Field 1. Primary Registry and Trial Identifying Number

WHO description

Name of Primary Registry, and the unique ID number assigned by the Primary Registry to this trial.


String type, non-repeating, non-editable, unique field.


System-assigned value.


EN: BRTN: Rebrac Trial Number

PT: BRTN: Identificador do ensaio no Rebrac

ES: BRTN: ???

Sample Values

sample 1
sample 2
sample 3


Executive Committee decisions (2009-08-06):

  • BRTN will only be assigned when the CT record is published by a reviewer.
  • BRTN should be generated non-sequentially, to prevent a trialist from "guessing"

(use this area to post further suggestions)

Question: Should the REBRAC require that the registrant obtain a UTRN prior to publishing a trial record?

Answer: We can apply the same procedure used by Clinical Trial Registry - India, as stated in their data set description: "The UTRN is a number, obtained by the trial's sponsor or principal investigator from as the first step in registering a trial on the CTRI. The UTRN will then become part of the trial's international identity along with the CTRI registration number. A trial may have a UTRN but may not be fully registered in the CTRI and receive only a provisional CTRI number unless all required dataset items are fully disclosed."

Part of: TrialRegistrationDataSet

Formato de identificador primário de ensaio do REBEC

Exemplo: RBR-2b3ck7

O formato é RBR (em caixa alta), seguido de um hífen, seguido de um dígito aleatório de 2 a 9, seguido de mais 5 caracteres aleatórios escolhidos entre estes: 23456789bcdfghjkmnpqrstvwxyz.

Houve a preocupação de projetar um formato "amigável" e facilmente reconhecível. Usamos letras e números para evitar recorrer a números muito extensos: com 6 caracteres podemos ter 137.682.944 combinações. Propositalmente excluímos da parte variável do identificador os caracteres "1l0o" porque eles podem ser confundidos entre si, e excluímos todas as vogais para evitar a formação de palavras na maioria dos idiomas.

Não misturamos caixa alta e caixa baixa na parte variável, para podermos receber consultas em qualquer formato sem distinção, ou seja, para o sistema todas as formas a seguir serão aceitáveis na busca e produzirão o mesmo resultado:

RBR-2b3ck7, RBR-2B3CK7, RBR-2b3ck7, rbr-2b3ck7

Porém vamos armazenar, exibir e exportar sempre no formato "oficial" que é RBR-2b3ck7.

O código que gera o número está na função generate_trial_id neste arquivo:


REBEC primary trial ID format

Example: RBR-2b3ck7

The format is split in 2 parts:

RBR- : this is a fixed prefix, present in all primary trial IDs issued by REBEC; the letters stand for Brazilian Registry (in Portuguese)

2b3ck7 : this variable part is generated randomly, subject to two rules: (1) the first character is always a digit from 2-9 and (2) the remaining 5 characters are drawn from the set "23456789bcdfghjkmnpqrstvwxyz"

This format was designed to be user friendly and easily recognizable. We used letters and numbers to avoid generating very long numbers: with our rules we can generate 137,682,944 combinations. We intentionally excluded from the set of characters used "1l0o" because the can be confused, and we excluded all vowels to avoid forming words in most languages.

We do not mix upper and lower case in the variable part so we can accept queries regardless of case, i.e. the system can accept all the following forms, returning the same result for all:

RBR-2b3ck7, RBR-2B3CK7, RBR-2b3ck7, rbr-2b3ck7

But we will always store, display and export the "official" format which is RBR-2b3ck7.

The source code that generates the id is in the generate_trial_id located in this file: