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Revision History

© 2021 2022 Clinical Data Interchange Standards Consortium, Inc. All rights reserved. 

1 Introduction

This document describes the CDISC implementation of the Psoriasis Area and Severity Index Version 2 Feldman (PASI V2FELDMAN) instrument. Note that Version 1 of the CDISC Controlled Terminology is scheduled for deprecation and an associated CDISC Version 1 instrument and SDTMIG QRS supplement were never released.

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

This document is a supplement to the SDTMIG for Human Clinical Trials and is covered under Appendix F of that document, which describes representations, warranties, limitations of liability, and disclaimers. Please see Appendix F of the SDTMIG for a complete version of this material.

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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 PASI V2in the CDISC library of QRS data standards supplements. Hence, CDISC developed RSTESTCD and RSTEST for each item based on the actual text on the instrument. There may be many versions of this instrument. CDISC has chosen to use this version as the data standard.

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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 PASI V2FELDMAN:

• Feldman SR, Krueger GG. Psoriasis assessment tools in clinical trials.

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• Ann Rheum Dis. 2005;64(

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• Suppl 2):ii65–ii68.
• CDISC believes this instrument to be in the public domain, but you should perform your own assessment.

3 The RS Domain Model

3.1 Assumptions for the RS Domain Model

All assumptions and business rules described in the SDTMIG RS domain are applicable to this supplement. Additional assumptions specific to the PASI V2 are FELDMAN are listed below.

The PASI V2FELDMAN is a tool used to assess the severity of psoriasis. However, there is no standard set of responses for the PASI that is used throughout the industry. This supplement uses the Feldman article as the standard for responses. The PASI V2 breaks FELDMAN divides the body up into 4 sections (i.e.,  headhead, trunk, upper extremities, lower extremities) and assesses symptom severity and the percentage of each area affected by psoriasis. The symptoms are rated on a 5-point scale and the area is rated on a 7-point scale. Subscores for each section of the body and a total score are also captured.

1. The scale points for the symptoms include a numeric rating (0-4) and a definition of what is represented by the rating (e.g., 0 = "None"). For the PASI V2FELDMAN, RSORRES is populated with the text description while ; the numeric rating is represented in the standardized character and numeric result variables RSSTRESC and RSSTRESN.

   1. CDISC created a CRF based on the Feldman article using the symptom terms "erythema/redness," , "thickness/induration," and "desquamation/scaling". As SMEs have recommended, we included desquamation ." Per subject-matter expert recommendations, desquamation was included with scaling even though desquamation is not referenced in the Feldman article.
      
2. The scale points for the area include a numeric rating (0-6) and a definition of what is represented by the rating (e.g., 0 = "No Involvement0 (clear)"). For the area, RSORRES is populated with the text description while ; the numeric rating is represented in the standardized character and numeric result variables RSSTRESC and RSSTRESN.
   

3. The PASI V2 instrument FELDMAN instrument includes subscores and a total score that are considered as captured data on the CRF and are not considered as derived in the example below. These scores may be submitted in SDTM or derived in the Analysis Data Model (ADaM) per scoring instructions from the Feldman reference.

   1. If operationally defined by the sponsor, it is the sponsor's responsibility to set the --DRVFL flag based on their eCRF process to derive subtotals and total scores. An investigator-derived score will be considered a captured score and not flagged. When subtotal and total scores are derived by the sponsor, the derived flag (--DRVFL) is set to "Y". However, when the subtotal and total scores are received from a central provider or vendor, the value would go into --ORRES and --DRVFL would be null (see SDTMIG Section 4.1.8.1, Origin Metadata for Variables).

   2. If scores are received by the sponsor, it is recommended that they are submitted to SDTM and verified in ADaM.

4. Records are created in rs.xpt for every item on the instrument: 

   1. For items with no data, RSORRES, RSSTRESC, and RSSTRESN are all missing and RSSTAT = "NOT DONE".  If the reason is known then , that reason is represented in RSREASND (e.g., RSREASND = "REFUSED"). If the reason is unknown, then RSSTAT = "NOT DONE" and RSREASND is missing.

5. Terminology

   1. RSCAT, RSTESTCD, and RSTEST values are included in CDISC Controlled Terminology.

   2. A full list of value sets for the result field is provided in Section 4, SDTM Mapping Strategy.

3.2 Example for the PASI

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FELDMAN RS Domain Model

The PASI V2 example below shows the terminology used to implement the instrument in the RS domain. This example shows the data for 1 subject collected at the baseline visit for the PASI V2 instrumentFELDMAN example below shows the terminology used to implement the instrument in the RS domain. The example uses CDISC Controlled Terminology for RSTESTCD, RSTEST, and RSCAT. All original results, matching the CRF item response text, are represented with preferred terminology in RSORRES. This result is then transformed into the represented as a standard numeric score in RSSTRESN and as a standard character representation of the standard numeric score in RSSTRESC.

The table represents the items from the PASI V2 instrumentFELDMAN instrument.

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 RS domain. It also provides guidance on how the result variables (RSORRES, RSSTRESC, and RSSTRESN) should be populated.

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RSTESTCD = "PASI0216" RSTEST = "PASI02-Low Extrem: Area Score"

End of Document