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Real Talk: Eosinophilic Diseases

Sep 28, 2022


Co-hosts Ryan Piansky and Holly Knotowicz, MS, CCC-SLP, talk with guest Kara Kliewer, RD, PhD, about longitudinal research studies.


Dr. Kliewer is a clinical research manager at Cincinnati Children’s Hospital Medical Center in the Division of Allergy and Immunology. She has a doctorate in nutrition and has teamed up with other researchers to manage multi-site clinical trials in eosinophilic disorders, oversee coordinators managing industry-sponsored clinical trials, and collaborate and assist with research projects at the Cincinnati Center for Eosinophilic Disorders. She is also a member of the Consortium of Eosinophilic Gastrointestinal Disease Researchers, also known as CEGIR.


In this episode, Holly and Ryan discuss with Dr. Kliewer her background and experience with research studies for eosinophilic disorders. Dr. Kliewer explains what a longitudinal study is, how long it can last, what kind of data it can gather, and the benefits of this type of research. She shares how easy it is to enroll in a longitudinal study and the time commitment that is often expected from participants. Dr. Kliewer also notes the types of interventional studies she works with and what kinds of commitments are expected of participating patients. She also shares how patients can enroll in longitudinal or cross-sectional studies. Finally, Dr. Kliewer discusses her current work and upcoming research. Listen in to learn the valuable findings longitudinal studies can produce.


Disclaimer: The information provided in this podcast is designed to support, not replace the relationship that exists between listeners and their healthcare providers. Opinions, information, and recommendations shared in this podcast are not a substitute for medical advice. Decisions related to medical care should be made with your healthcare provider. Opinions and views of guests and co-hosts are their own.


Key Takeaways:

[1:25] Holly shares the topic of this episode, longitudinal research studies, and introduces today’s guest, Kara Kliewer, RD, PhD.


[1:31] Dr. Kliewer is a clinical research manager at Cincinnati Children’s Hospital Medical Center in the Division of Allergy and Immunology. She has a Ph.D. in nutrition and is a registered dietitian. She is also a member of the Consortium of Eosinophilic Gastrointestinal Disease Researchers, also known as CEGIR.


[2:02] Holly welcomes Dr. Kliewer to the podcast.


[2:17] Dr. Kliewer’s background is in nutrition science. About eight years ago, Dr. Kliewer began managing and coordinating clinical trials for eosinophilic disorders.


[2:27] At first, Dr. Kliewer’s studies were mostly about nutrition. They have expanded into other clinical trials, testing drug interventions, and doing cross-sectional studies, and longitudinal studies, all with patients with eosinophilic gastrointestinal diseases.


[2:45] Dr. Kliewer assists with the design of investigator-sponsored studies, she manages the coordinators that are enrolling patients in studies, and she works with the statisticians at the end of the study to help with the analysis. She is engaged in all sides of the study from the beginning to the end.


[3:13] A longitudinal study takes repeated measures of individual patients, over time. Almost always, those studies are observational. A well-known longitudinal prospective study is the Nurses’ Health Study. It started in Harvard in the 1970s and is ongoing. It studies the lifestyle habits of women and the diseases they develop over time.


[4:00] Dr. Kliewer’s group started doing prospective longitudinal studies in eosinophilic disorders, looking at how chosen variables might change over time in relation to other variables.


[4:18] Rarely, there can be some interventions associated with a longitudinal study, but it’s quite uncommon for there to be anything other than observation of the people in the study.


[4:34] Longitudinal studies can last for decades. In general, they last one to two years or five to ten years. A short-term study can be for a couple of weeks.


[4:51] Dr. Kliewer’s studies may last five to ten years. Because they are conducted at a children’s hospital, some patients “age out.” In some cases, the study team may follow up with those patients. If the study is coordinated with another organization, the patients can be followed when they transition to adult care.


[5:43] The observational longitudinal studies, in general, are pretty open for participants who meet the age requirement and have the disease being studied, unlike interventional studies where the inclusion/exclusion criteria are rigorous, due to questions of drug safety. 


[6:30] Dr. Kliewer says that from these longitudinal studies we learn about relationships between various factors and the disease, its development, or progression. Usually, the studies are focused on particular variables and how they may change with time, how the disease progresses, and what factors might influence that.


[6:59] You might observe how symptoms change over time and also how they change with eosinophilic counts. The studies generate hypotheses and give relationships to research further, focus on, and help to develop clinical interventions or treatments for the disease, and just generally, know more about the disease.


[7:48] Dr. Kliewer tells how the data changing over time in a longitudinal study is helpful. Over time, you can observe more patterns. The longer you follow, the more you can learn about the disease’s progress. In a cross-sectional study, you are looking at a set of patients that is limited in terms of understanding all patients.


