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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 published articles describing the instrument as well as input from PASI instrument subject-matter experts (SMEs). 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 PASI FREDRIKSSON 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 industry. This supplement uses the Fredriksson article as the stand for responses with some slight modifications from SME from SME input. The PASI FREDRIKSSON divides the body into 4 sections (i.e., head, 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"). Instead of "striking" and "exceptionally striking" that are referenced in the Fredriksson article, "severe" and "very severe" were used due to SME input suggesting these responses are used more frequently. For the PASI FREDRIKSSON, RSORRES is populated with the text description; the numeric rating is represented in the standardized character and numeric result variables RSSTRESC and RSSTRESN.

   1. CDISC created a CRF based on the Fredriksson article using the symptom terms "erythema/redness," , "thickness/induration," , and "desquamation/scaling." . Per subject-matter expert recommendationsSME recommendations, desquamation was included with scaling even though desquamation is not referenced in the Fredriksson 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 involvement"). For the area, RSORRES is populated with the text description; the numeric rating is represented in the standardized character and numeric result variables RSSTRESC and RSSTRESN.
   

3. The PASI FREDRIKSSON 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 Fredriksson 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, that reason is represented in RSREASND (e.g., RSREASND = "REFUSED"). If the reason is unknown, 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.

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