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Revision History

© 2021 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 (PASI V2) Version 2 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 PASI V2 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 as described on the CRF.

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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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Feldman SR, Krueger GG. Psoriasis assessment tools in clinical trials. Ann Rheum Dis. 2005;64(Suppl 2):ii65–ii73.

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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 listed below.

The PASI V2 is a tool used to assess the severity of psoriasis. The PASI V2 breaks the body up into 4 sections (i.e., head, trunk, upper extremity, lower extremity) 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.

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 listed below.

The PASI V2 is a tool used to assess the severity of psoriasis. The PASI V2 breaks the body up into 4 sections (i.e., head, trunk, upper extremity, lower extremity) 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 (i.e., erythema/redness, thickness/induration, desquamation/scalingThe scale points for the symptoms (i.e., erythema, infiltration, desquamation) include a numeric rating (0-4) and a definition of what is represented by the rating (e.g., 0 = "None"). For the PASI, RSORRES is populated with the text description while the numeric rating is represented in the standardized character and numeric result variables RSSTRESC and RSSTRESN.) and a definition of what is represented by the rating (e.g., 0 = "None"). For the PASI V2, 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 input from subject-matter experts and the Feldman reference article.
      
   2. The Feldman article uses the symptom terms "erythema", "induration" and "scale". However, the terms "redness", "thickness" and "desquamation" are also used regularly, therefore, both version of the symptom terms are used on the CDISC created CRF and in the terminology for RSTEST
   3. CDISC created a CRF based on input from subject-matter experts and the original Fredriksson reference article.
      
   4. The Fredriksson article is the original reference for the PASI; however, the Symptom Score response choices have changed over time to "None", "Slight", "Moderate", "Severe", and "Very Severe" as supported in the Feldman reference above. CDISC subject matter experts agreed to use these responses as the data standard.
   5. The Fredriksson article has an apparent error showing the trunk percentage of the total score being multiplied by 20% in the text on the bottom of page 2; however in the formula highlighted on the page 3, and in other reference articles including Feldman, 30% is used for the trunk percentage of the total score. CDISC subject matter experts agreed to use 30% for the trunk percentage of the total score.
      
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 Involvement"). For the PASIarea, 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 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 are considered as captured data when provided as part of Electronic Data Transfer (eDT) and are not considered as derived in the example below may be submitted in SDTM or derived in the Analysis Data Model (ADaM) per scoring instructions from the Feldman reference.

   1. 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

      written on a CRF

      1. 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. 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.

1. Include a description of scale score or other possible responses (You may need multiple numbered points for this, tho the IDS-SR did not.). For scale scores use the following language: The scale points include a numeric rating (0-3) and a definition of what is represented by the rating (e.g., 0 = "I never take longer than 30 minutes to fall asleep"). For the QRS Short_Name, QSORRES is populated with the text description while the numeric rating is represented in the standardized character and numeric result variables QSSTRESC and QSSTRESN.

2. Include a description of the evaluation interval if one exists. This may be numeric (QSEVLINT) or text (QSEVINTX). When the evaluation interval is provided in text and cannot be described in ISO 8601 format, use QSEVINTX instead of "QSEVLINT field in ISO 8601 format" and replace "the past 7 days" with the text (e.g., "DAYTIME'". Refer to SDTMIG Section 2.2.5 Timing Variables for All Classes. The evaluation interval needs to be clearly defined on the CRF. Remove this point if it does not apply.: The time period of evaluation for theQRS Short_Name is populated in the QSEVLINTfield in ISO 8601 format (or QSEVINTX, as appropriate) when the evaluation interval can be precisely described as duration. The evaluation interval for the QRS Short_Name is the past 7 days (QSEVLINT = "-P7D"). Alternatively, if it cannot be described as an ISO 8601 duration:  The time period of evaluation for the QRS Short_Name is populated in the QSEVINTX field as an evaluation interval text value, since it cannot be precisely described as an ISO 8601 duration.

3. If there are subcategories, include a note that subcategories will be represented in QSSCAT. Also provide a list of the subcategories unless one is already provided in the description preceding the assumptions. Remove this point if it does not apply.  For example:  Items are divided into 5 subcategories represented in QSSCAT: "PHYSICAL WELL-BEING", "SOCIAL/FAMILY WELL-BEING", "EMOTIONAL WELL-BEING", "FUNCTIONAL WELL-BEING", and "ADDITIONAL CONCERNS".

