Motivation
The xportr package is designed to help clinical
programmers create CDISC compliant xpt files.
It provides the functionality to associate metadata information to a
local R data frame, perform data set level validation checks, and
convert into a transport v5 file (xpt). However, technical
requirements related to the xpt files can change across
different regulatory agencies. This vignette aims to start to provide a
clear and concise summary of the differences between the agencies for
the xpt files. Further updates will come with later package
releases.
The following section will delve into various technical specifications as per FDA, NMPA, and PMDA guidelines.
File name - character
XPT 
The first character must be an English letter (A, B, C, . . ., Z) or underscore (_). Subsequent characters can be letters, numeric digits (0, 1, . . ., 9), or underscores. You can use uppercase or lowercase letters. Blanks cannot appear in SAS names. Special characters, except for the underscore, are not allowed.
FDA 
Dataset in the transport file should be named the same as the transport file. Variable names, as well as variable and dataset labels should include American Standard Code for Information Interchange (ASCII) text codes only. Dataset names should contain only lowercase letters, numbers, and must start with a letter.
NMPA 
The file name and the dataset name must be the same for the SDTM and ADaM datasets. The Japanese dataset and alphanumeric dataset must be identical in structure, except for the data lengths of the Japanese items and the corresponding alphanumeric character sequence
PMDA 
Information has not yet been collected.
File name - length
XPT
maximum length of 8 bytes
FDA
8 characters
NMPA
-
PMDA
Information has not yet been collected.
Variable name
XPT
The name can contain letters of the Latin alphabet, numerals, or underscores. The name cannot contain blanks or special characters except for the underscore. The name must begin with a letter of the Latin alphabet (A–Z, a–z) or the underscore.
FDA
Variable names, as well as variable and dataset labels should include American Standard Code for Information Interchange (ASCII) text codes only. Variable names should contain only uppercase letters, numbers, and must start with a letter
NMPA
The Japanese dataset and alphanumeric dataset must be identical in structure, except for the data lengths of the Japanese items and the corresponding alphanumeric character sequence
PMDA
Information has not yet been collected.
Variable length
XPT
8 bytes
FDA
8 characters
NMPA
-
PMDA
Information has not yet been collected.
Label character
XPT
-
FDA
Variable names, as well as variable and dataset labels should include
American Standard Code for Information Interchange (ASCII) text codes
only. Do not submit study data with the following special characters in
variable and dataset labels: 1. Unbalanced apostrophe, e.g.,
“Parkinson’s” 2. Unbalanced single and double quotation marks 3.
Unbalanced parentheses, braces or brackets, e.g.,(,
{and [
NMPA
The Japanese dataset and alphanumeric dataset must be identical in structure, except for the data lengths of the Japanese items and the corresponding alphanumeric character sequence
PMDA
For eSubmission in China, one of the requirements is to translate the foreign language data package (e.g., English) to Chinese. Variable labels, dataset labels, MedDRA, WHO Drug terms, primary endpoint-related code lists, etc., need to be translated from English to Chinese.
Label length
XPT
40 bytes
FDA
40 characters
NMPA
-
PMDA
Information has not yet been collected.
Values character
XPT
-
FDA
Variable values are the most broadly compatible with software and operating systems when they are restricted to ASCII text codes (printable values below 128). Use UTF-8 for extending character sets; however, the use of extended mappings is not recommended. Transcoding errors, variable length errors, and lack of software support for multi byte UTF-8 encodings can result in incorrect character display and variable value truncation.
NMPA
If variables had been collected in Japanese and there is a risk of losing certain information by translating it into English, the descriptions in Japanese are necessary and appropriate, and data written in Japanese (hereinafter referred to as Japanese data) may be submitted. In the Japanese dataset, only the Japanese items should be Japanese and the rest should be alphanumeric(=ASCII) data, similar to that in the alphanumeric dataset.
PMDA
For eSubmission in China, one of the requirements is to translate the foreign language data package (e.g., English) to Chinese. Variable labels, dataset labels, MedDRA, WHO Drug terms, primary endpoint-related code lists, etc., need to be translated from English to Chinese.
Values length
XPT
200 bytes
FDA
The allotted length for each column containing character (text) data should be set to the maximum length of the variable used across all datasets in the study except for supplementary qualification datasets.
NMPA
-
PMDA
Information has not yet been collected.
Format
XPT
SAS format
FDA
SAS format
NMPA
-
PMDA
Information has not yet been collected.
Type
XPT
Numeric and character
FDA
-
NMPA
-
PMDA
-
File size
XPT
-
FDA
5 GB
NMPA
To be consulted if sponsors have datasets >= 5 GB No requirement to split datasets
PMDA
Information has not yet been collected.