Blog

This week's Spotlight features one of our newer staff biostatisticians, Ahra Kim.  Learn how this Southern California native ventured East to Nashville for a great opportunity in research and is now learning to brave the winters, all while providing statistical support to her collaborators here at Vanderbilt.

Tell us about the research you are involved in.
I am involved with three collaborations here at Vanderbilt. Half of my time is spent working on projects with the Caribbean, Central and South America network (CCASAnet) for HIV epidemiology. It consists of HIV clinical sites from seven countries in Latin America, and is also a member of a larger consortium, International Epidemiologic Databases to Evaluate AIDS (IeDEA). In one study, we are comparing outcomes such as mortality, retention in care, and timing of antiretroviral therapy initiation in HIV infected adults with and without tuberculosis. We have recently submitted several abstracts to a conference and are currently working on additional analyses for manuscripts.

My two other collaborations are with the Department of Psychiatry and Center for Biomedical Ethics. For one project in Psychiatry, we are interested in assessing how catatonia and delirium affect survival in critically-ill patients. For Biomedical Ethics, we have been trying to better understand characteristics of patients needing ethical consults for controversial topics like organ donation or treatment decision making, as well as practice patterns of clinicians when it comes to these issues. I am grateful to be working on such a wide range of interesting projects.

What was your draw to statistics and/or Vanderbilt? 
I was drawn to statistics in a non-traditional way since I have a social science background. I enjoyed doing research, but many of my classes as an undergraduate involved secondary research and I wanted to do something more hands-on. I was fascinated when I took a course in biostatistics, which was my first exposure to learning R programming. This encouraged me to pursue a master’s degree in biostatistics. Joining the Department at Vanderbilt was an amazing opportunity for me as a new graduate, so I relocated from California.

What lessons have you learned from being a biostatistician?
Though I haven’t been a biostatistician for very long now, I’ve learned that being organized and transparent is key. Sometimes projects pause and resume months or even years later, so it’s helpful to clearly document everything and practice reproducibility to avoid confusion and save time in the long run.

What makes Vanderbilt special in your experiences of collaborating with others?
The collaboration opportunities here have been wonderful. Everybody has been very kind and respectful, and view statisticians as valuable team members. I also appreciate the diverse resources and how there are so many experts in various fields that you can learn from, especially if you encounter a difficult problem in an area you may not be familiar with.

Tell us about your life outside of Vanderbilt. Do you have a significant other? What about your hobbies?
I have been engaged to my fiancé for almost a year now and will be getting married next spring. We both moved here from California. Outside of work, I enjoy a variety of hobbies including hiking, playing tennis, and practicing yoga. I also like to see live music performances, visit cool galleries or exhibits, and occasionally attend sporting events.

Finally, what is something about you that most people at Vanderbilt still don't know about you?
Prior to moving to Nashville, I lived in an inland region of Southern California (Inland Empire) where summer temperatures can reach highs of 116 degrees Fahrenheit. Winters are usually mild with highs in the 60s. Coming to Nashville, I was shocked to see temperatures drop to single digits last winter. Though I’ve been here for a year and half now, I still haven’t acclimated fully to the cold!

This week's spotlight features one of our amazing staff biostatisticians, Samuel Nwosu.  Read on to learn more about his work and contributions to medical research through biostatistics . . . 

What is your research focus and what have been the major findings so far in your research? 
My main research collaboration has been working with the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) clinical trial group.  This has been a 6 year ongoing NIH grant funded study, with a primary goal of determining whether an invasive (INV) strategy of routine early cardiac catheterization will reduce the incidence of major adverse cardiovascular death as compared to an initial conservative (CON) medical therapy approach.  The study spans across 38 countries with over 300 sites enrolling patients.  This is a great team to be part of, there are seven principle collaborators and 16 collaborating research institutes, all having vast knowledge and experience in cardiovascular research. 

The study is scheduled to be completed towards the end of 2019 and we are currently working to finalize the main manuscripts.  In July of this past year, while outlining the methods and procedures of the trial, our study group did publish the ISCHEMIA Design Paper in the American Heart Journal (AHJ) which was a great accomplishment.  