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

   1. For items with no data, QSORRES, QSSTRESC, and QSSTRESN are all missing and QSSTAT = "NOT DONE".  If the reason is known then that reason is represented in QSREASND (e.g., QSREASND = "LOGICALLY SKIPPED ITEM" or QSREASND = "PREFER NOT TO ANSWER"). If the reason is unknown, then QSSTAT = "NOT DONE" and QSREASND is missing.

5. If the instrument standards currently being developed includes logically skipped items, insert:  Some items on the QRS Short_Name may be logically skipped per the instrument instructions. Only one of the 2 oxygen saturation scales (RSTESTCD = "NEWS102" or "NEWS103") is completed for each subject. The other will be treated as a logically skipped item. In addition, item RSTESTCD = "NEWS104A" is only completed when the response to RSTESTCD = "NEWS104" is the amount of oxygen received (in L/min). A record is created in rs.xpt for all items. When an item is considered a logically skipped item, it is represented as follows:

   1. RSSTAT = "NOT DONE".       

   2. RSREASND = "LOGICALLY SKIPPED ITEM".
      

   3. RSORRES, RSSTRESC, and RSSTRESN are set to null (missing).

6. This language is currently under development. For --ORRES items which are otherwise missing...

7. Include this point if score(s) are submitted to SDTM. Update blue text: The QRS Short_Name instrument includes a total score (and other scores as needed.  If so, change "that is" to "that are") that is considered as captured data on the CRF and is 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 [Insert copyright holder's name or other source.].

   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.

8. This language is currently under review. Evaluator information is only to be included when the information is collected directly on the CRF. instruments will no longer be using QSEVAL/QSEVALID; however RSEVAL/RSEVALID and FTEVAL/FTEVALID will continue to be used on Clinical Classifications and Functional Tests. Language for Clinical Classifications and Functional tests follows; language for instruments is currently under review. Remove this point if it does not apply.

   For Clinical Classifications and Functional Tests (only when collected on the CRF):  *** This section to be updated.  QSEVAL/ID, FTEVAL/ID, and RSEVAL/ID will no longer be used.  Supplemental qualifiers will represent this information. *** For QRS Short_Name, the evaluator is defined as the (the appropriate term from controlled terminology). Alternatively, if only evaluator name or initials could be collected: For QRS Short_Name, sponsors should follow their internal data management procedures on representing the name or initials of the evaluator. CDISC Controlled Terminology is available for Evaluator (e.g., --EVAL = "HEALTH CARE PROFESSIONAL") and Medical Evaluator (e.g., --EVALID = "RATER 1"). To reiterate, only include this point if the evaluator/administrator is collected directly on the CRF.

9. Include this point if there are comments at the end of the instrument. Remove this point if it does not apply.: Comments located at the end of the QRS Short_Name will be recorded in the Comments domain (CO). All assumptions and business rules described in the SDTMIG CO domain are applicable.

10. Include this point if there are responses over 200 characters. Remove this point if it does not apply: Some responses to the QRS Short_Name items exceeded the 200-character limit for the QSORRES variable and needed to be reduced to fewer than 200 characters. Section 4, SDTM Mapping Strategy, indicates which item responses were revised in order to fit the 200-character limit.
    

11. Terminology

    1. QSCAT, QSTESTCD, and QSTEST (and other variables such as QSORRESU as needed) values are included in CDISC Controlled Terminology.

    2. A full list of value sets for the qualifier, timing, result, and unit fields is provided in Section 4, SDTM Mapping Strategy. (Note: Only the result field is always used. Include qualifier, timing, and unit fields as needed and remove this note.)

3.2 Example for the QRS Short_Name QS Domain Model

The QRS Short_Name example below shows the terminology used to implement the instrument in the QS domain. This example shows the data for 1 subject collected at the baseline visit for the QRS Short_Name instrument. The example uses CDISC Controlled Terminology for QSTESTCD, QSTEST, and QSCAT. All original results are represented with preferred terminology in QSORRES. This result is then transformed into the standard numeric score in QSSTRESN and a character representation of the standard numeric score in QSSTRESC.

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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 QS domain. It also provides guidance on how the result variables (QSORRES, QSSTRESC, and QSSTRESN) should be populated.

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