Zachary Wagner

Dr. Zachary Wagner


Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 December 2023 in Nature
Verified
Journal Article
Closed access
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RJRenzhi Jing
Renzhi Jing
SHSam Heft-Neal
Sam Heft-Neal
DCDaniel R. Chavas
Daniel R. Chavas
MGMax Griswold
Max Griswold
ZWZetianyu Wang
Zetianyu Wang
ZWZachary Wagner
Zachary Wagner

20 September 2021 in JAIDS Journal of Acquired Immune Deficiency Syndromes
Verified
Journal Article
Closed access
ZWZachary Wagner
Zachary Wagner
BMBarbara Mukasa
Barbara Mukasa
JNJosephine Nakakande
Josephine Nakakande
CSChad Stecher
Chad Stecher
USUzaib Saya
Uzaib Saya
SLSebastian Linnemayr
Sebastian Linnemayr
Introduction: Recent studies project thousands of additional AIDS-related deaths because of COVID-19–related disruptions in HIV care. However, the extent to which disruptions in care have materialized since the start of the pandemic is not well understood. Methods: We use electronic health records to investigate how the pandemic has affected clinic visits, patients' antiretroviral therapy (ART) supply, and viral suppression for a cohort of 14,632 HIV clients from a large HIV clinic in Kampala, Uganda. We complement this with an analysis of electronically measured longitudinal ART adherence data from a subcohort of 324 clients. Results: Clinic visits decreased by more than 50% after a national lockdown started. The risk of patients running out of ART on a given day increased from 5% before the lockdown to 25% 3 months later (Relative Risk Ratio of 5.11, 95% confidence interval: 4.99 to 5.24) and remained higher than prelockdown 6 months later at 13% (Relative Risk Ratio of 2.60; 95% confidence interval: 2.52 to 2.70). There was no statistically significant change in electronically measured adherence or viral suppression. Conclusion: We document substantial gaps in HIV care after the start of the COVID-19 pandemic in Uganda. This suggests that measures to improve access should be explored as the pandemic persists. However, ART adherence was unaffected for the subcohort for whom we measured electronic adherence. This suggests that some clients may have stockpiles of ART tablets from previous prescriptions that allowed them to keep taking their medication even when they could not visit the clinic for ART refills.

24 February 2020 in BMC Infectious Diseases
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Journal Article
Open access
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SMSarah MacCarthy
Sarah MacCarthy
ZWZachary Wagner
Zachary Wagner
AMAlexandra Mendoza-Graf
Alexandra Mendoza-Graf
CGCarlos Ignacio Gutierrez
Carlos Ignacio Gutierrez
CSClare Samba
Clare Samba
SLSebastian Linnemayr
Sebastian Linnemayr
Background: Studies report serious adherence problems among youth (individuals age 15–24 years of age) in Uganda. Recent growth in mobile phone ownership has highlighted the potential of using text-based interventions to improve antiretroviral treatment (ART) adherence among Ugandan youth. We piloted a randomized controlled trial of a text-based intervention providing weekly real-time antiretroviral adherence feedback, based on information from a smart pill box, to HIV-positive Ugandan youth. In this paper, we report the acceptability, feasibility, and preliminary impact of the intervention.Methods: We randomized participants to a control group, or to receive messages with information on either their own adherence levels (Treatment 1 - T1), or their own adherence and peer adherence levels (Treatment 2 – T2). We conducted six focus groups from December 2016 to March 2017 with providers and youth ages 15–24, double coded 130 excerpts, and achieved a pooled Cohen’s Kappa of 0.79 and 0.80 based on 34 randomly selected excerpts.Results: The quantitative and qualitative data show that the intervention was deemed acceptable and feasible. After controlling for baseline adherence, the T1 group had 3.8 percentage point lower adherence than the control group (95% CI -9.9, 2.3) and the T2 group had 2.4 percentage points higher adherence than the control group (95% CI -3.0, 7.9). However, there was an increasing treatment effect over time for the T2 group with the largest effect towards the end of the study; a 2.5 percentage point increase in the initial 9-weeks that grows steadily to 9.0 percentage points by the last 9-weeks of the study. We find negative treatment effects for T1 in 3 of the 4 9-week intervals. This pilot study was not designed to detect statistically significant differences.Conclusions: Improving youth’s adherence by supplementing information about their adherence with information about the adherence of peers is a promising new strategy that should be further evaluated in a fully-powered study. Providing one’s own adherence information alone appears to have less potential.Trial registration: NCT0251435607/30/2015.


24 January 2019 in PLOS Medicine
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Journal Article
Open access
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ZWZachary Wagner
Zachary Wagner
JAJohn Bosco Asiimwe
John Bosco Asiimwe
WDWilliam H. Dow
William H. Dow
DLDavid I. Levine
David I. Levine
Over half a million children die each year of diarrheal illness, although nearly all deaths could be prevented with oral rehydration salts (ORS). The literature on ORS documents both impressive health benefits and persistent underuse. At the same time, little is known about why ORS is underused and what can be done to increase use. We hypothesized that price and inconvenience are important barriers to ORS use and tested whether eliminating financial and access constraints increases ORS coverage. In July of 2016, we recruited 118 community health workers (CHWs; representing 10,384 households) in Central and Eastern Uganda to participate in the study. Study villages were predominantly peri-urban, and most caretakers had no more than primary school education. In March of 2017, we randomized CHWs to one of four methods of ORS distribution: (1) free delivery of ORS prior to illness (free and convenient); (2) home sales of ORS prior to illness (convenient only); (3) free ORS upon retrieval using voucher (free only); and (4) status quo CHW distribution, where ORS is sold and not delivered (control). CHWs offered zinc supplements in addition to ORS in all treatment arms (free in groups 1 and 3 and for sale in group 2), following international treatment guidelines. We used household surveys to measure ORS (primary outcome) and ORS + zinc use 4 weeks after the interventions began (between April and May 2017). We assessed impact using an intention-to-treat (ITT) framework. During follow-up, we identified 2,363 child cases of diarrhea within 4 weeks of the survey (584 in free and convenient [25.6% of households], 527 in convenient only [26.1% of households], 648 in free only [26.8% of households], and 597 in control [28.5% of households]). The share of cases treated with ORS was 77% (448/584) in the free and convenient group, 64% (340/527) in the convenient only group, 74% (447/648) in the free only group, and 56% (335/597) in the control group. After adjusting for potential confounders, instructing CHWs to provide free and convenient distribution increased ORS coverage by 19 percentage points relative to the control group (95% CI 13–26; P < 0.001), 12 percentage points relative to convenient only (95% CI 6–18; P < 0.001), and 2 percentage points (not significant) relative to free only (95% CI −4 to 8; P = 0.38). Effect sizes were similar, but more pronounced, for the use of both ORS and zinc. Limitations include short follow-up period, self-reported outcomes, and limited generalizability. Most caretakers of children with diarrhea in low-income countries seek care in the private sector where they are required to pay for ORS. However, our results suggest that price is an important barrier to ORS use and that switching to free distribution by CHWs substantially increases ORS coverage. Switching to free distribution is low-cost, easily scalable, and could substantially reduce child mortality. Convenience was not important in this context. Trial registry number AEARCTR-0001288.

1 June 2015 in Health Affairs
Verified
Journal Article
Closed access
ZWZachary Wagner
Zachary Wagner
JBJeremy Barofsky
Jeremy Barofsky
NSNeeraj Sood
Neeraj Sood
The President’s Emergency Plan for AIDS Relief (PEPFAR) has provided billions of US tax dollars to expand HIV treatment, care, and prevention programs in sub-Saharan Africa. This investment has gen...