility transfer or care disengagement between men and women. The main study limitations were the inability to successfully ascertain outcomes in all patients selected for tracing and missing clinical and laboratory data due to the use of medical records. CONCLUSIONS: In this study, we found that among HIV-positive adults newly initiating ART, mortality among men exceeded mortality among women; disparities were most pronounced among young patients. Older women, however, also experienced high mortality. Specific interventions for men and older women at highest mortality risk are needed to improve HIV treatment outcomes.
Novel Longitudinal Methods for Assessing Retention in Care: a Synthetic Review.
(2021-Aug) Mody A; Tram KH; Glidden DV; Eshun-Wilson I; Sikombe K; Mehrotra M; Pry JM; Geng EH; Centre for Infectious Diseases Research in Zambia, Lusaka, Zambia.; Division of Infectious Diseases, Washington University School of Medicine, Campus Box 8051, 4523 Clayton Avenue, St. Louis, Missouri, 63110, USA. aaloke.mody@wustl.edu.; Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA.; Division of Infectious Diseases, Washington University School of Medicine, Campus Box 8051, 4523 Clayton Avenue, St. Louis, Missouri, 63110, USA.; Department of Public Health Environments and Society, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
PURPOSE OF REVIEW: Retention in care is both dynamic and longitudinal in nature, but current approaches to retention often reduce these complex histories into cross-sectional metrics that obscure the nuanced experiences of patients receiving HIV care. In this review, we discuss contemporary approaches to assessing retention in care that captures its dynamic nature and the methodological and data considerations to do so. RECENT FINDINGS: Enhancing retention measurements either through patient tracing or "big data" approaches (including probabilistic matching) to link databases from different sources can be used to assess longitudinal retention from the perspective of the patient when they transition in and out of care and access care at different facilities. Novel longitudinal analytic approaches such as multi-state and group-based trajectory analyses are designed specifically for assessing metrics that can change over time such as retention in care. Multi-state analyses capture the transitions individuals make in between different retention states over time and provide a comprehensive depiction of longitudinal population-level outcomes. Group-based trajectory analyses can identify patient subgroups that follow distinctive retention trajectories over time and highlight the heterogeneity of retention patterns across the population. Emerging approaches to longitudinally measure retention in care provide nuanced assessments that reveal unique insights into different care gaps at different time points over an individuals' treatment. These methods help meet the needs of the current scientific agenda for retention and reveal important opportunities for developing more tailored interventions that target the varied care challenges patients may face over the course of lifelong treatment.
Participation in adherence clubs and on-time drug pickup among HIV-infected adults in Zambia: A matched-pair cluster randomized trial.
(2020-Jul) Roy M; Bolton-Moore C; Sikazwe I; Mukumbwa-Mwenechanya M; Efronson E; Mwamba C; Somwe P; Kalunkumya E; Lumpa M; Sharma A; Pry J; Mutale W; Ehrenkranz P; Glidden DV; Padian N; Topp S; Geng E; Holmes CB; University of California, Davis, Davis, California, United States of America.; University of California, Berkeley, Berkeley, California, United States of America.; University of Alabama, Tuscaloosa, Alabama, United States of America.; Bill and Melinda Gates Foundation, Seattle, Washington, United States of America.; James Cook University, Townsville, Queensland, Australia.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; University of California, San Francisco, San Fancisco, California, United States of America.; Johns Hopkins University, Baltimore, Maryland, United States of America.; Center for Global Health Practice and Impact, Georgetown University School of Medicine, Washington, District of Columbia, United States of America.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Current models of HIV service delivery, with frequent facility visits, have led to facility congestion, patient and healthcare provider dissatisfaction, and suboptimal quality of services and retention in care. The Zambian urban adherence club (AC) is a health service innovation designed to improve on-time drug pickup and retention in HIV care through off-hours facility access and pharmacist-led group drug distribution. Similar models of differentiated service delivery (DSD) have shown promise in South Africa, but observational analyses of these models are prone to bias and confounding. We sought to evaluate the effectiveness and implementation of ACs in Zambia using a more rigorous study design. METHODS AND FINDINGS: Using a matched-pair cluster randomized study design (ClinicalTrials.gov: NCT02776254), 10 clinics were randomized to intervention (5 clinics) or control (5 clinics). At each