Scholars@Duke
Nikki Freeman

Nikki Freeman

Assistant Professor of Biostatistics & Bioinformatics
Biostatistics & Bioinformatics, Division of Biostatistics
nikki.freeman@duke.edu
300 W. Morgan Street, Durham, NC 27701

Selected Publications

Use of machine learning to identify characteristics associated with severe hypoglycemia in older adults with type 1 diabetes: a post-hoc analysis of a case-control study.

Journal Article BMJ Open Diabetes Res Care · February 27, 2024 INTRODUCTION: Severe hypoglycemia (SH) in older adults (OAs) with type 1 diabetes is associated with profound morbidity and mortality, yet its etiology can be complex and multifactorial. Enhanced tools to identify OAs who are at high risk for SH are needed ... Full text Link to item Cite

Individualized treatment rule characterization via a value function surrogate.

Journal Article Biometrics · January 29, 2024 Precision medicine is a promising framework for generating evidence to improve health and health care. Yet, a gap persists between the ever-growing number of statistical precision medicine strategies for evidence generation and implementation in real-world ... Full text Link to item Cite

Assessing risk of bias in the meta-analysis of round 1 of the Health Care Innovation Awards.

Journal Article Syst Rev · January 22, 2024 BACKGROUND: Systematic reviews of observational studies can be affected by biases that lead to under- or over-estimates of true intervention effects. Several tools have been reported in the literature that attempt to characterize potential bias. Our object ... Full text Link to item Cite

Balancing evidence-based care with patient-centered individualized care.

Conference J Vasc Surg Venous Lymphat Disord · November 2023 Weak evidence, when manifested in clinical guidelines, can translate into biased vascular care. In vascular surgery, we have few randomized controlled trials with appropriate representation of females and persons of color, so generalizability of trial resu ... Full text Link to item Cite

Individualized interventions and precision health: Lessons learned from a systematic review and implications for analytics-driven geriatric research.

Journal Article J Am Geriatr Soc · February 2023 Older adults are characterized by profound clinical heterogeneity. When designing and delivering interventions, there exist multiple approaches to account for heterogeneity. We present the results of a systematic review of data-driven, personalized interve ... Full text Link to item Cite

Differential impact of missed initial wound clinic visit on 6-month wound healing by race/ethnicity among patients with chronic limb-threatening ischemia.

Journal Article Wound Repair Regen · 2023 Chronic limb-threatening ischemia (CLTI) is associated with significant morbidity, including major limb amputation, and mortality. Healing ischemic wounds is necessary to optimise vascular outcomes and can be facilitated by dedicated appointments at a woun ... Full text Link to item Cite

Central concepts for randomized controlled trials and other emerging trial designs.

Journal Article Semin Vasc Surg · December 2022 Randomized controlled trials (RCTs) are widely considered to provide the highest-quality evidence for the comparative efficacy and safety of competing clinical strategies. The strength of using RCTs for causal inference is derived from random treatment ass ... Full text Link to item Cite

Analysis of a Machine Learning-Based Risk Stratification Scheme for Chronic Limb-Threatening Ischemia.

Journal Article JAMA Netw Open · March 1, 2022 IMPORTANCE: Valid risk stratification schemes are key to performing comparative effectiveness research; however, for chronic limb-threatening ischemia (CLTI), risk stratification schemes have limited efficacy. Improved, accurate, comprehensive, and reprodu ... Full text Link to item Cite

Mapping mental health inequalities: The intersecting effects of gender, race, class, and ethnicity on ADHD diagnosis.

Journal Article Sociol Health Illn · March 2022 While the effects of social stratification by gender, race, class, and ethnicity on health inequalities are well-documented, our understanding of the intersecting consequences of these social dimensions on diagnosis remains limited. This is particularly th ... Full text Link to item Cite

The Society for Vascular Surgery Objective Performance Goals for Critical Limb Ischemia are attainable in select patients with ischemic wounds managed with wound care alone.

Journal Article Ann Vasc Surg · January 2022 BACKGROUND: To set therapeutic benchmarks, in 2009 the Society for Vascular Surgery defined objective performance goals (OPG) for treatment of patients with chronic limb threatening ischemia (CLTI) with either open surgical bypass or endovascular intervent ... Full text Link to item Cite

Limiting adverse birth outcomes in resource-limited settings (LABOR): protocol of a prospective intrapartum cohort study.

Journal Article Gates Open Res · 2022 Background: Each year, nearly 300,000 women and 5 million fetuses or neonates die during childbirth or shortly thereafter, a burden concentrated disproportionately in low- and middle-income countries. Identifying women and their fetuses at risk for intrapa ... Full text Link to item Cite

Enhanced recovery after thoracic surgery: Systematic review and meta-analysis.

Journal Article JTCVS Open · September 2021 ERATS decreased length of stay, postoperative complications, and readmission. ... Full text Link to item Cite

Beyond Two Cultures: Cultural Infrastructure for Data-driven Decision Support.