Our group is also working on a ancillary ISCHEMIA trial called the Chronic Kidney Disease (CKD) trial.  The primary objective of this trial is to determine whether an invasive strategy of cardiac catheterization will reduce the composite endpoint of death or nonfatal myocardial infarction in patients with stable ischemic heart disease and advanced chronic kidney disease.  This study is also a multinational trial including 30 countries and over 100 sites.
With ischemia being one of the leading causes in heart disease, its great knowing that this research can change how they diagnose and treat this condition as we move into the future.


What was your draw to statistics and/or Vanderbilt?
It was almost serendipitous how I got into the field of biostatistics.  I have somewhat always had an affinity for math and how it relates to everyday life.  I graduated with an undergraduate degree in mathematics, uncertain which career field I should pursue with my degree.  I researched different fields from accounting to economics, then by chance one of my undergraduate professors asked me if I liked statistics and suggested I look into the field of biostatistics.  As I researched the more about biostatistics I saw how I could bridge my background in mathematics with statistics and apply it to the field of health research.  Upon finishing my last semester in graduate school, my advisor forwarded me the job opening for a biostatistician II position within Vanderbilt's biostatistics department, I applied and I was able to start my career as a biostatistician.


What makes Vanderbilt special in your experiences of collaborating with others?
What I enjoy about my job is the opportunity to work with so many talented people and the ability to be involved in cutting edge research.  I've been able to work on a variety of different collaborations from PTSD research to multinational clinical trials.  I like the fact that knowing the research I am involved with can enrich the scientific world and benefit people at the same time.  Plus, it is also gratifying that I work in a department that fosters growth and high importance on continuing education.  I've been able to grow as a biostatistician due to working in such a great environment.


Tell us about your life outside of Vanderbilt.
I am married to Brionni Nwosu, a professor at the Relay Graduate School of Education.  We have two beautiful girls named Kanaya (4 years old) and Kalia (15 months old) who keep our lives filled with joy and excitement.  As a family we enjoy spending time playing at the park, visiting the animals at the zoo, or viewing all the sea and water creatures at the aquarium.


Finally, what is something about you that most people at Vanderbilt still don't know about you?
I enjoy the occasional adventurous/extreme activity from time to time- whether it is zip lining, scuba diving, bungee jumping, high speed Go-Karting, or off-roading on dune buggies, I'm game.
 

We have a new staff member onboard!  Elizabeth McNeer recently joined our group as a Biostatistician II.  Read on to learn more about her studies and interests here:

What is your area of focus?
I’m just starting out as a biostatistician, so I don’t have much research experience yet. My master’s thesis work under the direction of Dr. Dandan Liu focused on evaluating the impact of various chart review strategies using electronic health record data in the context of risk prediction modeling. I currently work with researchers in the Vanderbilt Center for Child Health Policy where I’m involved with various projects that focus on improving the well-being of children. I have ongoing projects dealing with topics such as hepatitis C testing in infants and mechanical ventilation in the neonatal intensive care unit.

What was your draw to statistics and/or Vanderbilt? What has served as the pathway to your position?
As an undergraduate, I majored in math and biology, so I wanted to find a career that would combine both of my interests. I also had an interest in the medical field, so the biology courses that I chose to take were the same courses that the pre-med majors took. During the summer after my junior year of college, I attended a Summer Institute for Training in Biostatistics program at Emory University. After this program, I knew that I wanted to pursue a graduate degree in biostatistics. I came to Vanderbilt in 2016 after graduating from Mississippi College, and I earned an MS in Biostatistics in the summer of 2018. Because of my interest in the medical field, I knew that I wanted to work at a medical center like Vanderbilt, so I’m excited to now be working in the same department where I spent two years as a student!

What makes Vanderbilt special in your experiences of collaborating with others?
I’ve found that my collaborators treat me like a valuable part of the group and want me involved in the entire project, not just the parts involving statistical analysis. My collaborators value the work that I do, which makes coming to work enjoyable. I’ve also been encouraged to continually learn and apply new skills to the projects that I work on.

Tell us about your life outside of Vanderbilt.
After being in school most of my life, I’m really enjoying not having constant homework and studying to do! I enjoy reading, watching Netflix, playing board games, and hiking every once in a while. I attend The Church at Avenue South, and I also tutor math on the weekends. Also, I very much enjoy Jeni’s ice cream.

