About

Dr. Paula Strassle is an Assistant Professor of Epidemiology at the University of Maryland. Her work focuses on identifying neighborhood, healthcare system, and individual barriers to high-quality, appropriate care for racial and ethnic minority populations and rural communities. Her current research addresses disparities across the cancer care continuum. Dr. Strassle specializes in leveraging high-dimensional healthcare data, data linkage, and advanced epidemiologic methods to conduct population health research that can inform clinical practice and reduce health disparities in marginalized populations. She is also interested in exploring the impact of bias in observational research and making complex epidemiologic methods accessible to junior researchers and clinical audiences. She holds a secondary appointment in the Department of Practice, Sciences and Health Outcomes Research at the University of Maryland School of Pharmacy and is a member of the Artificial Intelligence Interdisciplinary Institute at Maryland and the University of Maryland Marlene and Stewart Greenbaum Comprehensive Cancer Center (UMGCCC, Population Science program). Her educational background includes a PhD in Epidemiology from the University of North Carolina at Chapel Hill, an MSPH in Epidemiology from Emory University, and a BS in Psychology from the University of Maryland, Baltimore County.

Research topics

• Surgery
• Internal medicine
• Pediatrics
• Medicine
• Emergency medicine
• Demography
• Physical therapy

Selected publications

• Breast cancer mortality by age and race and/or ethnicity across counties in the United States, 2000-2019

  JNCI Journal of the National Cancer Institute · 2026-04-01

  articleOpen access

  BACKGROUND: We evaluated county-level variations in racial and/or ethnic disparities in breast cancer mortality rates across the U.S. over a 20-year period. METHODS: Validated small-area estimation models were used to calculate breast cancer mortality rates by age and race and/or ethnicity among females across all U.S counties from 2000 to 2019. The estimates were corrected for misreporting of race and/or ethnicity on death certificates and age-standardized to the 2010 U.S. Census. RESULTS: Age-standardized national breast cancer mortality rates declined between 2000 to 2019, from 33.6 (95% Uncertainty Interval 33.4 to 33.9) to 24.8 (24.6 to 25.0) deaths per 100,000 females. However, there were variations in breast cancer mortality rates across racial and/or ethnic populations at the county level. For instance, 243 of 1,478 counties showed increasing breast cancer mortality rates from 2000 to 2019 among Latina females aged <50 years (absolute increase (median): 0.23 deaths per 100,000; maximum: 1.0). County-level patterns for American Indian/Alaska Native females aged 50 to 74 years showed increasing breast cancer mortality rates across 108 of 474 counties (median: 4.4 per 100,000; max: 17.5). The largest county-level increases were seen among American Indian/Alaska Native (184 of 474 counties; median: 15.2 per 100,000; max: 124.0) and Asian (589 of 667 counties; median: 14.1 per 100,000, max: 41.0) females aged ≥75 years. CONCLUSIONS: Despite a substantial decrease in overall breast cancer mortality rates across all female populations combined in the U.S., there were significant county-level variations in breast cancer mortality rates by race and/or ethnicity.

  PublisherOA PDFDOI

• Data from The Timing, the Treatment, the Question: Comparison of Epidemiologic Approaches to Minimize Immortal Time Bias in Real-World Data Using a Surgical Oncology Example