Journal Article Obs Stud · July 2021 In the twenty years since Dr. Leo Breiman's incendiary paper Statistical Modeling: The Two Cultures was first published, algorithmic modeling techniques have gone from controversial to commonplace in the statistical community. While the widespread adoption ... Full text Link to item Cite

Precision Medicine Enables More TNM-Like Staging in Patients With Chronic Limb Threatening Ischemia.

Journal Article Front Cardiovasc Med · 2021 Introduction: In cancer, there are survival-based staging systems and tailored, stage-based treatments. There is little personalized treatment in vascular disease. The 2019 Global Vascular Guidelines on the Management of CLTI proposed successful treatment ... Full text Link to item Cite

The future of precision health is data-driven decision support

Journal Article Statistical Analysis and Data Mining · December 1, 2020 In the applied sciences, the ultimate goal is not just to acquire knowledge but to turn knowledge into action. The next wave for data disciplines may be experimental designs and analytical methods for closing the gap between the “real-world” situations fac ... Full text Cite

Comment: Models as Approximations.

Journal Article Stat Sci · November 2019 Full text Link to item Cite

Making Evidence Actionable: Interactive Dashboards, Bayes, and Health Care Innovation.

Journal Article EGEMS (Wash DC) · August 5, 2019 The results of many large-scale federal or multi-site evaluations are typically compiled into long reports which end up sitting on policymaker's shelves. Moreover, the information policymakers need from these reports is often buried in the report, may not ... Full text Link to item Cite

A systematic review of enhanced recovery after surgery for vascular operations.

Journal Article J Vasc Surg · August 2019 BACKGROUND: Patients undergoing vascular operations face high rates of intraoperative and postoperative complications and delayed return to baseline. Enhanced recovery after surgery (ERAS), with its aim of delivering high-quality perioperative care and acc ... Full text Link to item Cite

Early major complications after bariatric surgery in the USA, 2003-2014: a systematic review and meta-analysis.

Journal Article Obes Rev · April 2018 The effectiveness of bariatric surgery has been well-studied. However, complications after bariatric surgery have been understudied. This review assesses <30-d major complications associated with bariatric procedures, including anastomotic leak, myocardial ... Full text Link to item Cite

Use of machine learning to identify characteristics associated with severe hypoglycemia in older adults with type 1 diabetes: a post-hoc analysis of a case-control study.

Journal Article BMJ Open Diabetes Res Care · February 27, 2024 INTRODUCTION: Severe hypoglycemia (SH) in older adults (OAs) with type 1 diabetes is associated with profound morbidity and mortality, yet its etiology can be complex and multifactorial. Enhanced tools to identify OAs who are at high risk for SH are needed ... Full text Link to item Cite

Individualized treatment rule characterization via a value function surrogate.

Journal Article Biometrics · January 29, 2024 Precision medicine is a promising framework for generating evidence to improve health and health care. Yet, a gap persists between the ever-growing number of statistical precision medicine strategies for evidence generation and implementation in real-world ... Full text Link to item Cite

Assessing risk of bias in the meta-analysis of round 1 of the Health Care Innovation Awards.

Journal Article Syst Rev · January 22, 2024 BACKGROUND: Systematic reviews of observational studies can be affected by biases that lead to under- or over-estimates of true intervention effects. Several tools have been reported in the literature that attempt to characterize potential bias. Our object ... Full text Link to item Cite

Balancing evidence-based care with patient-centered individualized care.

Conference J Vasc Surg Venous Lymphat Disord · November 2023 Weak evidence, when manifested in clinical guidelines, can translate into biased vascular care. In vascular surgery, we have few randomized controlled trials with appropriate representation of females and persons of color, so generalizability of trial resu ... Full text Link to item Cite

Individualized interventions and precision health: Lessons learned from a systematic review and implications for analytics-driven geriatric research.

Journal Article J Am Geriatr Soc · February 2023 Older adults are characterized by profound clinical heterogeneity. When designing and delivering interventions, there exist multiple approaches to account for heterogeneity. We present the results of a systematic review of data-driven, personalized interve ... Full text Link to item Cite

Differential impact of missed initial wound clinic visit on 6-month wound healing by race/ethnicity among patients with chronic limb-threatening ischemia.

Journal Article Wound Repair Regen · 2023 Chronic limb-threatening ischemia (CLTI) is associated with significant morbidity, including major limb amputation, and mortality. Healing ischemic wounds is necessary to optimise vascular outcomes and can be facilitated by dedicated appointments at a woun ... Full text Link to item Cite

Central concepts for randomized controlled trials and other emerging trial designs.

Journal Article Semin Vasc Surg · December 2022 Randomized controlled trials (RCTs) are widely considered to provide the highest-quality evidence for the comparative efficacy and safety of competing clinical strategies. The strength of using RCTs for causal inference is derived from random treatment ass ... Full text Link to item Cite

Analysis of a Machine Learning-Based Risk Stratification Scheme for Chronic Limb-Threatening Ischemia.

