About

Gaby Markle ’26 is a student involved in research related to improving therapeutics for Type 1 diabetes through synthetic biology, working with Cornell CALS biological and environmental engineering professor Minglin Ma. Her work focuses on developing potential treatments for diabetes, exemplifying the department's emphasis on innovative biological research. The department of Molecular Biology and Genetics at CALS offers a variety of research opportunities, supporting students in conducting groundbreaking work that contributes to advancements in health and environmental sciences.

Research topics

• Internal medicine
• Medicine
• Psychiatry
• Emergency medicine
• Environmental health

Selected publications

• Cost-effectiveness of a peer-delivered behavioral intervention for adherence to antiretroviral therapy and alcohol and drug use in South African HIV care

  AIDS Care · 2026-01-22

  articleSenior author

  ClinicalTrials.gov identifier: NCT03529409.

  PublisherDOI

• Making Implementation Costing More Accessible: Initial Transdisciplinary Guidance for Researchers and Practitioners

  Implementation Research and Practice · 2026-04-01

  articleOpen access

  Introduction: to conduct implementation cost evaluations. Recommendations, tools, and examples are needed to incorporate reliable and feasible costing approaches into implementation studies and guidance on when an economist is necessary. To this end, we identified key issues and developed this paper and a guide on pragmatic approaches for assessing and reporting implementation costs. Method: We assembled a team of implementation scientists and health economists working in various settings to identify central issues related to implementation costing. Our objective was to support the broad application of costing in implementation studies that is consistent, feasible, and can be practically applied. We engaged in a limited, iterative process of developing initial guidelines and soliciting feedback, consistent with principles of USE-EBPI (Usability Evaluation for Evidence-Based Psychosocial Interventions) methodology, to make refinements and enhance broad applicability. Results: We developed initial recommendations for a limited number of critical issues to advance the application of costing in implementation science and illustrated them using a study example. These issues were: (a) identifying relevant resource costs, (b) capturing resources using activity-based costing (ABC), (c) valuing resource units, summarizing and reporting, and (d) estimating replication and sustainment costs. We also emphasize the need to tailor approaches to meet different contexts and project-specific needs, and provide guidance when additional help may be needed. Conclusions: Key to ensuring any program's successful adoption, implementation, and sustainment is understanding the costs and resources required. Costing implementation in the "real world" is both an art and a science; teams must make decisions about give-and-take related to precision and burden on participants and the research team while still producing generalizable estimates. Transdisciplinary costing guidance can address these issues and provide details and resources to help pragmatically cost and report implementation efforts.

  PublisherDOI

• Health-Related Quality of Life Profiles of Individuals With a History of Opioid Use Disorder by Intensity of Criminal-Legal System Involvement

  Drug and Alcohol Dependence · 2025-02-01

  articleSenior author
  PublisherDOI

• Health and Economic Outcomes of Addressing Encampments of Individuals Using Opioids

