Zeynep received her MS degree in Industrial Engineering from Bogazici University in 2023, and her BS degree in Industrial Engineering from Istanbul Technical University in 2019. She specializes in system science and simulation modeling for public health problems.
Her current work includes developing system dynamics models for quality of life in cancer immunotherapy, colorectal cancer screening, and opioid use disorder. She is currently working with Dr. Mohammad Jalali (“MJ”).
Selected Publications
Wongseree, Peeradon; Hasgul, Zeynep; Jalali, Mohammad S
Cost-Effectiveness of Increasing Access to Colorectal Cancer Diagnosis: Analysis From Thailand Journal Article
In: Value Health Reg Issues, vol. 43, pp. 101010, 2024, ISSN: 2212-1102.
@article{pmid38848611,
title = {Cost-Effectiveness of Increasing Access to Colorectal Cancer Diagnosis: Analysis From Thailand},
author = {Peeradon Wongseree and Zeynep Hasgul and Mohammad S Jalali},
doi = {10.1016/j.vhri.2024.101010},
issn = {2212-1102},
year = {2024},
date = {2024-06-01},
journal = {Value Health Reg Issues},
volume = {43},
pages = {101010},
abstract = {OBJECTIVES: The purpose of this study is to evaluate the cost-effectiveness of increasing access to colorectal cancer (CRC) diagnosis, considering resource limitations in Thailand.nnMETHODS: We analyzed the cost-effectiveness of increasing access to fecal immunochemical test screening (strategy I), symptom evaluation (strategy II), and their combination through healthcare and societal perspectives using Colo-Sim, a simulation model of CRC care. We extended our analysis by adding a risk-stratification score (RS) to the strategies. We analyzed all strategies under the currently limited annual colonoscopy capacity and sufficient capacity. We estimated quality-adjusted life-years (QALYs) and costs over 2023 to 2047 and performed sensitivity analyses.nnRESULTS: Annual costs for CRC care will increase over 25 years in Thailand, resulting in a cumulative cost of 323B Thai baht (THB). Each strategy results in higher QALYs gained and additional costs. With the current colonoscopy capacity and willingness-to-pay threshold of 160 000 THB, strategy I with and without RS is not cost-effective. Strategy II + RS is the most cost-effective, resulting in 0.68 million QALYs gained with additional costs of 66B THB. Under sufficient colonoscopy capacity, all strategies are deemed cost-effective, with the combined approach (strategy I + II + RS) being the most favorable, achieving the highest QALYs (1.55 million) at an additional cost of 131 billion THB. This strategy also maintains the highest probability of being cost-effective at any willingness-to-pay threshold above 96 000 THB.nnCONCLUSIONS: In Thailand, fecal immunochemical test screening, symptom evaluation, and RS use can achieve the highest QALYs; however, boosting colonoscopy capacity is essential for cost-effectiveness.},
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pubstate = {published},
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OBJECTIVES: The purpose of this study is to evaluate the cost-effectiveness of increasing access to colorectal cancer (CRC) diagnosis, considering resource limitations in Thailand.nnMETHODS: We analyzed the cost-effectiveness of increasing access to fecal immunochemical test screening (strategy I), symptom evaluation (strategy II), and their combination through healthcare and societal perspectives using Colo-Sim, a simulation model of CRC care. We extended our analysis by adding a risk-stratification score (RS) to the strategies. We analyzed all strategies under the currently limited annual colonoscopy capacity and sufficient capacity. We estimated quality-adjusted life-years (QALYs) and costs over 2023 to 2047 and performed sensitivity analyses.nnRESULTS: Annual costs for CRC care will increase over 25 years in Thailand, resulting in a cumulative cost of 323B Thai baht (THB). Each strategy results in higher QALYs gained and additional costs. With the current colonoscopy capacity and willingness-to-pay threshold of 160 000 THB, strategy I with and without RS is not cost-effective. Strategy II + RS is the most cost-effective, resulting in 0.68 million QALYs gained with additional costs of 66B THB. Under sufficient colonoscopy capacity, all strategies are deemed cost-effective, with the combined approach (strategy I + II + RS) being the most favorable, achieving the highest QALYs (1.55 million) at an additional cost of 131 billion THB. This strategy also maintains the highest probability of being cost-effective at any willingness-to-pay threshold above 96 000 THB.nnCONCLUSIONS: In Thailand, fecal immunochemical test screening, symptom evaluation, and RS use can achieve the highest QALYs; however, boosting colonoscopy capacity is essential for cost-effectiveness.
Deutsch, Arielle R; Frerichs, Leah; Hasgul, Zeynep; Murphey, Foster; Coleman, Addie K; Bachand, Annie Y; Bettelyoun, Arlana; Forney, Paul; Tyon, Gene; Jalali, Mohammad S
How Funding Policy Maintains Structural Inequity Within Indigenous Community-Based Organizations Journal Article
In: Health Aff (Millwood), vol. 42, no. 10, pp. 1411–1419, 2023, ISSN: 1544-5208.