  2025-11-26

  articleOpen accessSenior author

  &lt;div&gt;AbstractBackground:&lt;p&gt;Studies evaluating the effects of cancer treatments are prone to immortal time bias that, if unaddressed, can lead to treatments appearing more beneficial than they are.&lt;/p&gt;Methods:&lt;p&gt;To demonstrate the impact of immortal time bias, we compared results across several analytic approaches (dichotomous exposure, dichotomous exposure excluding immortal time, time-varying exposure, landmark analysis, clone-censor-weight method), using surgical resection among women with metastatic breast cancer as an example. All adult women diagnosed with incident metastatic breast cancer from 2013–2016 in the National Cancer Database were included. To quantify immortal time bias, we also conducted a simulation study where the “true” relationship between surgical resection and mortality was known.&lt;/p&gt;Results:&lt;p&gt;24,329 women (median age 61, IQR 51–71) were included, and 24% underwent surgical resection. The largest association between resection and mortality was observed when using a dichotomized exposure [HR, 0.54; 95% confidence interval (CI), 0.51–0.57], followed by dichotomous with exclusion of immortal time (HR, 0.62; 95% CI, 0.59–0.65). Results from the time-varying exposure, landmark, and clone-censor-weight method analyses were closer to the null (HR, 0.67–0.84). Results from the plasmode simulation found that the time-varying exposure, landmark, and clone-censor-weight method models all produced unbiased HRs (bias −0.003 to 0.016). Both standard dichotomous exposure (HR, 0.84; bias, −0.177) and dichotomous with exclusion of immortal time (HR, 0.93; bias, −0.074) produced meaningfully biased estimates.&lt;/p&gt;Conclusions:&lt;p&gt;Researchers should use time-varying exposures with a treatment assessment window or the clone-censor-weight method when immortal time is present.&lt;/p&gt;Impact:&lt;p&gt;Using methods that appropriately account for immortal time will improve evidence and decision-making from research using real-world data.&lt;/p&gt;&lt;/div&gt;

  PublisherDOI

• COVID-19 infection and sleep health: findings from the nationally representative COVID-19’s Unequal Racial Burden survey

  Journal of Clinical Sleep Medicine · 2025-03-13

  articleOpen access
  PublisherOA PDFDOI

• Racial and Socioeconomic Disparities in the Surgical Management and Outcomes of Patients with Colorectal Carcinoma

  UNC Libraries · 2025-07-24

  articleOpen access

  INTRODUCTION: Colorectal cancer (CRC) is the second leading cause of cancer mortality in the USA. We aimed to determine racial and socioeconomic disparities in the surgical management and outcomes of patients with CRC in a contemporary, national cohort. METHODS: We performed a retrospective analysis of the National Inpatient Sample for the period 2009-2015. Adult patients diagnosed with CRC and who underwent colorectal resection were included. Multivariable linear and logistic regressions were used to assess the effect of race, insurance type, and household income on patient outcomes. RESULTS: A total of 100,515 patients were included: 72,552 (72%) had elective admissions and 27,963 (28%) underwent laparoscopic surgery. Patients with private insurance and higher household income were consistently more likely to have laparoscopic procedures, compared to other insurance types and income levels, p&thinsp;&lt;&thinsp;0.0001. Black patients, compared to white patients, were more likely to have postoperative complications (OR 1.23, 95% CI, 1.17, 1.29). Patients with Medicare and Medicaid, compared to private insurance, were also more likely to have postoperative complications (OR 1.30, 95% CI, 1.24, 1.37 and OR 1.40, 95% CI, 1.31, 1.50). Patients in low-household-income areas had higher rates of any complication (OR 1.11, 95% CI 1.06, 1.16). CONCLUSIONS: The use of laparoscopic surgery in patients with CRC is strongly influenced by insurance type and household income, with Medicare, Medicaid and low-income patients being less likely to undergo laparoscopic surgery. In addition, black patients, patients with public insurance, and patients with low household income have significant worse surgical outcomes.

  PublisherDOI

• Healthy life expectancy by county, race, and ethnicity in the USA, 2009–19: a systematic analysis of health disparities

