Page History

...

Further information about the ASSIGN CVD 10-YEAR RISK can be found in the following article: Woodward M, Brindle P, Tunstall-Pedoe H, for the SIGN group on risk estimation. Adding social deprivation and family history to cardiovascular risk assessment: the ASSIGN score from the Scottish Heart Health Extended Cohort (SHHEC). Heart 2007; 93: 172-176.

3 The RS Domain Model

3.1 Assumptions for

...

Disease Response and Clin Classification Domain Model

All assumptions and business rules described in the SDTMIG RS SDTMIG RS domain are applicable to this supplement.  Additional assumptions specific to the APACHE II are the ASSIGN Cardiovascular Disease 10-Year Risk Score (ASSIGN CVD 10-YEAR RISK) are listed below.

The QRS APACHE II is a severity-of-disease classification system that uses a point score based on the initial values of 12 routine physiologic measurements, age, and previous health status. Scores range from 0 to 71 and higher scores correspond to more severe disease and a higher risk of death. The composite score is based on findings represented in other SDTM domains such as Laboratory Test Results (LB) and Vital Signs (VS).

1. The APACHE II provides weightings for 12 physiology measures, the sum of which yields a total acute physiology score (APS). This weighting system for 11 of the physiology measures is based on a numeric rating scale (0-4) where 0 reflects values within the normal range and an increase in the numeric rating scale represents an increase in the abnormality of the physiology measure in either the high or low direction.

   1. For example, the rating of 4 for heart rate (ventricular response) may coincide with multiple definitions depending on whether the abnormality is in the high or low direction (e.g., 4 = ">=180" or 4 = "<=39", respectively).

   2. Note that the score for the Glasgow Coma Score (GCS), the final physiology measure, is the reverse; lower scores indicate mild or no head injury and higher scores represent more severe head injury.

   3. Age and severe chronic health problems reflect diminished physiologic reserve; these have been directly incorporated into APACHE II. Chronological age is a well-documented risk factor for death from acute illness that is independent of severity of disease. This item includes a numeric rating (0, 2, 3, 5, 6) and a definition of what is represented by the rating (e.g., 6 = ">=75" years in age).

   4. Severe chronic organ system insufficiency or immunocompromised state markedly influenced outcome. Nonoperative and emergency surgery admissions had a substantially higher risk for death from prior chronic conditions than did elective surgical admissions. This indicates that patients with the most severe chronic conditions are not considered to be candidates for elective surgery. For patients with a history of severe organ system insufficiency or who are immunocompromised, a numeric rating of 2 or 5 is assigned for chronic health points, where 2 is assigned “for elective postoperative patients” and 5 is assigned “for nonoperative or emergency postoperative patients”.

   5. For the APACHE II, RSORRES is populated with the text description; the numeric rating is represented in the standardized character and numeric result variables RSSTRESC and RSSTRESN.

2. Records are created in rs.xpt (or in split rsap.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 = "PREFER NOT TO ANSWER"). If the reason is unknown, then RSSTAT = "NOT DONE" and RSREASND is missing.

3. Some items on the QRS APACHE II may be not done due to conditional branching per the instrument instructions. 

   1. The equation for computing the alveolar-arterial O₂ gradient is heavily dependent on inspired O₂ levels, so there are 2 methods for calculating oxygenation. When inspired O₂ levels ≥ 0.5 use the alveolar-arterial O₂ gradient and complete RSTESTCD = "APCH105A". When inspired O₂ levels < 0.5 use the partial pressure of oxygen (PaO₂) and complete RSTESTCD = "APCH105B". The other will be treated as not done due to conditional branching.

   2. In addition, arterial pH (RSTESTCD = "APCH106A") is preferred but in cases where oxygenation is normal and blood gases are not measured, serum HCO₃ (RSTESTCD = "APCH106B") can be substituted. Only 1 of these 2 physiological parameters will be measured and the other will be treated as not done due to conditional branching. 

