I apply methods from operations research, epidemiology, machine learning and economics to model healthcare decisions. My work aims to inform clinical practice and health policy. I've evaluated interventions in gastroenterology and developed tools to detect and manage kidney disease in children. My dissertation focuses on the safe collection and transfusion of donated blood.
I am a PhD candidate in Management Science & Engineering at Stanford University. For the 2019-20 academic year, I am visiting McGill University as a graduate research trainee in Clinical & Health Informatics.
Clipping Over the Scope for Recurrent Peptic Ulcer Bleeding is Cost-Effective as Compared to Standard Therapy: An Initial Assessment.
Gastrointestinal endoscopy clinics of North America
2020; 30 (1): 91–97
Clipping over the scope (C-OTS) is a novel closure technique used for the treatment of nonvariceal gastrointestinal bleeding, especially for high-risk lesions. C-OTS devices cost more than clipping through the scope and thermal devices. The high upfront cost of C-OTS may pose a barrier to its use and the cost-effectiveness of C-OTS for peptic ulcer disease bleeding is unknown. Cost-effectiveness studies of C-OTS for peptic ulcer bleeding as both first-line and second-line therapy can provide the current estimate of the conditions in which the use of C-OTS is cost-effective and give insights of the determinants to the cost-effectiveness of C-OTS.
View details for DOI 10.1016/j.giec.2019.09.004
View details for PubMedID 31739969
Active testing of groups at increased risk of acquiring SARS-CoV-2 in Canada: costs and human resource needs.
CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne
Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is largely passive, which impedes epidemic control. We defined active testing strategies for SARS-CoV-2 using reverse transcription polymerase chain reaction (RT-PCR) for groups at increased risk of acquiring SARS-CoV-2 in all Canadian provinces.We identified 5 groups who should be prioritized for active RT-PCR testing: contacts of people who are positive for SARS-CoV-2, and 4 at-risk populations - hospital employees, community health care workers and people in long-term care facilities, essential business employees, and schoolchildren and staff. We estimated costs, human resources and laboratory capacity required to test people in each group or to perform surveillance testing in random samples.During July 8-17, 2020, across all provinces in Canada, an average of 41 751 RT-PCR tests were performed daily; we estimated this required 5122 personnel and cost $2.4 million per day ($67.8 million per month). Systematic contact tracing and testing would increase personnel needs 1.2-fold and monthly costs to $78.9 million. Conducted over a month, testing all hospital employees would require 1823 additional personnel, costing $29.0 million; testing all community health care workers and persons in long-term care facilities would require 11 074 additional personnel and cost $124.8 million; and testing all essential employees would cost $321.7 million, requiring 25 965 added personnel. Testing the larger population within schools over 6 weeks would require 46 368 added personnel and cost $816.0 million. Interventions addressing inefficiencies, including saliva-based sampling and pooling samples, could reduce costs by 40% and personnel by 20%. Surveillance testing in population samples other than contacts would cost 5% of the cost of a universal approach to testing at-risk populations.Active testing of groups at increased risk of acquiring SARS-CoV-2 appears feasible and would support the safe reopening of the economy and schools more broadly. This strategy also appears affordable compared with the $169.2 billion committed by the federal government as a response to the pandemic as of June 2020.
View details for DOI 10.1503/cmaj.201128
View details for PubMedID 32907820
Baseline creatinine determination method impacts association between acute kidney injury and clinical outcomes.
Pediatric nephrology (Berlin, Germany)
Current consensus definition for acute kidney injury (AKI) does not specify how baseline serum creatinine should be determined. We assessed how baseline determination impacted AKI incidence and association between AKI and clinical outcomes.We retrospectively applied empirical (measured serum creatinine) and imputed (age/height) baseline estimation methods to pediatric patients discharged between 2014 and 2019 from an academic hospital. Using each method, we estimated AKI incidence and assessed area under ROC curve (AUROC) for AKI as a predictor of three clinical outcomes: application of AKI billing code (proxy for more clinically overt disease), inpatient mortality, and post-hospitalization chronic kidney disease.Incidence was highly variable across baseline methods (12.2-26.7%). Incidence was highest when lowest pre-admission creatinine was used if available and Schwartz bedside equation was used to impute one otherwise. AKI was more predictive of application of an AKI billing code when baseline was imputed universally, regardless of pre-admission values (AUROC 80.7-84.9%) than with any empirical approach (AUROC 64.5-76.6%). AKI was predictive of post-hospitalization CKD when using universal imputation baseline methods (AUROC 67.0-74.6%); AKI was not strongly predictive of post-hospitalization CKD when using empirical baseline methods (AUROC 46.4-58.5%). Baseline determination method did not affect the association between AKI and inpatient mortality.Method of baseline determination influences AKI incidence and association between AKI and clinical outcomes, illustrating the need for standard criteria. Imputing baseline for all patients, even when preadmission creatinine is available, may identify a more clinically relevant subset of the disease.