clinic, between May 19 and October 27, 2016, a systematic random sample was assessed for eligibility (HIV+, age ≥ 14 years, on ART >6 months, not acutely ill, CD4 count not <200 cells/mm3) and willingness to participate in an AC. Clinical and antiretroviral drug pickup data were obtained through the existing electronic medical record. AC meeting attendance data were collected at intervention facilities prospectively through October 28, 2017. The primary outcome was time to first late drug pickup (>7 days late). Intervention effect was estimated using unadjusted Kaplan-Meier survival curves and a Cox proportional hazards model to derive an adjusted hazard ratio (aHR). Medication possession ratio (MPR) and implementation outcomes (adoption, acceptability, appropriateness, feasibility, and fidelity) were additionally evaluated as secondary outcomes. Baseline characteristics were similar between 571 intervention and 489 control participants with respect to median age (42 versus 41 years), sex (62% versus 66% female), median time since ART initiation (4.8 versus 5.0 years), median CD4 count at study enrollment (506 versus 533 cells/mm3), and baseline retention (53% versus 55% with at least 1 late drug pickup in previous 12 months). The rate of late drug pickup was lower in intervention participants compared to control participants (aHR 0.26, 95% CI 0.15-0.45, p < 0.001). Median MPR was 100% in intervention participants compared to 96% in control participants (p < 0.001). Although 18% (683/3,734) of AC group meeting visits were missed, on-time drug pickup (within 7 days) still occurred in 51% (350/683) of these missed visits through alternate means (use of buddy pickup or early return to the facility). Qualitative evaluation suggests that the intervention was acceptable to both patients and providers. While patients embraced the convenience and patient-centeredness of the model, preference for traditional adherence counseling and need for greater human resources influenced intervention appropriateness and feasibility from the provider perspective. The main limitations of this study were the small number of clusters, lack of viral load data, and relatively short follow-up period. CONCLUSIONS: ACs were found to be an effective model of service delivery for reducing late ART drug pickup among HIV-infected adults in Zambia. Drug pickup outside of group meetings was relatively common and underscores the need for DSD models to be flexible and patient-centered if they are to be effective. TRIAL REGISTRATION: ClinicalTrials.gov NCT02776254.
Patient-reported Reasons for Stopping Care or Switching Clinics in Zambia: A Multisite, Regionally Representative Estimate Using a Multistage Sampling-based Approach in Zambia.
(2021-Oct-05) Sikazwe I; Eshun-Wilson I; Sikombe K; Beres LK; Somwe P; Mody A; Simbeza S; Bukankala C; Glidden DV; Mulenga LB; Padian N; Ehrenkranz P; Bolton-Moore C; Holmes CB; Geng EH; Washington University in St Louis, St Louis, Missouri, USA.; University of California Berkeley, Berkeley, California, USA.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; London School of Hygiene and Tropical Medicine, London, United Kingdom.; University of Alabama at Birmingham, Birmingham, Alabama, USA.; Ministry of Health, Lusaka, Zambia.; Bill and Melinda Gates Foundation, Seattle, Washington, USA.; Johns Hopkins University, Baltimore, Maryland, USA.; Georgetown University, Washington, D.C., USA.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Understanding patient-reported reasons for lapses of retention in human immunodeficiency virus (HIV) treatment can drive improvements in the care cascade. A systematic assessment of outcomes among a random sample of patients lost to follow-up (LTFU) from 32 clinics in Zambia to understand the reasons for silent transfers and disengagement from care was undertaken. METHODS: We traced a simple random sample of LTFU patients (>90 days from last scheduled visit) as determined from clinic-based electronic medical records from a probability sample of facilities. Among patients found in person, we solicited reasons for either stopping or switching care and predictors for re-engagement. We coded reasons into structural, psychosocial, and clinic-based barriers. RESULTS: Among 1751 LTFU patients traced and found alive, 31% of patients starting antiretroviral therapy (ART) between 1 July 2013 and 31 July 2015 silently transferred or were disengaged (40% male; median age, 35 years; median CD4 level, 239 cells/μL); median time on ART at LTFU was 480 days (interquartile range, 110-1295). Among the 544 patients not in care, median prevalences for patient-reported structural, psychosocial, and clinic-level barriers were 27.3%, 13.9%, and 13.4%, respectively, and were highly variable across facilities. Structural reasons, including, "relocated to a new place" were mostly cited among 289 patients who silently transferred (35.5%). We found that men were less likely to re-engage in care than women (odds ratio, .39; 95% confidence interval, .22-.67; P = .001). CONCLUSIONS: Efforts to improve retention of patients on ART may need to be tailored at the facility level to address patient-reported barriers.