Finally, what is something that most people at Vanderbilt still don’t know about you?
Long before I took my first statistics class or knew I would have a career in statistics, my dad bought me a baseball score book and showed me how to keep baseball statistics. In elementary and middle school, I would keep stats for my brother’s Little League teams just for fun. Keeping stats helped me understand and appreciate baseball, and I still enjoy going to an occasional baseball game.

Next up in the spotlight is one of our Senior Project Managers in the Center for Quantitative Sciences, Mr. David Biagi .  Learn more about his role on the team and how he may find favor with a four-legged creature in the coming year . . .

Tell us about your group and role within the CQS IT team.
Our team in the Collaborative Studies Coordinating Center provides database and development support to a wide range of research projects. Our goal is to remove technological barriers for our collaborators. Currently we maintain a wide variety of projects for international research groups, including virtual bio-repositories, clinical trial management systems, and outcome aggregation systems. We hope to continue to enable science-at-scale by helping researchers pool their data, resources, and efforts.

What drew you to Vanderbilt and what has been your experience working in a collaborative environment such as this?
I was attracted to Vanderbilt by the personal recommendation of several colleagues. That trust was not misplaced, as it has been a great place to build a career over the last ten years. I have always felt like my input was valued and appreciated the way I have been enabled to pursue and achieve goals I've suggested in support of the department's efforts.

Tell us about your life outside of Vanderbilt. Do you have a significant other? Children? Pets? 
I'm married to my high school sweetheart and we have four daughters ages six months to seven years old. There's a long standing family debate raging over whether or not we should get a dog. I stand alone in opposition and I plan to lose this debate sometime next year.

Meet one of our newest faculty members, Dr. Simon Vandekar, an Assistant Professor in the Department of Biostatistics.  He is a great addition to our group and it's a pleasure to get to know him.

What are your research interests and what is the focus of your research? What have been the major findings so far?  
My statistical research develops inference procedures for high-dimensional data with a particular focus on neuroimaging data. This research has been published in Biostatistics, Neuroimage, and JASA. My collaborative research studies how the brain changes through development and how it is affected in psychiatric disorders. This work has been published in the Journal of Neuroscience, Nature Communications, and Science. My research has relied on family-wise error rate, spatial extent inference, and semiparametric procedures and I would like to begin to develop nonparametric procedures that control the false discovery rate. I am also interested in high-dimensional measures of replicability and the stability of findings across varying preprocessing parameters.

Tell us about any honors you have received, awards you have won or any significant publications you've had.
I was awarded the Saul Winegrad Oustanding Dissertation in my graduate group when I graduated in May 2018. My most recent first author publications were in JASA, Biostatistics, and the Journal of Cerebral Blood Flow and Metabolism.

What was your draw to statistics and what are some of your goals?
I realized I loved statistics after working in a neuroimaging lab after graduation with a BS in psychology. The goal of my research is to develop statistical tools that can be immediately applied to real world problems. I am most interested in semiparametric methods to do this.

Can you share the status of any of your past students?  What is your philosophy about teaching or research?
I haven’t mentored any students, but I look forward to the opportunity! I personally learn mathematical or statistical tools best when I use them to solve problems in my research. I think statistical methods should try to make realistic assumptions about the data and that the analysis approach should be determined by particular questions or hypotheses.

What makes Vanderbilt special in your experiences of collaborating with others? What are your thoughts on controversial statistical topics such as adjusting the p-value for multiple comparison, the choice between Bayesian, likelihood, or frequentists, ethical issues, etc.?
The collaborators I’ve worked with here seem extremely focused on the wellbeing of their patients, which makes working with them more rewarding. My work is in multiple comparisons adjustment and I see it as a way for understanding the amount of bias induced by looking at hundreds of thousands of variables, but I don’t think that we should use hard thresholds to decide about the unknown state of the world. Two studies that presents results with and without adjustment are equally valid, but the first provides more evidence against the null hypothesis. I am interested in learning more about semiparametric likelihood and Bayesian methods. I like the probabilistic statements the Bayesian philosophy affords but have an aversion to priors or heavily parametric models because I’m not sure how assumption violations affect the bias and interpretation.

Tell us about your life outside of Vanderbilt. Do you have a significant other? What about your hobbies? 
My spouse currently lives in Houston with our two dogs (a dachshund and a basset-lab mix), where she is doing an internship, but she will get to move here soon! I like hiking, camping, running and visiting the many delicious breweries we have in Nashville. I also like foraging for mushrooms.

