Biostatistics FAQ

We assign projects to statisticians each week. You should expect to receive an email from a statistician within 5-7 business days of your request to set up an initial consultation.

At the initial consultation, we review the statistical services you requested and ensure they align with your study objectives. We also discuss the scope of your project, the proposed timeframe for deliverables, and whether those deliverables are exempt from our rate structure. Ahead of this meeting, please provide your statistician with your study protocol.

For some projects, two hours of complimentary support is sufficient. If an investigator needs more support beyond these two hours, we will determine the remaining scope of work together. The remaining work will either compensate a named Biostatistician at an agreed proportion of his/her percent effort, or it will fall into one of four tiers: $250 if the remaining work does not require statistical analysis, $500 if the remaining work requires basic analysis services, $950 for standard statistical analysis services, and $2,500 for advanced analysis services.

Project tier depends on the complexity of data curation tasks and study design/analysis. Generally, the $250 tier includes additional study design consultation beyond the first complimentary two hours. The $500 tier includes descriptive and inferential analyses with simple designs and limited scope. Most clinical research projects fit in the standard analysis tier ($950) and include some level of both data curation and statistical modeling. The final $2,500 tier is meant for larger projects, such as study support for investigator initiated clinical trials, the analysis of nationally representative datasets (e.g., HCUP, NCDB, NHANES, etc.), or clinical prediction modeling/machine learning projects.

We invoice the accounting unit (AU) number at the time of IRB approval. If the project is already approved by the IRB, the AU number will be invoiced shortly after completing the initial two-hour consult.

The structure and format of the dataset is very important and needs to be tailored to your research aims. Any concerns regarding data cleaning, coding, and tracking should be addressed in the initial consult. As part of the collaboration, your assigned biostatistician will conduct an initial review of your data for quality assurance. If there are systemic errors or inconsistencies, it remains the responsibility of the research team to further clean and prepare the data. A formatted dataset should also include a list of variable names, variable definitions, and all assigned labels. This data dictionary facilitates the analysis and ensures results are accurate and interpretable.

Ideally, the statistician is involved in database design from the very beginning and helps to create the study database. We recommend using REDCap for data management, because it provides a secure method of storing data with validation methods to help prevent data entry errors.

The Biostatistics Collaborative Core requires a minimum of four weeks’ notice to meet an external deadline. Earlier notice may be necessary when our volume of requests is high or the scope of your project is large. If the need arises, you should contact the Director of the Biostatistics Collaborative Core, Cara Joyce, to discuss the project’s urgency, funding, and desired time-frame (cjoyce6@LUC.edu).

At any given time, statisticians are managing 20-40 active projects. Barring exigent circumstances, analyses are prioritized in the order they are received. However, Loyola investigators who fund our statisticians receive immediate priority. The biostatistician assigned to your project will work with you closely to set a reasonable and well-articulated timeline based on the scope of your study, while remaining sensitive to other investigators’ deadlines.

For any questions regarding your analysis or results, please contact your assigned statistician. Should any concerns or questions arise that cannot be addressed by your statistician, contact the Director of the Biostatistics Collaborative Core, Cara Joyce (cjoyce6@LUC.edu).

The required sample size for your study should be determined before you collect or analyze any study data.

For retrospective studies, we generally expect that all data meeting your inclusion and exclusion criteria are already included in the dataset at the time of the analysis. In these situations, we strongly recommend a single analysis performed after all data are collected.

For prospective studies the sample size should be determined from an a priori power analysis and sample size calculation. It is our policy that all interim analyses are planned before the very first subject is enrolled. Your consulting statistician will collaborate with you on the importance of the interim analysis plan (IAP) and will generate an IAP for your protocol. The IAP will list the specific and narrow hypotheses evaluated during an interim analysis. With some exceptions, these analyses usually exclude efficacy and instead focus on safety (e.g., adverse event rates, withdrawal rates, etc.).

The Biostatistics Collaborative Core supports investigator-initiated clinical and translational research that focuses on health and illness in humans. These include, but are not limited to, efforts to better prevent, screen, diagnose, and manage human outcomes. If you have any questions as to whether your study constitutes clinical research, please request our services using the Biostatistics Request Form, and your assigned statistician will follow-up with you.

We recommend authorship be determined as outlined by the International Committee of Medical Journal Editors: http://www.icmje.org/recommendations/browse/roles-and-responsibilities/defining-the-role-of-authors-and-contributors.html

It is advisable the research team agrees to authorship order and manuscript responsibilities before beginning any work on the project or manuscript. It is important to point out that using our provided methods, results, tables, or figures verbatim and without our permission may be considered plagiarism by some journals.

Core Biostatisticians support educational and mentorship opportunities across the health sciences campus. We welcome providing complimentary seminars in statistics for students, residents, and clinicians upon request. You may request a lecture or seminar series using our online request form.

As part of our department’s ongoing efforts to improve our services, we welcome your feedback on all collaborations. The information you provide is considered confidential and anonymous, though aggregate information may be shared internally or with department administrators to further improve our core.

You can provide feedback using the Biostatistics Feedback Form. Otherwise, if you have any questions or concerns, please feel free to contact the Director of the Biostatistics Collaborative Core, Cara Joyce.