@article{pmid37782860,
title = {How Funding Policy Maintains Structural Inequity Within Indigenous Community-Based Organizations},
author = {Arielle R Deutsch and Leah Frerichs and Zeynep Hasgul and Foster Murphey and Addie K Coleman and Annie Y Bachand and Arlana Bettelyoun and Paul Forney and Gene Tyon and Mohammad S Jalali},
doi = {10.1377/hlthaff.2023.00483},
issn = {1544-5208},
year = {2023},
date = {2023-10-01},
journal = {Health Aff (Millwood)},
volume = {42},
number = {10},
pages = {1411--1419},
abstract = {Despite efforts to increase investment in Indigenous health and well-being in the United States, disparities remain. The way in which health-promoting organizations are funded is one key mechanism driving the systemic, long-term health disparities experienced by Indigenous people in the US. Using Indigenous-led community-based organizations (ICBOs) that provide psychosocial care as a case study, we highlight multiple ways in which policies that regulate the external funding that ICBOs depend on must change to promote equity and allow the organizations to flourish and address unmet psychosocial needs for Indigenous community members. We use a system dynamics approach to discuss how "capability traps" arise from a misfit between external funding regulations and organizations' needs for sustainability and effective care provision. We provide suggestions for reforming funding policies that focus on improving ICBO sustainability.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Despite efforts to increase investment in Indigenous health and well-being in the United States, disparities remain. The way in which health-promoting organizations are funded is one key mechanism driving the systemic, long-term health disparities experienced by Indigenous people in the US. Using Indigenous-led community-based organizations (ICBOs) that provide psychosocial care as a case study, we highlight multiple ways in which policies that regulate the external funding that ICBOs depend on must change to promote equity and allow the organizations to flourish and address unmet psychosocial needs for Indigenous community members. We use a system dynamics approach to discuss how "capability traps" arise from a misfit between external funding regulations and organizations' needs for sustainability and effective care provision. We provide suggestions for reforming funding policies that focus on improving ICBO sustainability.
Wongseree, Peeradon; Hasgul, Zeynep; Leerapan, Borwornsom; Iramaneerat, Cherdsak; Phisalprapa, Pochamana; Jalali, Mohammad S
Dynamics of colorectal cancer screening in low and middle-income countries: A modeling analysis from Thailand Journal Article
In: Prev Med, pp. 107694, 2023, ISSN: 1096-0260.
@article{pmid37660758,
title = {Dynamics of colorectal cancer screening in low and middle-income countries: A modeling analysis from Thailand},
author = {Peeradon Wongseree and Zeynep Hasgul and Borwornsom Leerapan and Cherdsak Iramaneerat and Pochamana Phisalprapa and Mohammad S Jalali},
doi = {10.1016/j.ypmed.2023.107694},
issn = {1096-0260},
year = {2023},
date = {2023-09-01},
journal = {Prev Med},
pages = {107694},
abstract = {BACKGROUND: Low and middle-income countries face constraints for early colorectal cancer (CRC) detection, including restricted access to care and low colonoscopy capacity. Considering these constraints, we studied strategies for increasing access to early CRC detection and reducing CRC progression and mortality rates in Thailand.nnMETHODS: We developed a system dynamics model to simulate CRC death and progression trends. We analyzed the impacts of increased access to screening via fecal immunochemical test and colonoscopy, improving access to CRC diagnosis among symptomatic individuals, and their combination.nnRESULTS: Projecting the status quo (2023-2032), deaths per 100 K people increase from 87.5 to 115.4, and CRC progressions per 100 K people rise from 131.8 to 159.8. In 2032, improved screening access prevents 2.5 CRC deaths and 2.5 progressions per 100 K people, with cumulative prevented 7 K deaths and 9 K progressions, respectively. Improved symptom evaluation access prevents 7.5 CRC deaths per 100 K with no effect on progression, totaling 35 K saved lives. A combined approach prevents 9.3 deaths and 1.8 progressions per 100 K, or 41 K and 7 K cumulatively. The combined strategy prevents most deaths; however, there is a tradeoff: It prevents fewer CRC progressions than screening access improvement. Increasing the current annual colonoscopy capacity (200K) to sufficient capacity (681 K), the combined strategy achieves the best results, preventing 15.0 CRC deaths and 10.3 CRC progressions per 100 K people, or 54 K and 30 K cumulatively.nnCONCLUSION: Until colonoscopy capacity increases, enhanced screening and symptom evaluation are needed simultaneously to curb CRC deaths, albeit not the best strategy for CRC progression prevention.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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BACKGROUND: Low and middle-income countries face constraints for early colorectal cancer (CRC) detection, including restricted access to care and low colonoscopy capacity. Considering these constraints, we studied strategies for increasing access to early CRC detection and reducing CRC progression and mortality rates in Thailand.nnMETHODS: We developed a system dynamics model to simulate CRC death and progression trends. We analyzed the impacts of increased access to screening via fecal immunochemical test and colonoscopy, improving access to CRC diagnosis among symptomatic individuals, and their combination.nnRESULTS: Projecting the status quo (2023-2032), deaths per 100 K people increase from 87.5 to 115.4, and CRC progressions per 100 K people rise from 131.8 to 159.8. In 2032, improved screening access prevents 2.5 CRC deaths and 2.5 progressions per 100 K people, with cumulative prevented 7 K deaths and 9 K progressions, respectively. Improved symptom evaluation access prevents 7.5 CRC deaths per 100 K with no effect on progression, totaling 35 K saved lives. A combined approach prevents 9.3 deaths and 1.8 progressions per 100 K, or 41 K and 7 K cumulatively. The combined strategy prevents most deaths; however, there is a tradeoff: It prevents fewer CRC progressions than screening access improvement. Increasing the current annual colonoscopy capacity (200K) to sufficient capacity (681 K), the combined strategy achieves the best results, preventing 15.0 CRC deaths and 10.3 CRC progressions per 100 K people, or 54 K and 30 K cumulatively.nnCONCLUSION: Until colonoscopy capacity increases, enhanced screening and symptom evaluation are needed simultaneously to curb CRC deaths, albeit not the best strategy for CRC progression prevention.