Finally, what is something about you that most people at Vanderbilt still don't know about you? (Until now, of course!)
My wife and I dabble in extreme sports. My favorite was hang gliding, but we also tried sky diving and go scuba diving not too infrequently.

This week we are excited to feature Quanhu "Tiger" Sheng who is one of our Research Assistant Professors in the Department of Biostatistics and also the Technical Associate Director of VANGARD.  Learn more about his work and interests here at Vanderbilt as you read on below:

What is your area of interest and what have been your findings? What are the next steps for your research?
I like coding and I always believe the algorithm development and/or paper should not be the end of our bioinformatics/biostatistics research, therefore I  focus on developing algorithms and implement software to help the lab, the collaborator and the research community.

For example, I have worked on TurboRawToMGF, BuildSummary and ProteomicsTools for proteomics research, NGFPERL, GLMVC and TIGER for next generation sequencing analysis. Almost all of those findings have come from my very close collaborations with various wet lab researchers. The manuscripts produced have been published in journals such as  Rapid Commun Mass Spectrom, J Proteome Res, Genomics and Journal of Extracellular Vesicles. Currently, I am very interested in large scale next generation sequencing analysis using cloud computing. I hope I can provide some software solutions to help people who want to migrate the analysis from a local cluster to a cloud platform.



Tell us about some of your achievements-- any publications, leadership positions, and/or committees you have served on.
I have published 83 peer-reviewed papers with the majority of those being related to qualitative and quantitative proteomics, glycomics, next generation sequencing and multi-omics data integration. I am currently the Technical Associate Director of VANGARD (Vanderbilt Technologies for Advanced Genomics Analysis and Research Design).  In addition to that, I am leading a group to develop the NGS analysis framework in ACCRE which can dramatically improve the reproducibility and efficiency of data analysis.

What was your draw to the field of statistics and what are your goals?
Actually, my major was bioinformatics, but I have learned so much since joining the Center for Quantitative Sciences and then the Department of Biostatistics. I have learned that even with the very basic t-test, I need to make sure that the data truly supports the assumptions. I really believe that statistics is an essential part of both basic science and clinical research, and that the Department of Biostatistics will play more important roles in the Vanderbilt research community in the near future. Currently, I define myself as an entry-level biostatistician and an expert in bioinformatics. My goal is to apply my knowledge in precision medicine to help doctors and patients.

Can you share the status of any of your past students? What is your best advice for aspiring statisticians? 
I haven't had any students yet but I have guided a lot of our postdocs and staff members at various stages.  I really enjoy sharing my experience with people.

For those aspiring statisticians, I hope they can also work with some technical fields, such as code management, test driven development and even cloud computing. Those fields will make their research more robust, more efficient, and most importantly, more reproducible.

What makes Vanderbilt special in your experiences of collaborating with others? 
When I joined the team in 2012, I immediately felt the closeness from the collaboration between the basic science groups and clinical groups, and the discussions between the bioinformaticians and biostatisticians were amazing. It felt like a new window had opened up for me at that time. I have enjoyed this environment and getting the chance to work with all of the experts from different fields.  Today data science has become the hottest field in the world and I expect that statistics will play an essential role in healthcare data science in the future.

Tell us about your life outside of Vanderbilt. Do you have a significant other? Children? What are your goals for the future?
My wife and I have two lovely sons. I love to play basketball with friends at recreation center and with my kids at backyard. My goal is to keep my family safe and happy in the future.

Finally, what is something about you that most people at Vanderbilt still don't know about you? (Until now, of course!)
My colleagues definitely believe that I am such a kind, mild-mannered person, but you will see a different side to me on the basketball court; I become very focused and assertive.  And I have to admit that I am no good at remembering peoples' names.  So, if you ever meet me down by the court just know that I may not remember your name even though we may have met; please forgive me.

Today we are getting to know one of our Department's adjunct professors, Dr. Rafe Donahue.  Get the inside scoop about his research and interests!

What is the focus of your research and what have been the major findings so far?
As an adjunct faculty member working in industry, my research doesn't quite line up with the research of my strictly-academic colleagues.  The work I do, however, helps patients in a very direct sense, by getting products to market for the benefit of patients and health care providers.