Journal Article JAMA Netw Open · March 1, 2022 IMPORTANCE: Valid risk stratification schemes are key to performing comparative effectiveness research; however, for chronic limb-threatening ischemia (CLTI), risk stratification schemes have limited efficacy. Improved, accurate, comprehensive, and reprodu ... Full text Link to item Cite

Mapping mental health inequalities: The intersecting effects of gender, race, class, and ethnicity on ADHD diagnosis.

Journal Article Sociol Health Illn · March 2022 While the effects of social stratification by gender, race, class, and ethnicity on health inequalities are well-documented, our understanding of the intersecting consequences of these social dimensions on diagnosis remains limited. This is particularly th ... Full text Link to item Cite

The Society for Vascular Surgery Objective Performance Goals for Critical Limb Ischemia are attainable in select patients with ischemic wounds managed with wound care alone.

Journal Article Ann Vasc Surg · January 2022 BACKGROUND: To set therapeutic benchmarks, in 2009 the Society for Vascular Surgery defined objective performance goals (OPG) for treatment of patients with chronic limb threatening ischemia (CLTI) with either open surgical bypass or endovascular intervent ... Full text Link to item Cite

Limiting adverse birth outcomes in resource-limited settings (LABOR): protocol of a prospective intrapartum cohort study.

Journal Article Gates Open Res · 2022 Background: Each year, nearly 300,000 women and 5 million fetuses or neonates die during childbirth or shortly thereafter, a burden concentrated disproportionately in low- and middle-income countries. Identifying women and their fetuses at risk for intrapa ... Full text Link to item Cite

Enhanced recovery after thoracic surgery: Systematic review and meta-analysis.

Journal Article JTCVS Open · September 2021 ERATS decreased length of stay, postoperative complications, and readmission. ... Full text Link to item Cite

Beyond Two Cultures: Cultural Infrastructure for Data-driven Decision Support.

Journal Article Obs Stud · July 2021 In the twenty years since Dr. Leo Breiman's incendiary paper Statistical Modeling: The Two Cultures was first published, algorithmic modeling techniques have gone from controversial to commonplace in the statistical community. While the widespread adoption ... Full text Link to item Cite

Precision Medicine Enables More TNM-Like Staging in Patients With Chronic Limb Threatening Ischemia.

Journal Article Front Cardiovasc Med · 2021 Introduction: In cancer, there are survival-based staging systems and tailored, stage-based treatments. There is little personalized treatment in vascular disease. The 2019 Global Vascular Guidelines on the Management of CLTI proposed successful treatment ... Full text Link to item Cite

The future of precision health is data-driven decision support

Journal Article Statistical Analysis and Data Mining · December 1, 2020 In the applied sciences, the ultimate goal is not just to acquire knowledge but to turn knowledge into action. The next wave for data disciplines may be experimental designs and analytical methods for closing the gap between the “real-world” situations fac ... Full text Cite

Comment: Models as Approximations.

Journal Article Stat Sci · November 2019 Full text Link to item Cite

Making Evidence Actionable: Interactive Dashboards, Bayes, and Health Care Innovation.

Journal Article EGEMS (Wash DC) · August 5, 2019 The results of many large-scale federal or multi-site evaluations are typically compiled into long reports which end up sitting on policymaker's shelves. Moreover, the information policymakers need from these reports is often buried in the report, may not ... Full text Link to item Cite

A systematic review of enhanced recovery after surgery for vascular operations.

Journal Article J Vasc Surg · August 2019 BACKGROUND: Patients undergoing vascular operations face high rates of intraoperative and postoperative complications and delayed return to baseline. Enhanced recovery after surgery (ERAS), with its aim of delivering high-quality perioperative care and acc ... Full text Link to item Cite

Early major complications after bariatric surgery in the USA, 2003-2014: a systematic review and meta-analysis.

Journal Article Obes Rev · April 2018 The effectiveness of bariatric surgery has been well-studied. However, complications after bariatric surgery have been understudied. This review assesses <30-d major complications associated with bariatric procedures, including anastomotic leak, myocardial ... Full text Link to item Cite

Impact Of Health Care Delivery System Innovations On Total Cost Of Care.

Journal Article Health Aff (Millwood) · March 1, 2017 Using delivery system innovations to advance health care reform continues to be of widespread interest. However, it is difficult to generalize about the success of specific types of innovations, since they have been examined in only a few studies. To gain ... Full text Link to item Cite

Profile of Justice-Involved Marijuana and Other Substance Users: Demographics, Health and Health Care, Family, and Justice System Experiences.

Journal Article Subst Abuse · 2017 Substance users are more likely to have co-occurring health problems, and this pattern is intensified among those involved with the criminal justice system. Interview data for 1977 incarcerated men in 5 states from the Multi-site Family Study on Incarcerat ... Full text Link to item Cite