  The Lancet Regional Health - Americas · 2025-04-17 · 2 citations

  articleOpen access

  Background: There are substantial disparities in longevity in the USA; however, differences in healthy life expectancy (HALE) remain incompletely understood. We aimed to examine trends and disparities in HALE by race and ethnicity for 3 110 US counties. Methods: We used data from the American Community Survey (2009-19, N = 23.9 m-30.5 m, across indicators), Behavioral Risk Factor Surveillance System (2011-19, N = 1.7 m-3.9 m), Gallup Daily Survey (2009-16, N = 1.8 m-1.9 m); sociodemographic covariates; and disease-specific mortality rates in small-area estimation models to estimate Years Lived with Disability (YLDs) by county, race and ethnicity (American Indian or Alaska Native [AIAN], Asian or Pacific Islander [Asian], Black, Latino or Hispanic [Latino], and White), sex, age, and year (2009-19). We derived HALE using these YLD rates to discount life expectancy. Findings: From 2009 to 2019, HALE declined nationally by 0.3 years (95% uncertainty interval: 0.1-0.5) to 66.2 (62.7-69.4), while life expectancy increased by 0.5 years (0.5-0.5) to 79.1 (79.1-79.1). The Asian population had the highest HALE (72.3 [68.5-75.5] in 2019), followed by the Latino (68.5 [64.7-71.8]), White (65.9 [62.3-69.1]), Black (63.4 [60.1-66.3]), and AIAN populations (60.7 [57.0-64.1]). The Latino population had the longest absolute duration in poor health (13.8 years [10.4-17.6] in 2019) whereas the AIAN population had the longest proportion of life in poor health (17.3% [13.0-22.2]). From 2009 to 2019, HALE declined for the AIAN (by 1.4 years [1.0-1.8]) and White (by 0.6 years [0.4-0.8]) populations and the proportion of life in poor health increased for all populations. At the county level, HALE declined in 91.3% of counties (2 812 of 3 079; 65.6% statistically significant) from 2000 to 2019 and ranged from 55.1 to 76.2 years in 2019. Racial and ethnic disparities at the county level were broadly similar to national patterns, but with some exceptions. Interpretation: Disparities in HALE in the USA are large, and HALE has worsened for many populations in recent years. The expanding duration and proportion of life spent in poor health could indicate an increasing need for health services. Funding: Intramural Research Program, National Institute on Minority Health and Health Disparities, US National Institutes of Health (contract #75N94023C00004). Intramural Research Program, National Institute on Minority Health and Health Disparities; National Heart, Lung, and Blood Institute; Intramural Research Program, National Cancer Institute; National Institute on Aging; National Institute of Arthritis and Musculoskeletal and Skin Diseases; Office of Disease Prevention; and Office of Behavioral and Social Sciences Research, US National Institutes of Health (contract #75N94019C00016).

  PublisherOA PDFDOI

• Life expectancy by county and educational attainment in the USA, 2000–19: an observational analysis