  JAMA Network Open · 2025-06-27 · 2 citations

  articleOpen access

  Importance: Many US communities face a crisis of people experiencing unsheltered homelessness often intertwined with opioid use. Jurisdictions seek policy options for managing unsanctioned encampments of this population, but their various outcomes are unclear. Objective: To evaluate policy options and their health and economic outcomes for an encampment of people experiencing homelessness and opioid use disorder (OUD). Design, Setting, and Participants: This decision analytical model study conducted a closed-cohort state-transition simulation using the Researching Effective Strategies to Prevent Opioid Death (RESPOND) model from October 2021 to October 2022. The study was based primarily on data from Massachusetts and simulated an urban encampment with a population experiencing homelessness and high-risk opioid use. Data analysis was performed from December 2022 to October 2024. Exposure: The following encampment management strategies were modeled: (1) status quo (no sweep); (2) sweep, a sudden disruption of all residents, followed by no additional resources; (3) housing with medication for opioid use disorder (MOUD) requirement; or (4) housing without MOUD requirement. Main Outcomes and Measures: The primary outcomes were overdose and all-cause mortality per 1000 person-years, weeks spent in housing and taking MOUD, and economic cost from a modified government payer perspective. Sensitivity analyses were conducted by varying uncertain parameters. Results: The simulated cohort included 400 adults (mean [SD] age, 48 [17] years; 232 males [58.0%]). Under the status quo strategy, there were 50.4 (95% uncertainty interval [UI], 48.9-52.2) deaths per 1000 person-years, 15.5 (95% UI, 14.0-17.2) deaths from overdose per 1000 person-years, and 2990 (95% UI, 2897-3081) person-weeks spent taking MOUD for a total cost of $6 583 000 (95% UI, $6 502 000-$6 660 000). A sweep strategy resulted in 53.1 (95% UI, 51.3-55.2) deaths per 1000 person-years, 16.4 (95% UI, 18.2-20.2) deaths from overdose per 1000 person-years, and 1694 (95% UI, 1625-1764) person-weeks spent taking MOUD at a total cost of $6 820 000 (95% UI, $6 736 000-$6 899 000). The housing with medication requirement strategy resulted in 51.2 (95% UI, 49.4-53.0) deaths per 1000 person-years, 16.3 (95% UI, 14.6-18.1) deaths from overdose per 1000 person-years, and 3050 (95% UI, 3025-3075) person-weeks spent taking MOUD and in housing, for a total cost of $7 264 000 (95% UI, $7 188 000-$7 336 000). A housing without MOUD requirement strategy resulted in 49.2 (95% UI, 47.6-51.1) deaths per 1000 person-years, 14.3 (95% UI, 12.7-16.2) deaths from overdose per 1000 person-years, and 5014 (95% UI, 4942-5085) person-weeks spent taking MOUD and 14 511 (95% UI, 14 461-14 562) person-weeks spent in housing, for a total cost of $8 822 000 (95% UI, $8 774 000-$8 868 000). Conclusions and Relevance: In this decision analytical model study of approaches to homeless encampments involving individuals with OUD, sweeps increased mortality and spending. Housing without MOUD requirement was the most costly strategy but saved more lives.

  PublisherOA PDFDOI

• Cost analysis of MOUD implementation and sustainability in Massachusetts jails

  Health & Justice · 2025-02-05 · 4 citations

  articleOpen accessSenior author

  BACKGROUND: In 2018 Massachusetts mandated that county jails offer all FDA-approved medications for opioid use disorder (MOUD) to incarcerated individuals with OUD. Estimating costs needed to implement and sustain an MOUD program are not clearly known in jail facilities. The objective of this study was to identify the type of MOUD model deployed by the jails serving as research sites for the Massachusetts JCOIN hub, determine which resources were utilized at each stage of development, and estimate the associated costs. METHODS: Resources required to implement and sustain the MOUD programs were identified through detailed, site-specific microcosting analyses at six participating jails in Massachusetts. Quantitative resource utilization data were captured primarily through in-person site-visits and semi-structured interviews with key personnel. Unit costs were derived from the Federal Supply Schedule and Bureau Labor of Statistics from a site-specific level perspective. Our customizable budget impact tool, designed to assist jails/prisons with assessing the viability of alternative MOUD models, was used to organize each site's resources and estimate their associated costs. Resources/costs were summarized by site, according to type and phase, and cross-site comparisons were made to identify common program elements and unique models. RESULTS: Three MOUD models were identified. Model 1 consisted of a vendor hired to deliver and administer methadone daily, while clinical jail staff administered buprenorphine and extended-release naltrexone. Model 2 included facilities that hired a certified vendor to operate an in-house opioid treatment program (OTP) to oversee the administration of all MOUD. Jails in Model 3 became certified OTPs, thereby allowing jail staff to manage all aspects of the MOUD program. There was considerable variability in implementation costs, both within and across models, driven by model-specific factors, but also with switching models, expanding infrastructure, etc. Entering the sustainment phase, the per-person costs of care were quite similar across models but differed according to the proportion of costs considered time-dependent vs. variable. CONCLUSION: Our findings represent the most detailed and comprehensive estimates of resource/cost requirements for jail-based MOUD programs. Given the budget constraints faced by jails, the investment required to implement/sustain an MOUD program will likely result in the need to obtain additional funding or reallocate existing resources away from other initiatives.

