If your MD, MS or DNB thesis tests an intervention, there is a good chance someone will ask you for a CTRI number: your guide, your IEC, your university, or a journal editor two years later when you try to publish. Many residents discover this too late, after recruitment has begun, when prospective registration is no longer possible.
This guide explains what the Clinical Trials Registry–India (CTRI) is, which thesis studies are usually registered, when to register, the main fields you will fill, and the reasons registrations get delayed. Requirements differ between institutions and journals, and CTRI updates its own rules from time to time, so treat this as a practical overview and confirm the current position with your institution, your IEC and the CTRI website itself.
1What CTRI Is
CTRI is India's online public registry for clinical studies, available at ctri.nic.in. It is hosted by the ICMR's National Institute of Medical Statistics (ICMR-NIMS) and is a Primary Register in the World Health Organization's International Clinical Trials Registry Platform (ICTRP). Registration is free.
A registry record publicly declares, before the study starts, what you plan to do: the population, the intervention and comparator, the primary and secondary outcomes, and the planned sample size. That record later lets examiners, editors and readers check that the outcomes you report are the ones you planned, which protects against selective reporting.
When a record is accepted, CTRI issues a registration number in the format CTRI/year/month/serial number. That number goes into your thesis, your manuscript abstract and your methods section.
2Does Your Thesis Need CTRI Registration?
There is no single answer for every thesis, so be careful with blanket statements you hear in the department. What can be said with confidence:
- Regulated clinical trials: registration on CTRI has been mandatory for clinical trials regulated by the Drugs Controller General of India since 2009.
- ICMR guidelines: the ICMR National Ethical Guidelines (2017) expect clinical trials to be registered with CTRI before enrolment of the first participant.
- Journals: journals that follow the ICMJE Recommendations require clinical trials to be registered in a public registry at or before the time of first participant enrolment, as a condition for considering the paper. ICMJE defines a clinical trial broadly: any research project that prospectively assigns people to an intervention, with or without a comparison group, to study the relationship between a health-related intervention and a health outcome.
Under that ICMJE definition, many thesis studies count as clinical trials even when the drugs are routine: a randomised comparison of two anaesthetic agents, two suture techniques, two physiotherapy protocols, or an educational intervention with a health outcome. If you hope to publish such a study, register it.
| Thesis design | Registration |
|---|---|
| Randomised controlled trial (drug, procedure, device, behavioural) | Register prospectively |
| Non-randomised interventional study (assigning participants to an intervention) | Register prospectively; usually treated as a trial by journals |
| Prospective observational cohort or cross-sectional study | Often not required; register if your institution or target journal asks |
| Retrospective record-based study | Usually not registered |
| Diagnostic accuracy study | Varies; check your institution and target journal |
Some universities and IECs ask every PG thesis with an intervention, or even every prospective thesis, to be registered on CTRI. Others leave it to the guide. Ask your IEC office what your institution requires, and look at the author instructions of the journal you plan to target before deciding.
3When to Register
The rule is simple: register before the first participant is enrolled. The practical sequence for most thesis studies is:
- Protocol finalised and approved by the department.
- IEC approval obtained (see our guide on IEC approval for an MD/MS thesis).
- CTRI application submitted, queries answered, registration number issued.
- First participant enrolled.
CTRI asks for ethics committee approval details as part of the record, so in practice you register after IEC approval. You may be able to start filling the form while the IEC is reviewing your file, which saves time; but do not enrol anyone until the record is registered.
A trial registered after enrolment began is labelled retrospectively registered, and journals following the ICMJE Recommendations may decline to consider it. CTRI's own policy on accepting retrospective registrations has changed over time. Do not plan on registering later; build CTRI time into your schedule.
4Step-by-Step Registration
- Create a registrant account on the CTRI website with a working email address you check regularly. Decide with your guide whose account will hold the record.
- Start a new trial record and fill each section. You can usually save and return to it.
- Upload or enter the ethics approval details as the form requests.
- Submit the record for review.
- Answer CTRI queries. CTRI staff review the record and may return it with comments. Edit and resubmit promptly.
- Receive the registration number once the record is accepted. Save a PDF of the registered record for your thesis file.