   3. In addition, a chronic health response, item RSTESTCD = "APCH115", is only assigned (along with the points) when the patient has a history of severe organ system insufficiency or is immunocompromised. Otherwise it will be not done due to conditional branching.

   4. A record is created in rs.xpt for all items. When an item is considered conditionally branched, it is represented as follows:

      1. RSSTAT = "NOT DONE"       

      2. RSDRVFL = "Y" (the record is derived as a "NOT DONE" record)
         

      3. QNAM = “RSCBRFL”, QLABEL = “Conditional Branched Item Indicator “, QVAL = “Y” (RS supplemental qualifier variable)

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

4. The APACHE II instrument includes a total APS and total APACHE II score which are considered as captured data on the CRF and 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 on the CRF. If scores are received by the sponsor,

   1. It is recommended that they are submitted to SDTM and verified in ADaM.

5. Terminology

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

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

3.2 Example for the QRS APACHE II RS Domain Model

The rsap.xpt dataset represents the items from the APACHE II. The RS domain was split into 2 physically separate datasets: the APACHE II instrument (rsap.xpt) and the GCS (rsgc.xpt). Each dataset represents a subset of the RS domain. Note: In this example, the vital sign and lab values used to answer the APACHE II items were also collected and represented separately in the VS and LB domains. RSLNKID is used to link the APACHE II records to their corresponding findings in their respective source domains. This relationship is defined in the RELREC table.

The APACHE II example below shows the terminology used to implement the instrument in the RS domain. This example shows the data for 2 subjects collected at visit 1 for the APACHE II instrument. The example uses CDISC Controlled Terminology for RSTESTCD, RSTEST, RSCAT, and RSORRESU.  All original results, matching the CRF item response text, are represented in RSORRES. This result is then represented as a standard numeric score in RSSTRESN and as a standard character representation in RSSTRESC

The table represents the items from the APACHE II instrument.

ASSIGN Cardiovascular Disease 10-Year Risk Score (ASSIGN CVD 10-YEAR RISK) describes the cardiovascular risk of the subject.  The score is expressed as a percentage. 

• The ASSIGN Cardiovascular Disease 10-Year Risk Score is derived via an algorithm that includes labs, vital signs, medical history, substance use, social deprivation and demography. Please refer to Appendix 1 of the reference cited above for the algorithm calculation.  This is considered captured data and not a derivation.
• Social deprivation is represented with the Scottish Index of Multiple Deprivation (SIMD) and comes from a database which uses the postal code of the subject. The SIMD is collected and used to calculate the ASSIGN, however is considered to be a possible privacy issue.  Therefore it is not submitted and is not represented in the example below. 
• The clinical classification evaluator should be stored in RS.
• Terminology:
  1. RSCAT, RSTESTCD and RSTEST are approved CDISC controlled terminology.

3.2 Example for the RS Domain Model

The ASSIGN CVD 10-YEAR RISK Score example below shows the terminology used to implement this clinical classification measure in the RS domain.  This example shows data collected for the ASSIGN CVD 10-YEAR RISK Score for two subjects, one has only one visit and the other has two visits. The example uses CDISC controlled terminology for RSTESTCD, RSTEST, and RSCAT as well as SCTESTCD and SCTEST for SIMD.  Data that is used for input to the composite scores such as labs, vital signs, substance use, social deprivation and medical history are included in its original domain and the relationship to the RS domain should be defined using the RELREC domain.  The ASSIGN CVD 10-YEAR RISK is represented in the RS domain and is linked to the other domains in RELREC by the RSLNKID.

The following dataset represents source-data GCS scores which were input into the APACHE II. Note that RSSEQ is set to start at 101 for each subject within this split RS domain as APACHE II is only collected once during the study (at VISITNUM=1). RSGRPID in the split domain below matches RSGRPID for the corresponding record in the preceding RS domain example.

...