  The Lancet Public Health · 2025-01-23 · 9 citations

  articleOpen access

  BACKGROUND: Educational disparities in life expectancy in the USA have been documented nationally but have not been comprehensively explored at the county level. Such geographical granularity is necessary for determining how these disparities vary across the country, thus highlighting the populations that could benefit most from increased access to educational support. We aim to estimate life expectancy at age 25 years for US counties from 2000 to 2019 for four educational attainment populations: less than high school, high-school graduate (including certificate of high school equivalency or other alternative credentials), some college (including associate degrees and incomplete college), and college graduate (including graduate and professional degrees). METHODS: In this observational analysis, we estimated age-specific mortality by educational attainment, county, sex, age, and year using validated small-area estimation models, and then used standard life table techniques to estimate life expectancy at age 25 years using deaths data from the US National Vital Statistics System and population data from the 2000 decennial census, American Community Survey, and National Center for Health Statistics between Jan 1, 2000, and Dec 31, 2019. Estimates were adjusted for misclassification of educational attainment on death certificates and format changes to how education is captured on death certificates. We masked (ie, did not display) estimates for counties and educational attainment populations with a mean annual population of less than 1000. FINDINGS: Nationally, in all years there was a clear educational gradient in life expectancy at age 25 years where those with higher levels of education had higher life expectancy: individuals who had completed a college degree had higher life expectancy compared with those who had completed some college education (by 0·3 to 2·0 years over the study period), those who had completed some college had higher life expectancy than the high-school graduate population (by 4·1 to 4·9 years over the study period), and those who had graduated high school had higher life expectancy than those with less than a high-school education (by 3·4 to 5·1 years over the study period). From 2000 to 2019, life expectancy increased by 2·5 years (95% uncertainty interval 2·4 to 2·6) for the college graduate population, 0·7 years (0·6 to 0·8) for the population who had completed some college, and 0·3 years (0·3 to 0·4) for the high-school graduate population; there was no net change for those with less than a high-school education (0·0 years [-0·1 to 0·1]). In every educational attainment population, life expectancy increased by more from 2000 to 2010, with diminishing gains or even declines from 2010 to 2019. Life expectancy varied at the county level; eg, in 2019, the IQR for the population with less than a high-school education was 67·4 to 72·1 years, whereas for the college graduate population it was 82·3 to 84·6 years among counties with unmasked estimates. The college graduate population had higher life expectancy than those who had completed some college in 1937 (81·1%) of 2389 counties (47·1% statistically significant), which in turn had higher life expectancy than the high-school graduate population in 2726 (97·7%) of 2791 counties (87·0% statistically significant), which in turn had higher life expectancy than the population with less than a high-school education in 2356 (95·9%) of 2456 counties (91·6%). Over the study period, the gap in life expectancy between the college graduate population and those with less than a high-school education grew in 2594 (84·8%) of 3060 counties. INTERPRETATION: Educational disparities in life expectancy are large, widespread, and increasing, both nationally and in most counties throughout the USA. Further research is needed to determine how both more equitable access to higher education and efforts to mitigate barriers to good health facing people with lower levels of education might result in better health and longer lives. FUNDING: Intramural Research Program, National Institute on Minority Health and Health Disparities; National Heart, Lung, and Blood Institute; Intramural Research Program, National Cancer Institute; National Institute on Aging; National Institute of Arthritis and Musculoskeletal and Skin Diseases; Office of Disease Prevention; and Office of Behavioral and Social Sciences Research, US National Institutes of Health.

  PublisherDOI

• Does acral lentiginous melanoma subtype account for differences in patterns of care in Black patients?

  UNC Libraries · 2025-07-16

  articleOpen access
  PublisherDOI

• Pathologic complete response and survival after neoadjuvant chemotherapy in cT1-T2/N0 HER2+ breast cancer

  UNC Libraries · 2025-07-19

  articleOpen access
  PublisherDOI

• Trends in the management and outcomes of esophageal perforations among racial-ethnic groups

  UNC Libraries · 2025-04-01

  articleOpen access

  Background: Esophageal perforation (EP) is a life-threatening emergency requiring emergent surgical intervention. Little is known about potential racial-ethnic disparities among patients with EP. Methods: Hospitalizations of adult (&ge;18 years old) patients admitted with a diagnosis of EP were identified in the 2000-2017 National Inpatient Sample (NIS). Multivariable Cox proportional hazards regression was used to estimate the association between race-ethnicity and inpatient mortality. Inpatient complications were assessed using multivariable logistic regression. Results: There were an estimated 36,531 EP hospitalizations from 2000-2017. One quarter of hospitalizations were racial or ethnic minorities. Non-Hispanic (NH) White patients were, on average, older (median age 58 vs. 41 and 47 years, respectively, P&lt;0.0001). The rate of EP admissions, per 1,000,000 the United States (US) adults, significantly increased among all groups over time. In-hospital mortality decreased for both NH White and NH Black patients (10.2% to 4.6% and 8.3% to 4.9%, respectively, P&lt;0.0001) but increased for Hispanic patients and patients of other races (2.9% to 4.7% and 3.4% to 6.9%, P&lt;0.0001). NH Black patients were more likely to have sepsis during their hospital course [odds ratio (OR) =1.34; 95% confidence interval (CI): 1.08 to 1.66], and patients of other races (OR =1.44; 95% CI: 1.01 to 2.07) were more likely to have pneumonia. Similar rates of surgical intervention were seen among all racial-ethic groups. After adjustment, inpatient mortality did not differ among racial-ethnic groups. Conclusions: Rates of EP admissions have increased for all racial-ethnic groups since 2000. Despite similar incidences of inpatient mortality across groups, NH Black and other race patients were more likely to experience postoperative complications, suggesting potential racial-ethnic disparities in quality or access to care.