Stringfellow, Erin J; Lim, Tse Yang; DiGennaro, Catherine; Hasgul, Zeynep; Jalali, Mohammad S
Enumerating contributions of fentanyls and other factors to the unprecedented 2020 rise in opioid overdose deaths: model-based analysis Journal Article
In: PNAS Nexus, vol. 2, no. 4, pp. pgad064, 2023, ISSN: 2752-6542.
@article{pmid37020497,
title = {Enumerating contributions of fentanyls and other factors to the unprecedented 2020 rise in opioid overdose deaths: model-based analysis},
author = {Erin J Stringfellow and Tse Yang Lim and Catherine DiGennaro and Zeynep Hasgul and Mohammad S Jalali},
doi = {10.1093/pnasnexus/pgad064},
issn = {2752-6542},
year = {2023},
date = {2023-04-01},
journal = {PNAS Nexus},
volume = {2},
number = {4},
pages = {pgad064},
abstract = {In 2020, the ongoing US opioid overdose crisis collided with the emerging COVID-19 pandemic. Opioid overdose deaths (OODs) rose an unprecedented 38%, due to a combination of COVID-19 disrupting services essential to people who use drugs, continued increases in fentanyls in the illicit drug supply, and other factors. How much did these factors contribute to increased OODs? We used a validated simulation model of the opioid overdose crisis, SOURCE, to estimate excess OODs in 2020 and the distribution of that excess attributable to various factors. Factors affecting OODs that could have been disrupted by COVID-19, and for which data were available, included opioid prescribing, naloxone distribution, and receipt of medications for opioid use disorder. We also accounted for fentanyls' presence in the heroin supply. We estimated a total of 18,276 potential excess OODs, including 1,792 lives saved due to increases in buprenorphine receipt and naloxone distribution and decreases in opioid prescribing. Critically, growth in fentanyls drove 43% (7,879) of the excess OODs. A further 8% is attributable to first-ever declines in methadone maintenance treatment and extended-released injectable naltrexone treatment, most likely due to COVID-19-related disruptions. In all, 49% of potential excess OODs remain unexplained, at least some of which are likely due to additional COVID-19-related disruptions. While the confluence of various COVID-19-related factors could have been responsible for more than half of excess OODs, fentanyls continued to play a singular role in excess OODs, highlighting the urgency of mitigating their effects on overdoses.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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In 2020, the ongoing US opioid overdose crisis collided with the emerging COVID-19 pandemic. Opioid overdose deaths (OODs) rose an unprecedented 38%, due to a combination of COVID-19 disrupting services essential to people who use drugs, continued increases in fentanyls in the illicit drug supply, and other factors. How much did these factors contribute to increased OODs? We used a validated simulation model of the opioid overdose crisis, SOURCE, to estimate excess OODs in 2020 and the distribution of that excess attributable to various factors. Factors affecting OODs that could have been disrupted by COVID-19, and for which data were available, included opioid prescribing, naloxone distribution, and receipt of medications for opioid use disorder. We also accounted for fentanyls' presence in the heroin supply. We estimated a total of 18,276 potential excess OODs, including 1,792 lives saved due to increases in buprenorphine receipt and naloxone distribution and decreases in opioid prescribing. Critically, growth in fentanyls drove 43% (7,879) of the excess OODs. A further 8% is attributable to first-ever declines in methadone maintenance treatment and extended-released injectable naltrexone treatment, most likely due to COVID-19-related disruptions. In all, 49% of potential excess OODs remain unexplained, at least some of which are likely due to additional COVID-19-related disruptions. While the confluence of various COVID-19-related factors could have been responsible for more than half of excess OODs, fentanyls continued to play a singular role in excess OODs, highlighting the urgency of mitigating their effects on overdoses.