  PublisherOA PDFDOI

• A randomized controlled trial to assess whether a telehealth-based contingency management intervention reduces alcohol use for individuals with alcohol use disorder

  Contemporary Clinical Trials · 2025-01-15 · 2 citations

  articleOpen access

  BACKGROUND: Contingency management (CM) is an intervention for alcohol use disorder (AUD) that reinforces abstinence, as confirmed by alcohol biomarkers. CM is usually brief (12-16 weeks) despite evidence that longer interventions have better long-term outcomes. Most CM models are in-person which can also be a barrier for treatment. Studies of longer duration telehealth-based CM models are needed. AIMS: To determine if a telehealth-based CM model that utilizes phosphatidylethanol (PEth) to confirm abstinence is effective at reducing alcohol use during a 26-week intervention and 12-month follow-up. We will evaluate the impact of CM on alcohol-related outcomes, determine if Addiction Neuroclinical Assessment variables are associated with outcomes in follow-up, and whether savings related to decreased alcohol use offset intervention costs. METHODS: Adults with AUD residing in the United States will be recruited via online advertising. Research procedures will be conducted virtually. Participants who submit a PEth-positive blood sample (≥20 ng/mL) at enrollment will be randomized to 26 weeks of either 1) online cognitive behavior therapy (CBT4CBT) with rewards not contingent on PEth results (Control group) or 2) CBT4CBT with a maximum of $1,820 of rewards contingent on PEth results (CM group). Efficacy outcomes of PEth-negative tests (primary) and PEth-defined excessive drinking (≥200 ng/mL; secondary) will be assessed. Predictors of intervention outcomes and economic viability will also be investigated. DISCUSSION: If this telehealth-delivered PEth-based CM intervention reduces alcohol use and is cost-effective, it could be used to provide effective treatment to millions of individuals with AUD who do not receive in-person care.

  PublisherDOI

• Association of past-year mental and physical health conditions with intentional or unintentional drug overdoses

  Journal of Substance Use and Addiction Treatment · 2025-08-24

  article
  PublisherDOI

• An economic analysis of community costs incurred to implement the communities that HEAL intervention to reduce opioid overdose deaths in four states

  Drug and Alcohol Dependence · 2025-04-17 · 2 citations

  articleOpen access
  PublisherOA PDFDOI

• Cost-Effectiveness of Linkage Case Management for Hospitalized People With HIV

  JAMA Network Open · 2025-11-05

  articleOpen accessSenior authorCorresponding

  Importance: The Daraja randomized clinical trial was a linkage case management intervention designed to improve HIV care engagement. Understanding the economic value of this type of case management intervention is essential to decision-makers in resource-constrained settings seeking to minimize HIV-related morbidity and mortality. Objective: To evaluate the cost-effectiveness of Daraja compared with enhanced standard care from the Tanzania Ministry of Health and societal perspectives. Design, Setting, and Participants: This prospective economic evaluation was conducted alongside the Daraja randomized clinical trial at 20 hospitals in Northwestern Tanzania from March 2019 to May 2023. Participants were patients hospitalized with HIV randomly assigned 1:1 to receive either the Daraja intervention or enhanced standard care and were followed up for 12 months through March 2023. Data were analyzed from May 2024 to March 2025. Exposure: The Daraja intervention group received up to 5 sessions conducted by a social worker at the hospital, in the home, and in the HIV clinic over a 3-month period. The enhanced standard care group received predischarge HIV counseling and assistance in scheduling an HIV clinic appointment. Main Outcomes and Measures: The primary outcome was the cost per disability-adjusted life-year (DALY) averted for Daraja vs standard care, assessed from Ministry of Health and societal perspectives at 3 months (intervention) and 12 months (intervention plus follow-up). Results: Among 500 participants, the mean (SD) age was 37 [12] years, and 384 participants (77%) were female. Participants in the intervention group incurred more costs from the Tanzanian Ministry of Health perspective over the 3-month intervention period ($43.4 vs $24.0; difference, $19.4 [95% CI, $9.2 to $29.6]) and over the 12-month observation period ($101.6 vs $78.2; difference, $23.4 [95% CI, $8.0 to $38.9]). From the societal perspective, Daraja incurred more costs than standard care at 3 months ($72.4 vs $47.4; difference, $25.0 [95% CI, $2.0 to $48.0]) but not 12 months ($182.7 vs $160.5; difference, $22.2 [95% CI, -$16.4 to 60.8]). DALYs were lower for Daraja participants at both the 3-month (1.2 [95% CI, 1.1 to 1.2] DALYs averted, annualized) and 12-month (1.1 [95% CI, 1.3 to 3.7] DALYs averted) time points. Conclusions and Relevance: In this economic evaluation of the Daraja intervention, Daraja was more costly than standard care from both the Tanzanian Ministry of Health and societal perspectives; however, it was associated with improvements in DALYs. These findings suggest that Daraja has a high probability of being considered cost-effective from both economic perspectives.