  PublisherDOI

• Patient-Clinician Sex and Race and/or Ethnicity Concordance and Adherence to Preventive Services Guidelines: MEPS 2018–2020

  Journal of General Internal Medicine · 2025-06-03 · 2 citations

  articleOpen accessSenior author

  BACKGROUND: Patient-clinician sex, racial, and ethnic concordance have been shown to improve healthcare utilization, but the impact of each on adherence to preventive services guidelines among specific populations remains unclear. OBJECTIVE: To estimate the association between patient-clinician sex and racial and/or ethnic concordance and adherence to preventive services guidelines. DESIGN: Cross-sectional study using nationally representative data from the Medical Expenditure Panel Survey (2018, 2020). PARTICIPANTS: Adults ≥ 18 years old who reported having a usual healthcare clinician. Adults who identified as multiracial, identified their clinician as being multiracial, or who did not report clinician sex, race, or ethnicity were excluded. MAIN MEASURES: Adherence to preventive services guidelines for influenza, pneumococcal, and shingles vaccines; breast, cervical, and colorectal cancer screening; and blood pressure and cholesterol screening. Predicted marginal prevalences and prevalence ratios were estimated using multivariable logistic regression, adjusting for sociodemographics, chronic conditions, and self-reported health status. KEY RESULTS: Females were less likely to report sex concordance compared to males (52.5% vs. 69.8%, p < 0.01). Among females, sex concordance increased influenza (PR = 1.08, 95% CI = 1.04-1.12), pneumococcal (PR = 1.06, 95% CI = 1.02-1.11), and shingles (PR = 1.09, 95% CI = 1.01-1.17) vaccination, as well as breast (PR = 1.06, 95% CI = 1.01-1.10), cervical (PR = 1.09, 95% CI = 1.05-1.13), and colorectal (PR = 1.07, 95% CI = 1.03-1.10) cancer screening, but not among males. Racial and/or ethnic concordance was low among American Indian and Alaska Native, Black, Latino, and Native Hawaiian and Pacific Islander patients (< 25%) and was not associated with adherence in preventive services. CONCLUSIONS: Females with female clinicians are more likely to adhere to preventive services guidelines. Racial and/or ethnic concordance was not associated with adherence to preventive services guidelines, but racial and/or ethnic concordance was low among non-White patients. Sex and racial and/or ethnic concordance may be a powerful tool for increasing preventive services utilization, but increased racial and/or ethnic concordance is needed to reach more definitive conclusions.

  PublisherOA PDFDOI

Frequent coauthors

• Anna María Nápoles

  National Institutes of Health

  89 shared

• Kristalyn Gallagher

  University of North Carolina at Chapel Hill

  67 shared

• Apoorve Nayyar

  University of Iowa Hospitals and Clinics

  55 shared

• Kandace P. McGuire

  Virginia Commonwealth University

  54 shared

• Anita L. Stewart

  45 shared

• Sameer Arora

  University of North Carolina at Chapel Hill

  43 shared

• Michelle R. Brownstein

  East Carolina University

  43 shared

• David W. Ollila

  University of North Carolina at Chapel Hill

  43 shared

Education

• PhD, Epidemiology

  University of North Carolina at Chapel Hill

  2019

• MSPH, Epidemiology

  Emory University School of Public Health

  2014

• BS, Psychology

  University of Maryland Baltimore County

  2010

Awards & honors

• NIH Director’s Award – Emerging Leader, 2023
• NIMHD William G. Coleman Minority Health and Health Disparit…
• NIMHD Merit Award for Scientific Innovation, 2021
• William Rutala scholarship, Society for Healthcare Epidemiol…
• Travel scholarship, International Society for Pharmacoepidem…