[8:32] Patients in a longitudinal study enjoy participating. The time commitment is minimal because the study piggybacks off of the yearly or twice-yearly clinical visits, taking 15 to 30 minutes of their time. It’s a good way to be involved in research.


[9:56] Administrative challenges include patients losing enthusiasm over the years and not being as interested to talk to the researchers when they are older. It is expensive to continue studies for years. Some patients age out of pediatric care and it’s a challenge to keep in contact with them by phone or catch up with them at another site.


[10:49] For patients enrolling in the study, when they learn the time commitment is minimal, they are happy to participate in a longitudinal study. In general patients have a good grasp of what a longitudinal study entails.


[11:40] Dr. Kliewer explains the commitments of an interventional study. Patients come in monthly in addition to their clinical care visits, and almost daily fill out a questionnaire. Developing a good relationship with the patients works well. The coordinators get to know the families. Everybody’s working toward a goal. 


[12:53] Dr. Kliewer tells how data from multiple studies can be pooled or compared.


[13:36] Dr. Kliewer is involved in various clinical trials. Some are interventional, industry-sponsored, testing therapies. Some are observational. They participate in longitudinal studies as part of a consortium. Some cross-sectional, studies obtain biological specimens to try to understand the mechanisms that underlie the disorders.


[14:53] Dr. Kliewer and her team learned about running a longitudinal study during COVID-19. When there were no clinic visits it was a challenge for the studies. The studies are up and running again.


[15:40] CEGIR researchers have published some of the results of Dr. Kliewer’s longitudinal studies. Most publications have been on cross-sectional studies.


[16:01] Dr. Kliewer’s publications include looking at the molecular changes of eosinophilic gastritis and a cross-sectional view of symptoms in children and parents’ symptoms compared to their children, which they found correlated. Now that they have reached the five-year mark, some of the longitudinal data is being analyzed.


[17:02] Other longitudinal observational studies are listed on, including trials that are recruiting patients.


[17:52] Patients hoping to get involved with an interventional study can ask their gastroenterologist or allergist for information on studies. Your provider knows what would be a good fit for you. For any study, carefully read the consent form, and be sure to ask the coordinator all the questions that you have, before enrolling in a study.


[18:51] Consent forms vary depending on if the study is interventional and testing a pharmaceutical product, or observational. Consent forms include the benefits and risks, the time commitment, and the procedures patients will be asked to do. Know what your commitments are before enrolling.


[19:37] Dr. Kliewer has a number of additional interventional studies in the pipeline, including research on drugs that could potentially affect eosinophilic esophagitis. Other upcoming research is focused on eosinophilic gastritis, enteritis, and colitis.


[20:57] Dr. Kliewer is grateful that patients become engaged in this research. It’s one of the few ways we have to find out how the disease progresses and potentially develop better treatments. She hopes people have learned that the time commitment is not a lot but the benefit to research will be a lot.


[22:15] Ryan invites listeners to look at and to learn more about eosinophilic research. Ryan also encourages you to join the APFED online community at Ryan thanks Dr. Kliewer for joining us today.


[22:56] Dr. Kliewer thanks Ryan and Holly for having her on the podcast.


Mentioned in This Episode:

American Partnership for Eosinophilic Disorders (APFED)

APFED on YouTube, Twitter, Facebook, Pinterest, Instagram

Kara Kliewer, RD, PhD

Cincinnati Children’s Hospital

Allergy and Immunology, Cincinnati Children’s Hospital

Nurses’ Health Study


Dr. Evan Dellon

APFED EOS Connections Online Community

Real Talk: Eosinophilic Diseases Podcast


This episode is brought to you thanks to the support of our Education Partners Abbott, Bristol Myers Squibb, GlaxoSmithKline, Mead Johnson Nutrition, Sanofi, and Regeneron.




“A longitudinal study is one that involves taking repeated measures of … the same individuals over time. … Those studies are observational. …  A well-known longitudinal prospective study is the Nurses’ Health Study and it started in Harvard in the ’70s.” — Dr. Kara Kliewer


“Some [longitudinal studies] can last decades; others can be very short. In general, they’re at least a year long.” — Dr. Kara Kliewer


“Some of the advice that we constantly give is always talk to your gastroenterologist or allergist, especially if you’re interested in an interventional study because your provider probably knows … what would be a good fit for [you].” — Dr. Kara Kliewer


“Carefully read the [clinical trial] consent form, know what you’re getting yourself into, and be sure to ask the coordinator … all the questions that you have before beginning the study.” — Dr. Kara Kliewer