Retention and viral suppression in a cohort of HIV patients on antiretroviral therapy in Zambia: Regionally representative estimates using a multistage-sampling-based approach.
(2019-May) Sikazwe I; Eshun-Wilson I; Sikombe K; Czaicki N; Somwe P; Mody A; Simbeza S; Glidden DV; Chizema E; Mulenga LB; Padian N; Duncombe CJ; Bolton-Moore C; Beres LK; Holmes CB; Geng E; University of California, San Francisco, San Francisco, California, United States of America.; Georgetown University, Washington, District of Columbia, United States of America.; International Association of Providers of AIDS Care, Washington, District of Columbia, United States of America.; University of California, Berkeley, Berkeley, California, United States of America.; Ministry of Health, Lusaka, Zambia.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; University of Alabama at Birmingham, Birmingham, Alabama, United States of America.; Johns Hopkins University, Baltimore, Maryland, United States of America.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Although the success of HIV treatment programs depends on retention and viral suppression, routine program monitoring of these outcomes may be incomplete. We used data from the national electronic medical record (EMR) system in Zambia to enumerate a large and regionally representative cohort of patients on treatment. We traced a random sample with unknown outcomes (lost to follow-up) to document true care status and HIV RNA levels. METHODS AND FINDINGS: On 31 July 2015, we selected facilities from 4 provinces in 12 joint strata defined by facility type and province with probability proportional to size. In each facility, we enumerated adults with at least 1 clinical encounter after treatment initiation in the previous 24 months. From this cohort, we identified lost-to-follow-up patients (defined as 90 or more days late for their last appointment), selected a random sample, and intensively reviewed their records and traced them via phone calls and in-person visits in the community. In 1 of 4 provinces, we also collected dried blood spots (DBSs) for plasma HIV RNA testing. We used inverse probability weights to incorporate sampling outcomes into Aalen-Johansen and Cox proportional hazards regression to estimate retention and viremia. We used a bias analysis approach to correct for the known inaccuracy of plasma HIV RNA levels obtained from DBSs. From a total of 64 facilities with 165,464 adults on ART, we selected 32 facilities with 104,966 patients, of whom 17,602 (17%) were lost to follow-up: Those lost to follow-up had median age 36 years, 60% were female (N = 11,241), they had median enrollment CD4 count of 220 cells/μl, and 38% had WHO stage 1 clinical disease (N = 10,690). We traced 2,892 (16%) and found updated outcomes for 2,163 (75%): 412 (19%) had died, 836 (39%) were alive and in care at their original clinic, 457 (21%) had transferred to a new clinic, 255 (12%) were alive and out of care, and 203 (9%) were alive but we were unable to determine care status. Estimates using data from the EMR only suggested that 42.7% (95% CI 38.0%-47.1%) of new ART starters and 72.3% (95% CI 71.8%-73.0%) of all ART users were retained at 2 years. After incorporating updated data through tracing, we found that 77.3% (95% CI 70.5%-84.0%) of new initiates and 91.2% (95% CI 90.5%-91.8%) of all ART users were retained (at original clinic or transferred), indicating that routine program data underestimated retention in care markedly. In Lusaka Province, HIV RNA levels greater than or equal to 1,000 copies/ml were present in 18.1% (95% CI 14.0%-22.3%) of patients in care, 71.3% (95% CI 58.2%-84.4%) of lost patients, and 24.7% (95% CI 21.0%-29.3%). The main study limitations were imperfect response rates and the use of self-reported care status. CONCLUSIONS: In this region of Zambia, routine program data underestimated retention, and the point prevalence of unsuppressed HIV RNA was high when lost patients were accounted for. Viremia was prevalent among patients who unofficially transferred: Sustained engagement remains a challenge among HIV patients in Zambia, and targeted sampling is an effective strategy to identify such gaps in the care cascade and monitor programmatic progress.