Background: CSC as LSP is setting about meeting its contractual obligation to Connecting for Health to get TPP to migrate SystmOne to SCT. There is a risk that this will be done in isolation from the rest of the GP domain. Emis is already engaged in migrating its users to EmisWeb. 1 Use of cross mapping tables It is unclear at this stage precisely what SystmOne to SCT’ really means. ‘migrating However, it is assumed that information currently coded in CTV3 will be translated to SCT codes using the CTV3 to SCT cross mapping table available from TRUD just as Emis are assumed to have used / to be using the Read v2 to SCT cross mapping table. 1.1 Safety issue: These cross mapping tables have not been through a clinical safety assurance process. They are known to contain erroneous maps. Erroneous maps can lead to a) the wrong Terms being displayed to the user and b) the wrong codes being placed in the record. This could put patient safety at risk. EmisWeb avoids this through being dual coded (SCT and Read v2). The original Read v2 code and Term are retained and all processing currently continues to depend on Read v2. However safety issues could arise if processing were switched to the SCT codes 1.1.1 Mitigation: After translation the Term Text of the resulting SNOMED code must be displayed and the Original Term Text (i.e. from the original source code) must be preserved and displayed to the user unless it is a lexical exact match to the SCT Term. This would enable the human reader to detect discrepancies and take any necessary remedial action but would not on its own remove the risk from background machine processing 1.1.2 Mitigation: Assure the cross mapping tables as already requested by GPSoC. This would reduce but not eliminate the frequency of erroneous maps and resulting erroneous codes for both human and machine readers 1.1.3 Mitigation: Modify GP2GP guidance on the processing of HL7 translation sets so that a receiving system validates all of the codes that it can against each other. This would only ‘understand’ be a partial mitigation because it would only work in circumstances where the sending system had preserved the original source code and even then, only in those circumstances where the cross mapping table had been changed AFTER the original translation had taken place 2 Preferred terms and synonyms
Background: CSC as LSP is setting about meeting its contractual obligation to Connecting for Health to get TPP to migrate SystmOne to SCT. There is a risk that this will be done in isolation from the rest of the GP domain. Emis is already engaged in migrating its users to EmisWeb. 1 Use of cross mapping tables It is unclear at this stage precisely what ‘migrating SystmOne to SCT’ really means. However, it is assumed that information currently coded in CTV3 will be translated to SCT codes using the CTV3 to SCT cross mapping table available from TRUD just as Emis are assumed to have used / to be using the Read v2 to SCT cross mapping table. 1.1 Safety issue: These cross mapping tables have not been through a clinical safety assurance process. They are known to contain erroneous maps. Erroneous maps can lead to a) the wrong Terms being displayed to the user and b) the wrong codes being placed in the record. This could put patient safety at risk. EmisWeb avoids this through being dual coded (SCT and Read v2). The original Read v2 code and Term are retained and all processing currently continues to depend on Read v2. However safety issues could arise if processing were switched to the SCT codes 1.1.1 Mitigation: After translation the Term Text of the resulting SNOMED code must be displayed and the Original Term Text (i.e. from the original source code) must be preserved and displayed to the user unless it is a lexical exact match to the SCT Term. This would enable the human reader to detect discrepancies and take any necessary remedial action but would not on its own remove the risk from background machine processing 1.1.2 Mitigation: Assure the cross mapping tables as already requested by GPSoC. This would reduce but not eliminate the frequency of erroneous maps and resulting erroneous codes for both human and machine readers 1.1.3 Mitigation: Modify GP2GP guidance on the processing of HL7 translation sets so that a receiving system validates all of the codes that it can ‘understand’ against each other. This would only be a partial mitigation because it would only work in circumstances where the sending system had preserved the original source code and even then, only in those circumstances where the cross mapping table had been changed AFTER the original translation had taken place 2 Preferred terms and synonyms
JGPITC-UKTC-subgroup-report-on-SNOMED-CT-safety-issues_v-0-8.docx