Ljubica (LJ) Ristovska

P.S. My full name is pronounced LYOO-bee-tsa REES-tov-skah, but feel free to call me LJ.

I am on the 2024-2025 job market.

I am a postdoctoral associate at the Tobin Center for Economic Policy at the Economics Department at Yale University. I received my Ph.D. in Economics from Harvard University in 2023.

My research focuses on health economics, particularly innovation, adoption, and use of pharmaceuticals and treatments, as well as the organization of health care teams. I also have work examining socio-economic determinants of health.

You can contact me at ljubica.ristovska@yale.edu.

References

David Cutler

Harvard University

dcutler@fas.harvard.edu

Mark Shepard

Harvard University

mark_shepard@hks.harvard.edu

Jason Abaluck

Yale University

jason.abaluck@yale.edu

Zack Cooper

Yale University

zack.cooper@yale.edu

Working papers

[JOB MARKET PAPER] Informative Ordeals in Healthcare: Prior Authorization of Drugs in Medicaid (draft coming soon)

with Samantha Burn

Drug Adoption under Uncertain Quality and Impact of FDA (De)Certiﬁcation

[Paper]

Racial Disparities in COVID-19 Cases and Deaths: Theories and Evidence

[Paper]

Human Capital Spillovers and Health: Does Living Around College Graduates Lengthen Life? (under review)

with Jacob Bor, David Cutler and Edward Glaeser

[Paper] [NBER working paper] [Harvard Gazette] [NBER Bulletin on Health] [Twitter summary thread]

Work in progress

Instrumental Variable Methods Reveal Large Risks of Menopausal Hormone Therapy in the Landmark Women’s Health Initiative Clinical Trial (draft coming soon)

with Josh Angrist, Amanda Kowalski and Marcia Stefanick

Evaluating state policies to regulate healthcare spending (draft coming soon)

with Zack Cooper

Staff Composition and Patient Outcomes at Nursing Homes

with Ashvin Gandhi, David Grabowski and Brian McGarry

Regional variation in health care prices

with Mai Anh Tran, Stuart Craig and Zack Cooper

Publications

Impact of Symptomatic Skeletal Events on Healthcare Resource Utilization and Quality of Life Among Patients with Castration-Resistant Prostate Cancer and Bone Metastases

with Rana McKay, Batool Haider, Mei Duh, Adriana Valderrama, Mari Nakabayashi, Matthew Fiorillo, Lonnie Wen and Philip Kantoff

Prostate Cancer and Prostatic Diseases; 20, p. 276-282, 2017.

[Paper]

Background: Data regarding the impact of symptomatic skeletal events (SSEs) on health economics and patient-reported outcomes in men with castration-resistant prostate cancer (CRPC) and bone metastases from a clinical setting are lacking. Hence, this study aimed to quantify the effects of SSEs on health-care resource utilization (HRU), health-related quality of life (HRQoL) and pain in men with CRPC metastasized to bone.

Methods: This cohort study included men with CRPC and bone metastasis treated at a tertiary center during December 1996–July 2015. SSEs, including pathological fracture, radiation to bone, spinal cord compression and bone surgery, as well as HRU were identified retrospectively through medical records and clinical database. A subset of surviving patients completed Functional Assessment of Cancer Therapy-Prostate (FACT-P) and Brief Pain Inventory-Short Form (BPI-SF) questionnaires. The incremental effect of SSEs on HRU was evaluated using multivariable generalized linear regression. Questionnaire scores were compared using effect sizes (ES); ES⩾0.33 indicated meaningful differences between SSE and non-SSE cohorts. Lower scores suggest lower HRQoL and pain.

Results: Of the 832 patients, 207 developed ⩾1 SSE (mean 1.5±0.8) during follow-up (median 2.1 years). Radiation to bone was the most common SSE (84.1%). SSE cohort had significantly higher emergency room (incidence rate ratio (IRR)=1.48; P=0.006), outpatient (IRR=1.17; P=0.005) and inpatient (IRR=1.74; P<0.001) visits. Of the 107 eligible survey patients, 103 (96.3%) responded. SSE cohort had lower mean FACT-P functional well-being (17.5 vs 19.8; P=0.158; ES=0.36), higher mean pain severity (2.5 vs 1.6; P=0.048; ES=0.47) and worst pain scores (3.6 vs 2.3; P=0.033; ES=0.50) compared with the non-SSE cohort, indicating meaningful differences between cohorts.

Conclusions: This study demonstrated high economic and HRQoL burden of SSEs. The findings underscore the need for better supportive and disease-modifying treatments for these patients.

Functional Limitations and Health Care Resource Utilization for Individuals with Cognitive Impairment without Dementia: Findings from a US Population-Based Survey

with J. Scott Andrews, Urvi Desai, Noam Kirson, Caroline Enloe, Sarah King, Howard Birnbaum, Adam Fleisher, Wenyu Ye and Kristin Kahle-Wrobleski

Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring; 6, p. 65-74, 2017.

