Browsing by Author "Dowdy D"

Now showing 1 - 3 of 3

Costs and cost-effectiveness of a comprehensive tuberculosis case finding strategy in Zambia.
(2021) Jo Y; Kagujje M; Johnson K; Dowdy D; Hangoma P; Chiliukutu L; Muyoyeta M; Sohn H
INTRODUCTION: Active-case finding (ACF) programs have an important role in addressing case detection gaps and halting tuberculosis (TB) transmission. Evidence is limited on the cost-effectiveness of ACF interventions, particularly on how their value is impacted by different operational, epidemiological and patient care-seeking patterns. METHODS: We evaluated the costs and cost-effectiveness of a combined facility and community-based ACF intervention in Zambia that utilized mobile chest X-ray with computer-aided reading/interpretation software and laboratory-based Xpert MTB/RIF testing. Programmatic costs (in 2018 US dollars) were assessed from the health system perspective using prospectively collected cost and operational data. Cost-effectiveness of the ACF intervention was assessed as the incremental cost per TB death averted over a five-year time horizon using a multi-stage Markov state-transition model reflecting patient symptom-associated care-seeking and TB care under ACF compared to passive care. RESULTS: Over 18 months of field operations, the ACF intervention costed $435 to diagnose and initiate treatment for one person with TB. After accounting for patient symptom-associated care-seeking patterns in Zambia, we estimate that this one-time ACF intervention would incrementally diagnose 407 (7,207 versus 6,800) TB patients and avert 502 (611 versus 1,113) TB-associated deaths compared to the status quo (passive case finding), at an incremental cost of $2,284 per death averted over the next five-year period. HIV/TB mortality rate, patient symptom-associated care-seeking probabilities in the absence of ACF, and the costs of ACF patient screening were key drivers of cost-effectiveness. CONCLUSIONS: A one-time comprehensive ACF intervention simultaneously operating in public health clinics and corresponding catchment communities can have important medium-term impact on case-finding and be cost-effective in Zambia. The value of such interventions increases if targeted to populations with high HIV/TB mortality, substantial barriers (both behavioral and physical) to care-seeking exist, and when ACF interventions can optimize screening by achieving operational efficiency.
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
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.
Sustainable HIV treatment in Africa through viral-load-informed differentiated care.
(2015-Dec-03) Phillips A; Shroufi A; Vojnov L; Cohn J; Roberts T; Ellman T; Bonner K; Rousseau C; Garnett G; Cambiano V; Nakagawa F; Ford D; Bansi-Matharu L; Miners A; Lundgren JD; Eaton JW; Parkes-Ratanshi R; Katz Z; Maman D; Ford N; Vitoria M; Doherty M; Dowdy D; Nichols B; Murtagh M; Wareham M; Palamountain KM; Chakanyuka Musanhu C; Stevens W; Katzenstein D; Ciaranello A; Barnabas R; Braithwaite RS; Bendavid E; Nathoo KJ; van de Vijver D; Wilson DP; Holmes C; Bershteyn A; Walker S; Raizes E; Jani I; Nelson LJ; Peeling R; Terris-Prestholt F; Murungu J; Mutasa-Apollo T; Hallett TB; Revill P
There are inefficiencies in current approaches to monitoring patients on antiretroviral therapy in sub-Saharan Africa. Patients typically attend clinics every 1 to 3 months for clinical assessment. The clinic costs are comparable with the costs of the drugs themselves and CD4 counts are measured every 6 months, but patients are rarely switched to second-line therapies. To ensure sustainability of treatment programmes, a transition to more cost-effective delivery of antiretroviral therapy is needed. In contrast to the CD4 count, measurement of the level of HIV RNA in plasma (the viral load) provides a direct measure of the current treatment effect. Viral-load-informed differentiated care is a means of tailoring care so that those with suppressed viral load visit the clinic less frequently and attention is focussed on those with unsuppressed viral load to promote adherence and timely switching to a second-line regimen. The most feasible approach to measuring viral load in many countries is to collect dried blood spot samples for testing in regional laboratories; however, there have been concerns over the sensitivity and specificity of this approach to define treatment failure and the delay in returning results to the clinic. We use modelling to synthesize evidence and evaluate the cost-effectiveness of viral-load-informed differentiated care, accounting for limitations of dried blood sample testing. We find that viral-load-informed differentiated care using dried blood sample testing is cost-effective and is a recommended strategy for patient monitoring, although further empirical evidence as the approach is rolled out would be of value. We also explore the potential benefits of point-of-care viral load tests that may become available in the future.