The work that has kept me busy for the last decade or so revolves around a growth factor used in joint fusions, surgeries that eliminate pain by making two bones grow together across a joint that, typically, is damaged by arthritis and thus is painful.  This growth factor, we have shown, when properly applied, can be used in place of an autograft, a piece of the patient's own bone, harvested from elsewhere in the body.  These autografts can themselves result in problems, hence the value of a product that can be used in their place.

Tell us us about any recent publications you've had.
Our research typically gets published in major medical journals.  I was fortunate to get recent publications in Journal of Bone and Joint Surgery, Foot and Ankle Surgery, and Foot and Ankle International.

What was your draw to statistics at Vanderbilt and what have you learned as a statistician? 
The Vanderbilt biostats group is a vibrant team of fiercely-bright, top-notch professionals who are not only good statisticians, they are also good people. My relationship with Vanderbilt provides a strong connection to the academic world and provides valuable support to keep the work I do grounded.

Being a statistician has helped me understand how to look at data and see more than just means; it's about understanding variability and distributions.

What is your best advice for aspiring statisticians? 
My advice to aspiring statisticians is to commit to getting details right, whether they are statistical or scientific.  It's not good enough to say, "Well, that's good enough."  Credibility comes with getting the details right.  Learn the science; become conversant with your collaborators; don't accept being just a "Would you like fries with that analysis?" kind of statistician.  If your collaborators only want someone to compute p-values and sample sizes, get different collaborators.

Good statistics is about good design.  Fancy analyses will not save poor design.

Oh, and if your program takes days and days to run, either your analysis is too complex or your coding is not optimal.  Or both.  (That'll fire up somebody.)

What are your thoughts on controversial statistical topics such as adjusting the p-value for multiple comparison, the choice between Bayesian, likelihood, or frequentists, ethical issues, etc.?
General statistical rant:
We can be our own worst enemies sometimes because of how we teach statistics.  Look at the typical class: roll some dice, deal some cards, flip some coins, probability, conditional probability, here's how to compute a mean and a standard deviation and a median, here's how to do a t-test, f-test, chi-square test, regression, Bayes rule, use this R code to compute this, use this R package to compute that, use this SAS program to get data into a format for submission to FDA: everything we teach them is _technical_.

But if you go to seminar, the discussions aren't technical; they are strategic. "How does this impact the bias?"  "What does this do to the Type I error rate?"  "How does one present these data in the context of treating patients?"

So, people take our courses and they think that we are technical people doing technical work and they think, "I'll just save a ton of time and money and just download a copy of the super-EZ-stat app for Excel and I'll do this all myself!"  Or they think, "All I really need is a sample size and I'm too busy to do it myself; I'll just have the statistician compute that sample size for me when I'm in Boca next week."

But, as we statisticians know, it's much more complicated than that.  THIS STUFF IS REALLY HARD.  And it takes a lifetime to REALLY understand it.  There's a great article out there somewhere by Dick DeVeaux and a buddy called something like "Math is Music, Statistics is Literature"  It says that you can be a child prodigy in math and music because they are fields that are completely contained within themselves, so you can get folks like Mozart, who composed as a small child, and Guass, who showed, also as a small child, that the sum of the first n integers is (n)(n+1)/2.

But to write really good literature and to do really good statistics, you need to have life experience.  You need to understand the human condition and have seen the world in action.

Statistics isn't technical, even though we teach it that way.

Multiplicity/testing thoughts:
Feel free to do multiplicity adjustments but, better yet, show me the whole distribution of p-values (and not just the mean).  How do we deal with correlation?  How do we deal with the fact that in my lifetime I have look at thousands and thousands of p-values?  What's the impact of that?

P-values and inferential statistics only work in a narrow, forward-looking framework:  "If I run this experiment and if the null is true and if the data follow the distribution laid out in my plan, then the chance of a false positive outcome is 5%...".  Once the trial is run, everything is subject to all sorts of philosophical nuance.  We need to be very careful.

There's a big difference between inference from planned experiments and modeling data from EMRs and the like.  Bayesian stuff is great for things like that but not so much for planned experiments.

And let's not think that Bayesian methods, as slick and sexy as the math is, are a panacea for all the ills in our modern stats world.

