...

This document describes the CDISC implementation of the 4 Stair Ascend (4 STAIR ASCEND) instrument.

There is no known standard case report form (CRF) available for this instrument. CDISC created this CRF to represent the instrument, which CDISC believes is in the public domain. This is not an endorsement of the instrument. The creation of this instrument was based on input from Duchenne muscular dystrophy subject matter experts. Sponsors may create this instrument’s CRF using their style guidelines, but they need to maintain the wording and order of the questions/items and responses (text and numeric) as described on the CRF.

The representation of data collected for this instrument is based on the Study Data Tabulation Model Implementation Guide (SDTMIG) Functional Tests (FT) domain model, which can be found on the CDISC website at: https://www.cdisc.org/standards/foundational/sdtmig.

These specific implementation details for this instrument are meant to be used in conjunction with the SDTMIG. All CDISC questionnaires, ratings, and scales (QRS) documentation packages can be found on the CDISC website at: https://www.cdisc.org/foundational/qrs.

The CDISC Intellectual Property Policy can be found on the CDISC website at: https://www.cdisc.org/about/bylaws.

1.1 Representations and Warranties, Limitations of Liability, and Disclaimers

...

Although the United States Food and Drug Administration (US FDA) has provided input with regard to this supplement, this input does not constitute US FDA endorsement of any particular instrument.

2 Copyright Status

CDISC believes this instrument to be in the public domain, but you should perform your own assessment. CDISC has included the 4 STAIR ASCEND in the library of QRS data standards supplements. Hence, CDISC developed FTTESTCD and FTTEST for each item based on the actual text on the instrument. There may be many versions of this instrument in the public domain or copyrighted. CDISC has chosen to use this version as the data standard.

The CDISC documentation of this instrument consists of: (1) controlled terminology, (2) standard database structure with examples, and (3) CRF(s) annotated with the CDISC SDTMIG variables with submission values.

Note: CDISC Controlled Terminology is maintained by National Cancer Institute (NCI) Enterprise Vocabulary Services (EVS). The most recent version should be accessed through the CDISC website at: https://www.cdisc.org/standards/terminology/controlled-terminology.

Reference for the 4 STAIR ASCEND: 

McDonald CM, Henricson EK, Abresch RT, et al. The 6-minute walk test and other clinical endpoints in duchenne muscular dystrophy: reliability, concurrent validity, and minimal clinically important differences from a multicenter study. Muscle Nerve. 2013;48(3):357-68.

3 The FT Domain Model

3.1 Assumptions for FT Domain Model

...

The 4 STAIR ASCEND is an instrument that records the time it takes to climb 4 standard stairs. The test also includes a clinician-rated numerical scale to record the clinician's observation on performance.

1. The numerical value for the time to complete the 4 STAIR ASCEND is recorded using ISO8601 format in FTORRES and FTSTRESC. Because ISO 8601 format is a text format, there are no standard numeric scores or units. The sponsor enters the time on the CRF in minutes and seconds according to their protocol. (e.g., 1 minute 10 seconds is represented in the FT domain in ISO 8601 format as "T1M10S")

2. For the test grade (where FTTESTCD = "A4STR104"), FTORRES is populated with the text description. The numeric rating is represented in FTSTRESC and FTSTRESN.

3. If the entire instrument was not done, the first question on the CRF represents the reason the entire instrument was not done. If the reason not done is provided, then FTSTAT = "NOT DONE" and FTREASND is equal to the text written on the form for all the test codes. 

   1. If the test was not done due to disease, the record where FTTESTCD = "A4STR101" will have FTORRES and FTSTRESC equal to "No, Due to disease under study" and the test grade (FTTESTCD = "A4STR104") will be represented with a value of 1 = "Unable to walk independently".

4. Some items on the 4 STAIR ASCEND may be logically skipped per the instrument instructions. If the test was not done because of disease, FTTESTCD = "A4STR102" and "A4STR103" are not done and are treated as logically skipped items. A record is created in ft.xpt for all items. When an item is considered a logically skipped item, it is represented as follows:

   1. FTSTAT = "NOT DONE"     

   2. FTREASND = "LOGICALLY SKIPPED ITEM"
      

   3. FTORRES, FTSTRESC, and FTSTRESN are set to null

   5. Terminology:
   

   1. FTCAT, FTTESTCD, and FTTEST values are included in CDISC Controlled Terminology.

   2. A full list of value sets for result and units fields is provided in Section 4, SDTM Mapping Strategy.

...

The 4 STAIR ASCEND example below shows the terminology used to implement the instrument in instrument in the FT domain. This example shows the data for 1 subject collected at the baseline visit for the 4 STAIR ASCEND instrument, and data for 1 subject 2 subjects who did not perform the test, one who refused and one who could not do the test because of disease progression. The example uses CDISC Controlled Terminology for FTTESTCD, FTTEST, FTORRESU, FTSTRESU, and FTCAT. All original results are represented with preferred terminology in FTORRES. This result is then transformed into a standard numeric score in FTSTRESN and a character representation of the standard numeric score in FTSTRESC.

The table represents the items from the 4 STAIR ASCEND form. USUBJID = "1001-001" did not perform the test due to the use of a wheelchair; however, the grade and orthoses question are still completed. form.

4

...

4 SDTM Mapping Strategy

This section is used for reference regarding the CRF data capture and to understand the alignment of the instrument to the SDTM FT domain. It also provides guidance on how the result and unit variables (FTORRES, FTSTRESC, and FTSTRESN, FTORRESU, and FTSTRESU) should be populated.

All responses for 4 STAIR ASCEND are numeric and units are predetermined for those result variables that have units. This section shows which units should be used for each FTTESTCD and FTTEST.

FTTESTCD = "A4STR101" FTTEST = "A4STR1-Was 4-Stair Ascend Performed"

FTTESTCD = "A4STR101A4STR103" FTTEST = "A4STR1-Time to Ascend 4 Stairs"Wear Orthoses"

FTTESTCD = "A4STR102A4STR104" FTTEST = "A4STR1-Test Grade"

FTTESTCD = "A4STR103" FTTEST = "A4STR1-Wear Orthoses"

End of Document