View details for DOI 10.1007/s00467-020-04789-9
View details for PubMedID 33095322
Cost Effectiveness of Endoscopic Resection vs Transanal Resection of Complex Benign Rectal Polyps.
Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association
BACKGROUND & AIMS: Complex benign rectal polyps can be managed with transanal surgery or with endoscopic resection (ER). Though the complication rate after ER is lower than transanal surgery, recurrence is higher. Patients lost to follow up after ER might therefore be at increased risk for rectal cancer. We evaluated the costs, benefits, and cost effectiveness of ER compared to 2 surgical techniques for removing complex rectal polyps, using a 50-year time horizon-this allowed us to capture rates of cancer development among patients lost from follow-up surveillance.METHODS: We created a Markov model to simulate the lifetime outcomes and costs of ER, transanal endoscopic microsurgery (TEM), and transanal minimally invasive surgery (TAMIS) for the management of a complex benign rectal polyp. We assessed the effect of surveillance by allowing a portion of the patients to be lost to follow up. We calculated the cost, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio or each intervention over a 50-year time horizon.RESULTS: We found that TEM was slightly more effective than TAMIS and ER (TEM, 19.54 QALYs; TAMIS, 19.53 QALYs; and ER19.53, QALYs), but ER had a lower lifetime discounted cost (ER cost $7161, TEM cost $10,459, and TAMIS cost $11,253). TEM was not cost effective compared to ER, with an incremental cost-effectiveness ratio of $485,333/QALY. TAMIS was ruled out by extended dominance. TEM became cost effective when the mortality from ER exceeded 0.63%, or if loss to follow up exceeded 25.5%.CONCLUSIONS: Using a Markov model, we found that ER, TEM, and TAMIS have similar effectiveness, but ER is less expensive, in management of benign rectal polyps. As the rate of loss to follow up increases, transanal surgery becomes more effective relative to ER.
View details for PubMedID 30849517
Screening the Blood Supply for Zika Virus in the 50 U.S. States and Puerto Rico: A Cost-Effectiveness Analysis.
Annals of internal medicine
In 2016, universal individual donation nucleic acid testing (ID-NAT) of donated blood for Zika virus began in U.S. states and territories.To assess the cost-effectiveness of universal ID-NAT in the first year of screening compared with alternatives for the 50 states and separately for Puerto Rico.Microsimulation that captured Zika-related harms to transfusion recipients, sexual partners, and their infants.National testing results compiled by AABB and costs, utilities, and outcome probabilities estimated from the literature.Transfusion recipients.Lifetime.Societal.Universal ID-NAT, universal mini-pool NAT (MP-NAT), and ID-NAT exclusively for components transfused to women of childbearing age. Seasonally targeted strategies in Puerto Rico and geographically targeted strategies in the 50 states were also considered.Costs, quality-adjusted life-years (QALYs), and outcomes.In Puerto Rico, MP-NAT exclusively during high mosquito season was cost-effective at $81 123 per QALY (95% CI, -$49 138 to $978 242 per QALY). No screening policy was cost-effective in the 50 states. Universal ID-NAT cost $341 million per QALY (CI, $125 million to $2.90 billion per QALY) compared with no screening in the 50 states.In Puerto Rico, MP-NAT only during the season of high mosquito activity was most cost-effective in 64% of probabilistic sensitivity analysis iterations. In the 50 states, no intervention was cost-effective in 99.99% of iterations. Cost-effectiveness was highly dependent on the rate of assumed infectious donations.Data were limited on the component-specific transmissibility of Zika and long-term sequelae of infection.Screening was cost-effective only in the high mosquito season in Puerto Rico, and no evaluated screening policy was cost-effective in the 50 states. During periods with lower rates of Zika-infectious donations, the cost-effectiveness of screening will be even less favorable.None.
View details for PubMedID 30615781