Ethical issues thoughts:
This should go without saying but let's not lie or cheat or stack the deck or mislead.  We are nothing as statisticians if we aren't trustworthy.  We shouldn't have to teach that but if we do, so be it.

Tell us about your life outside of Vanderbilt. Do you have a significant other? Children?What about your hobbies and future goals? 

I have a wife of 27 plus years; we have a little doggie and live south of Nashville in warm and cheerful Nolensville.  We are active members of Holy Family Catholic Church in Brentwood.

We have three children.  Harry (b 1993) is a lieutenant in the Army stationed (currently!) in Tacoma, WA.  Zach (b 1994) is a second-year law student at the University of St. Thomas in Minnesota.  Olivia (b 1996) is an artist and care-giver living in Overland Park, KS.  They are wonderful sources of Joy and Light.

I have a couple of things that keep me busy outside of work.  We have a very large and well-organized Lego collection and we build things and go to conventions and all that.  We are part of a local Lego club that hosts an event every November at the public library in Nashville.  I typically build replicas of buildings I like or mechanical computing machines.

I also like to make sawdust in my workshop and the occasional furniture that might result from that.

I would love someday to own and run a working bison ranch but I'm thinking that's not going to happen.

Finally, what is something about you that most people at Vanderbilt still don't know about you?Here's something about me that most people don't know: I applied for the astronaut program at NASA several years ago.  I actually successfully navigated the application process and my credentials were  reviewed.  I was, of course, rejected; but I successfully made it through the process.  It was a very interesting experience!

This week we are excited to feature Cathy Jenkins, a Biostatistician IV, in the Vanderbilt Department of Biostatistics. Read on to learn more about her work and interests here at Vanderbilt:

What has been the focus of your research during your time in the Department?
For most of my time at Vanderbilt, I have split my time evenly between the Division of Infectious Diseases and the Department of Emergency Medicine.  My work with Infectious Diseases has been all HIV research using data collected locally, as well as from larger regional cohorts such as North America or Central and South America.  In one study, we saw that obesity is an increasing problem among persons living with HIV. The investigator I worked with on this project is interested in understanding HIV in the context of this obesity problem along with HIV in the context of the co-morbid conditions that come along with obesity.

My work with Emergency Medicine has largely focused on the management of heart failure in an acute care setting.  As the population ages, the number of people showing up to ERs with signs and symptoms of acute heart failure is increasing.  While it is clear who the sickest of the sick are and should be admitted, there is a large gray area where it is unclear how best to help patients manage their disease.  In one particular study using data from a large national emergency department database, we saw that on average about 80% of patients coming to the ER with acute heart failure were admitted.  This leads to huge costs both for the patient and the hospital.  Our goal is to be able to identify those who are safe for discharge from the ER to reduce the burden on both the patients and the hospitals.

How did you become a biostatistician?
I came to statistics by a very circuitous route.  I have an undergraduate degree in chemistry and a masters in applied math. I always enjoyed applications in the chemical/biological realms and found the teaching aspects that come along with working as a statistician appealing.  Just like with teaching, communication is key in my job. The investigators with whom I work have varying levels of statistical backgrounds so being able to adapt to their comfort level is a necessity.

What makes your role within Vanderbilt special? 
I have greatly appreciated all of the opportunities I have had here at Vanderbilt.  I started here in 2005, not too long after the department was started.  From the beginning, we have always been encouraged to be 'life-long learners' and given resources to help us with that.  I am grateful to be able to be a part of interesting research that is looking at current problems in need of sustainable solutions.

Tell us about your life outside of Vanderbilt. 
When I am not at work, I am typically doing something outside.  I have friends from my days at Auburn with whom I vacation every year.  We have hiked in many beautiful places including the Grand Canyon, Alaska, Olympic National Park, Maine, and the Canadian Rockies.  For the last several years, I've also done a few sprint triathlons.  I don't burn up the course by any means; my goal is to have fun and simply to finish!  And oh yeah, I am an Auburn football fan -- War Eagle!

Finally, what is something about you that most people at Vanderbilt still do not know about you? (Until now, of course!)
When I was in junior high, my entire class had to enter an oratorical contest sponsored by our local Optimist Club.  Shockingly, this introvert made it all the way to AL/MS districts!  You never know what you can do until you try!