A clinical study report is rarely one file. It is a synopsis, a report body, a protocol, amendments, listings and datasets, sometimes spread over several sequences. The study tagging file is what tells the reviewer these files belong to one study, and what each one is.
Key takeaways
- An STF is a small XML file that groups a study’s documents and tags each one.
- FDA expects STFs for studies in Modules 4 and 5 in eCTD 3.2.2; other regions differ.
- Most STF findings are about attributes: missing, duplicated or not called for.
- eCTD 4.0 does not use STFs; study grouping moves into the submission itself.
What a study tagging file is
A study tagging file (STF) is an XML file defined by ICH for eCTD 3.2.2. There is one per study. It records the study’s identifier and title, any category information the section calls for, and a list of the study’s documents — each with a file tag that says what the document is: a synopsis, the study report body, the protocol or an amendment, a data listing, and so on.
Review tools use the STF to show a study as one unit, with its documents arranged by role, instead of a flat list of PDFs in a section folder. Without it, a reviewer has to open files to work out which belong to which study.
When you need one
In the US, FDA expects an STF for each study in Modules 4 and 5 of an eCTD 3.2.2 submission — nonclinical study reports in Module 4 and clinical study reports in Module 5. Requirements in other regions differ, and some do not use STFs at all, so check the regional guidance for every region you file in.
Because a study can grow across sequences — a final report after an interim, an amended protocol, additional datasets — its STF has to be kept up to date as documents are added or changed, so that the study still reads as one unit in the current view.
File tags: say what each document is
Each document listed in the STF carries a file tag from ICH’s list of valid values. Choosing the right tag matters: it decides where the reviewer’s tool shows the document. Tag a protocol amendment as the report body and it appears in the wrong place. Agree the tags as part of your granularity plan, so authors split reports along the same lines the tags expect. See our guide to document granularity.
The STF is invisible until it is wrong. Then the reviewer cannot find the study.
The findings that catch most teams
FDA’s validation criteria include a group of checks on STFs. A few come up again and again:
- A doc-content title in the STF (FDA criterion 3001, medium). The title inside the STF is not visible to the reviewer; the leaf title is. FDA recommends not using it.
- A required attribute missing, for example the type of control for a study in section 5.3.5.1.
- An attribute repeated (criterion 1362, medium), such as two type-of-control values. The viewer shows only the first.
- An attribute not called for (criterion 1368, low), such as species in a Module 5 STF.
- Elements in the wrong order (criterion 3015, medium), such as a file tag placed before its property element.
None of these is hard to fix, and all of them are easy to prevent if the STF is generated from the study’s data rather than written by hand. The full list is on our FDA validation criteria page.
What changes in eCTD 4.0
eCTD 4.0 does not use separate STF files. Information about which study a document belongs to, and what the document is, is carried in the submission itself. If your applications will move to 4.0, keep your study identifiers and document roles clean now — they are the data a 4.0 submission will need. Our eCTD 4.0 readiness guide covers the rest.
How DnXT approaches it
DnXT Publisher builds study tagging files from the study and its documents, with file tags chosen from the valid list, and validates them with the rest of the sequence against FDA’s criteria at FDA’s severity.
Clinical and nonclinical sections, done right
Talk to our publishing team, or see STFs built and validated in DnXT Publisher.