  PublisherOA PDFDOI

• The cost of implementing and sustaining an evidence-based, behavioral-health electronic screening system in probation departments

  Health & Justice · 2025-04-21 · 2 citations

  articleOpen accessSenior author

  BACKGROUND: Roughly 50%-75% of youths who have had contact with the juvenile justice system have a mental-health disorder. In 2019, a northeastern state required probation departments to implement an evidence-based behavioral health (BH) screen. e-Connect is a digital clinical decisional support system designed to identify suicide thoughts and behaviors and related BH risk and triage youths based on BH need, then facilitate linkage to care. OBJECTIVE: To identify the resources and estimate the costs required to implement and sustain e-Connect from probation-department and policymaker perspectives. METHODS: Prospective micro-costing analysis conducted concurrently with a rigorous evaluation of e-Connect. Data were collected for 622 youths ages 10-18 via administrative records, study instruments, and semi-structured interviews. Resources/costs were categorized as "fixed", "time-dependent", or "variable". Mean annual costs (per-county and per-screen, by county) were calculated for two intervention phases, "implementation" and "sustainment". All costs are in 2019 USD. RESULTS: The policymaker-relevant, annualized, mean, per-county start-up and sustainment costs were $18,704 (SD = $14,320) and $13,374 (SD = $13,317), respectively. The per-screen sustainment cost was $115 (SD = $113) across counties, with variation attributed to a combination of a county's behavioral-health needs, and differences in the types of resources utilized as part of their post-screening clinical response. CONCLUSION: The results of this analysis will inform the decisions of probation departments and their stakeholders, who are interested in implementing an evidence-based behavioral-health screen for youths on probation. Site-level figures will provide important details regarding the resources/costs associated with various implementation and management strategies. Cross-site, per-person averages will provide crucial inputs into budget impact models and cost-effectiveness analyses.

  PublisherOA PDFDOI

Recent grants

• Health and Economic Outcomes of Treatment with Extended-Release Naltrexone Among Pre-Release Prisoners with Opioid Use Disorder

  NIH · $1.6M · 2019–2025

• Health Economics of Substance Use Disorder, HCV, and HIV Treatment: Supporting Financial Sustainability, Advanced Methods, and Knowledge Translation

  NIH · $17.3M · 2015–2030

Frequent coauthors

• Sterling McPherson

  Georgia Highlands College

  69 shared

• Benjamin P. Linas

  66 shared

• Jake R. Morgan

  Boston University

  53 shared

• Ali Jalali

  Cornell University

  48 shared

• Bruce R. Schackman

  Cornell University

  46 shared

• Sabrina A. Assoumou

  Boston Medical Center

  43 shared

• Philip J. Jeng

  University of California, Los Angeles

  36 shared

• Kathryn E. McCollister

  31 shared

Education

• Ph.D., School of Economic Sciences

  Washington State University

Awards & honors

• Education & Professional Improvement Service Award (2013)