5The Main Fields You Will Fill
CTRI fields broadly follow the WHO Trial Registration Data Set. Expect to provide the following, and keep your protocol open while you fill them so that every entry matches:
| Field | What to enter |
|---|---|
| Public and scientific titles | A plain-language public title and a scientific title that names the design, for example "A randomised controlled trial comparing..." |
| Secondary identifiers | IEC reference number or protocol number, if any |
| Principal investigator and contacts | Name, designation, affiliation and contact details; check whether your institution wants the guide or the resident named as PI |
| Sites of study | Department, hospital and address |
| Ethics committee | Name of the IEC, approval status and date |
| Regulatory status | Whether DCGI approval applies or is not applicable |
| Health condition | The condition studied, often with a standard classification code |
| Intervention and comparator | Drug, dose, route, frequency and duration, or a clear description of the procedure or programme |
| Inclusion and exclusion criteria | Age range, sex and the key criteria from your protocol |
| Randomisation, allocation concealment, blinding | Method used for each, or "not applicable" |
| Primary and secondary outcomes | Each outcome with its time point(s) of measurement |
| Target sample size | Total and per group, matching the protocol |
| Phase, dates and status | Phase (or "not applicable"), anticipated date of first enrolment, duration and recruitment status |
| Brief summary | A short plain summary of the study |
"Pain score" is not an outcome entry. "Pain score on a 0–10 numerical rating scale at 2, 6, 12 and 24 hours after surgery" is. Write primary and secondary outcomes exactly as in your protocol, and use the same wording later in the Results chapter.
Worked example: intervention and outcome entries
Suppose your thesis compares two drugs for preventing shivering after spinal anaesthesia. Weak entries and stronger entries might look like this:
| Field | Weak entry | Stronger entry |
|---|---|---|
| Intervention | Drug A | Drug A, dose as per protocol, given intravenously once, at a stated time relative to the spinal block |
| Comparator | Drug B | Drug B, dose, route and timing as per protocol, given in the same way |
| Primary outcome | Shivering | Incidence of shivering, graded on the scale named in the protocol, assessed at fixed intervals for a stated period after the block |
| Secondary outcomes | Side effects | Each side effect named separately (for example nausea, sedation score, hypotension), with the tool and time points |
The stronger entries let anyone reading the registry know exactly what you will measure, which is the whole point of registration. They also make it easy to check later that your Results chapter reports the same outcomes.
Your sample size entry should match the calculation in your synopsis; our sample size guide explains how to present it.
6Common Reasons for Delays
- Mismatch with the protocol: sample size, outcomes or criteria differ from the IEC-approved protocol.
- Vague outcomes: no measurement tool or time point.
- Unclear intervention: no dose, route, timing or duration.
- Missing ethics details: approval letter not yet available or not uploaded as required.
- Title problems: the scientific title does not state the design or population.
- Anticipated start date in the past: suggests enrolment has already begun.
- Slow replies: the record waits while queries sit unanswered in an inbox nobody checks.
- Incomplete sections: randomisation, concealment or blinding left blank instead of marked as not applicable.
Most of these delays can be prevented with one habit: fill the CTRI form with the IEC-approved protocol open beside you, and copy the wording of objectives, criteria, outcomes and sample size directly from it. If the IEC asked for changes, make sure you are working from the final approved version, not an earlier draft. Before submitting, ask your guide to read the record once; a second reader often catches a missing time point or a mismatch in group sizes.
When CTRI returns a record with queries, reply to every point, not just the first one. Partial replies tend to come back again, and each round adds waiting time before you can enrol your first participant.
7After Registration
- Keep the record updated. Change the recruitment status when recruitment starts and ends, and update the record if an IEC-approved amendment changes key details.
- Cite the number. Mention the CTRI number in the Methods chapter of your thesis and in the abstract and methods of any manuscript.
- Report what you registered. Your Results should report the registered primary outcome. If something changed, explain it honestly; examiners and editors can compare.
The registration is part of the larger thesis timeline described in our step-by-step MD/DNB thesis guide.
8Getting Help with CTRI Registration
CTRI records go smoothly when the protocol behind them is clear and consistent. If you would like help aligning your protocol, outcomes and sample size before you fill the CTRI form, or a check of your draft entries, the PubMedico team can assist. Message us on WhatsApp at +91 78787 33004.
❓ Frequently Asked Questions
Quick answers to common questions on this topic
No single rule covers every thesis. Registration is mandatory for clinical trials regulated by the DCGI, the ICMR 2017 guidelines expect clinical trials to be registered, and ICMJE journals require prospective registration of trials. Many institutions ask for it for all interventional theses. Observational theses are often not registered. Check your IEC's and university's current requirements.
You should not plan to. A record registered after enrolment began is marked as retrospectively registered, CTRI's acceptance policy for such records has changed over time, and journals following ICMJE may refuse to consider the trial. Register after IEC approval and before the first participant, and keep enough time for CTRI queries.
CTRI registration is free. You need a registrant account with a valid email address, your IEC-approved protocol and the ethics approval details. The time cost is real, though, because the record is reviewed and may be returned with queries, so start early and reply quickly.
Practice varies between institutions. Some list the PG resident as principal investigator with the guide as a contact, while others prefer the guide as PI. Follow your institution's or IEC's convention and make sure the names and roles match your IEC approval letter and protocol.
State the CTRI registration number and the date of registration in the Methods chapter, usually alongside the IEC approval details, and attach a copy of the registered record in the annexures if your university allows. Include the number in the abstract and methods of any manuscript you publish from the thesis.
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