CTRI's Biostatistics team includes (from left) Director Ronghui (Lily) Xu, Gordon Honerkamp-Smith, Jiayi Hou, James Proudfoot, Lishi Zhang, and Liyu Qin.

Overview and Vision | Statistical Support | Getting Assistance | FAQs | Other Resources


The Biostatistics Unit supports the mission of the CTRI to provide research resources, training, and collaboration opportunities for CTRI scientists, health care providers, and the community. We assist investigators at every stage of the research process to produce results that are rigorous, meaningful, and easy to communicate. We believe that the biostatistician should play an integral role as collaborator and co-investigator.

The Unit is directed by faculty member Ronghui (Lily) Xu, PhD, and is supported by five full- and part-time statisticians. We have experience in a broad range of research settings, with areas of interest that include clinical trials, longitudinal data, survival analysis, observational studies, and high-dimensional data.

Statistical Support

The Biostatistics Unit provides statistical support at all research phases. We encourage investigators to collaborate with biostatisticians beginning in the early stages. Areas of support include:

Study Design and Proposal Writing

  • Specifying and refining the research hypotheses.
  • Choosing the specific aims, primary and secondary outcomes, and appropriate statistical methods.
  • Reviewing the literature regarding relevant statistical methods.
  • Creating randomization assignments.
  • Performing sample size and power calculations.
  • Writing statistical analysis plans for grants and IRB submissions.
  • Responding to reviewer comments.

Study Implementation and Management

  • Designing efficient databases, performed in conjunction with Biomedical Informatics.
  • Advising for data entry etiquette, such as format and structure of data records, variable coding, and treatment of missing data.

Statistical Analysis

  • Reviewing data sets for quality and completeness.
  • Statistical software support, particularly for R and SAS.
  • Fitting of statistical models; scientific computing.
  • Interpreting, visualizing, and summarizing results.

Publishing and Communication

  • Generating internal statistical reports.
  • Editing and preparing abstracts and manuscripts for publication.
  • Producing journal-quality tables and graphics.
  • Responding to journal referees.

Getting Assistance

Request CTRI Services

All requests must be submitted using the above "Request CTRI Services" link. Investigators must become CTRI members before submitting the requests. Up to four hours of assistance is available to CTRI members for grant preparation without recharge.  After 4 hours, you will be charged the regular hourly rate. All investigators receiving biostatistics assistance during grant preparation are required to include biostatistics costs in the budgets for their grant proposals (a practice that usually strengthens the applications).


Since we usually work on multiple projects at a time, advance notice is strongly encouraged.

  • For grant submissions that do not involve preliminary data analysis, at least one month advance notice is required.
  • For grant submissions involving preliminary data analysis as well as for abstract submissions, at least two months advance notice is required. It is CTRI policy that a statistical analysis plan be formally approved by our co-investigators before analysis is carried out.

Recharge Rates

Biostatistics recharge rates are approximately $100/hour. Non-UCSD-funded users are charged slightly more.

Walk-in Consultation

Free walk-in biostatistics consultation is available every Wednesday from 1 P.M. to 5 P.M. in the East Campus Office Building (ECOB), Room 1-056, Phone: 858-657-5149. No appointment is necessary; assistance is provided on a first-come, first-served basis.

Frequently Asked Questions

Who can receive support?
CTRI membership is required in order to receive support. Please visit the membership page and apply for membership before requesting support. Investigators whose membership is pending may request support.

What happens after I submit my request for assistance? How long will it take to receive a response?
Your request will be reviewed and placed in our project queue, and an initial response will be made within 48 hours. The length of the queue depends on recent and current demand; response time can be anywhere from a few days to several weeks. When your project reaches the front of the queue, you will be contacted to arrange a face-to-face meeting. We recommend making a request as early as possible to ensure your deadlines are met (see the Timelines section above).

What will happen at the initial meeting?
The first meeting typically involves a supervising statistician, as well as one or more staff statisticians assigned to the project, and lasts no more than one hour. During the meeting, the background and research aims are discussed, and the goals of the project are outlined. Specific work items to be produced by the statistician are established (e.g., a power calculation or statistical analysis plan), including a timeline for delivery.

How will the project proceed?
After the initial meeting, the statistician will work to execute the planned objectives. Most projects will include a report detailing the results. For small projects, an analysis plan or analysis report may be sent to the investigator after the meeting; larger projects may involve multiple meetings or other communication as the investigator and statistician work together.

My deadline is this Friday, what should I do?
We are often engaged in multiple projects and generally are unable to accommodate last-minute requests. As a last resort, you may consider the weekly walk-in consultations; see above for details.

Considerations of co-authorship should be based on intellectual and research contributions, which include design, analysis, and interpretation, regardless of compensation. For more on authorship guidelines, see International Committee of Medical Journal Editors uniform requirements for manuscripts.

Other Resources