[Paper]

Assessing the Economic Burden of Alzheimer’s Disease Patients First Diagnosed by Specialists

with Noam Kirson, Urvi Desai, Alice Kate Cummings, Howard Birnbaum, Wenyu Ye, Scott Andrews, Daniel Ball and Kristin Kahle-Wrobleski

BMC Geriatrics; 16(138), published online, 2016.

[Paper]

Background: It is not known if there is a differential impact on Alzheimer’s disease (AD) diagnosis and outcomes if/when patients are diagnosed with cognitive decline by specialists versus non-specialists. This study examined the cost trajectories of Medicare beneficiaries initially diagnosed by specialists compared to similar patients who received their diagnosis in primary care settings.

Methods: Patients with ≥2 claims for AD were selected from de-identified administrative claims data for US Medicare beneficiaries (5 % random sample). The earliest observed diagnosis of cognitive decline served as the index date. Patients were required to have continuous Medicare coverage for ≥12 months pre-index (baseline) and ≥12 months following the first AD diagnosis, allowing for up to 3 years from index to AD diagnosis. Time from index date to AD diagnosis was compared between those diagnosed by specialists (i.e., neurologist, psychiatrist, or geriatrician) versus non-specialists using Kaplan-Meier analyses with log-rank tests. Patient demographics, Charlson Comorbidity Index (CCI) during baseline, and annual all-cause medical costs (reimbursed by Medicare) in baseline and follow-up periods were compared across propensity-score matched cohorts.

Results: Patients first diagnosed with cognitive decline by specialists (n = 2593) were younger (78.8 versus 80.8 years old), more likely to be male (40 % versus 34 %), and had higher CCI scores and higher medical costs at baseline than those diagnosed by non-specialists (n = 13,961). However, patients diagnosed by specialists had a significantly shorter time to AD diagnosis, both before and after matching (mean [after matching]: 3.5 versus 4.6 months, p < 0.0001). In addition, patients diagnosed by specialists had significantly lower average total all-cause medical costs in the first 12 months after their index date, a finding that persisted after matching ($19,824 versus $25,863, p < 0.0001). Total per-patient annual medical costs were similar for the two groups starting in the second year post-index.

Conclusions: Before and after matching, patients diagnosed by a specialist had a shorter time to AD diagnosis and incurred lower costs in the year following the initial cognitive decline diagnosis. Differences in costs converged during subsequent years. This suggests that seeking care from specialists may yield more timely diagnosis, appropriate care and reduced costs among those with cognitive decline.

Economic Outcomes among Medicare Patients Receiving Bioengineered Cellular Technologies for Treatment of Diabetic Foot Ulcers

with J. Bradford Rice, Urvi Desai, Alice Kate Cummings, Howard Birnbaum, Michelle Skornicki, David Margolis and Nathan Parsons

Journal of Medical Economics; 18(8), p. 586-595, published online, 2015.

[Paper]

Objective: To assess the real-world medical services utilization and associated costs of Medicare patients with diabetic foot ulcers (DFUs) treated with Apligraf (bioengineered living cellular construct (BLCC)) or Dermagraft (human fibroblast-derived dermal substitute (HFDS)) compared with those receiving conventional care (CC).

Methods: DFU patients were selected from Medicare de-identified administrative claims using ICD-9-CM codes. The analysis followed an ‘intent-to-treat’ design, with cohorts assigned based on use of (1) BLCC, (2) HFDS, or (3) CC (i.e., ≥1 claim for a DFU-related treatment procedure or podiatrist visit and no evidence of skin substitute use) for treatment of DFU in 2006–2012. Propensity score models were used to separately match BLCC and HFDS patients to CC patients with similar baseline demographics, wound severity, and physician experience measures. Medical resource use, lower-limb amputation rates, and total healthcare costs (2012 USD; from payer perspective) during the 18 months following treatment initiation were compared among the resulting matched samples.

Results: Data for 502 matched BLCC-CC patient pairs and 222 matched HFDS-CC patient pairs were analyzed. Increased costs associated with outpatient service utilization relative to matched CC patients were offset by lower amputation rates (−27.6% BLCC, −22.2% HFDS), fewer days hospitalized (−33.3% BLCC, −42.4% HFDS), and fewer emergency department visits (−32.3% BLCC, −25.7% HFDS) among BLCC/HFDS patients. Consequently, BLCC and HFDS patients had per-patient average healthcare costs during the 18-month follow-up period that were lower than their respective matched CC counterparts (−$5253 BLCC, −$6991 HFDS).

Limitations: Findings relied on accuracy of diagnosis and procedure codes contained in the claims data, and did not account for outcomes and costs beyond 18 months after treatment initiation.

Conclusion: These findings suggest that use of BLCC and HFDS for treatment of DFU may lower overall medical costs through reduced utilization of costly healthcare services.

Other writing

Regulations and Data Sources on Pediatric Clinical Studies in the United States and European Union

National Bureau of Economic Research and Institute for Fiscal Studies Network on the Value of Medical Research; published online, 2020.

[Paper]

Political Consensus for the Economic Future of Republic of Macedonia (book; in Macedonian)

with Marjan Nikolov, Borce Trenovski and Hristijan Ristovski

Open Society Institute; published online, 2013.