Medical Thesis Case Record Format — CRF Design Guide

The Case Record Form (CRF) is the primary data collection instrument in any clinical research study. It is the document completed for each patient at the point of care — either on paper or digitally — and it is the legal source document for your study. Your data sheet is derived from it, not the other way around.

Many students design their CRF after starting enrollment, or use a loose collection of notes. This guide shows you how to design a proper CRF before your first patient, what sections it must include, and how to format it for ease of use under clinical conditions.

CRF vs Data Sheet — What Is the Difference?

Students often confuse these two documents. The CRF is a human-facing form, completed in a clinical setting, that may include free-text notes, physical examination findings, and clinical sketches. It is the original record, and it must be retained for several years after thesis submission.

The data sheet is a structured spreadsheet extracted from the CRF — all numbers and codes, designed for computer analysis. Every value in your data sheet should be traceable back to a specific field on a specific CRF for a specific patient.

Standard Sections in a Medical Thesis CRF

CRF Design Principles

1. One CRF per patient per visit — If your study has follow-up visits, each visit should have its own CRF page or section, not share a sheet with the enrollment visit.
2. Ask only what you will analyze — Every field on the CRF must correspond to a variable in your data sheet. If you cannot define what you will do with a field analytically, remove it.
3. Use pre-coded checkboxes — Where possible, replace free-text fields with checkboxes or coded options. "Comorbidities: □DM □HTN □CKD □None" is far faster to complete and more reliable than a text field.
4. Include version control — Label your CRF with a version number and date. If you revise the form mid-study, keep both versions and note which patients were enrolled under which version.
5. Leave space for corrections — Paper CRFs should have adequate white space. Cramped forms lead to illegible entries.

Getting Your CRF Approved

Most institutional ethics committees (IECs) require the CRF to be submitted as part of the ethics application. The IEC-approved version becomes the official form, and any changes after approval require a formal amendment. Always use the IEC-approved version of your CRF from the first patient onwards.

Share the approved CRF with your thesis guide and ask for a review before enrollment begins. Guide feedback at this stage prevents expensive mid-study revisions.

Storing and Archiving CRFs

Completed paper CRFs must be stored securely for a minimum period after thesis submission (typically 5–10 years, depending on your institution's policy). Store them in a locked filing system, organized by Study ID. Do not store them with other patient notes. If using digital CRFs, the system must be password-protected and backed up regularly.