Part of SUS+ essentials Secondary Uses Service user guide
Net and bulk submission methods
A CDS messages carries information that determines the update mechanism to be used to apply the new data to SUS. The two available submission methods are:
BULK update
When using the ‘BULK Update’ submission method, all records within a specified time period are replaced for that sender, for that period.
NET change
When using ‘NET Change’ submission method, only new records, or records where details have changed, are submitted. This includes deleting records that have been sent incorrectly using a NET Delete CDS.
NET change submission method is more efficient and more reliable. This is because it reduces both the load on the system and the likelihood of creating data quality issues such as accidental duplicates or deletions.
Current submission method use
Currently, 30 percent of submissions to SUS use Net submission method. Amongst the remaining 70 percent, some systems are capable of producing extracts of new records together with only those records that have changed over a given period. Where a single data source is used for CDS this would directly enable NET submission by those organisations.
It is understood that many of those not in a position to submit using NET update deal with multiple source data sets and have technical problems to resolve to isolate records for inclusion in submissions
More information about Net and Bulk submission methods can be found in the Submitting CDS Data to SUS guidance document on the SUS Guidance .
When producing the CDS message, Bulk submitters must ensure the CDS REPORT PERIOD START DATE is entered correctly. Historically, data senders have inadvertently deleted data over a number of years by populating this data item incorrectly.
Where possible, bulk update submitters are encouraged to automate the completion of CDS REPORT PERIOD START DATE and End dates as part of the construction of each submission.
CDS type and net change
Net submitters need to be aware of the impact that CDS type has on Net Change submission method. Most CDS types can only be overwritten by the same CDS type. However, there are some exceptions to this general rule. This table shows what CDS type can be overwritten by which other CDS type.
Please note that interchanges that contain only unfinished (CDS 170, 180, 190, 200) episodes, this change will only be visible for records when using the SEM view. This is because such an interchange does not contain any records eligible for PbR processing.
Example
A data sender has mistakenly assigned a CDS Type of 120 (Finished Birth Episode (APC)) as CDS Type 130 (Finished General Episode (APC)) and submitted it to SUS. To change the CDS Type to 120, the user cannot change the record and submit the record again (see table). Instead the same CDS Type 130 record should be sent to SUS with a Net Update Type of ‘1‘(delete). Once the record is removed from SUS, it can be changed to CDS Type 120 and resubmitted to SUS as a Net Update Type ‘9’ (new) CDS Type 120 record.
Using NET submission method can help prevent data duplication of records in SUS.
Mixing bulk and net interchanges
Mixing Bulk and Net interchanges can lead to unintended loss of data. If Net and Bulk submissions are mixed, Bulk will update all records in SUS, for the CDS SENDER IDENTITY, report start and end date combinations, irrespective of extract dates, applicable dates or original submission method for that Bulk replacement group.
Example 1
A user sends 10,000 records as CDS Type 130 (Finished General Episode (APC)). The user then sends 500 records further records for the same period as CDS Type 140 (Finished Delivery Episode (APC)) using Bulk submission method under the same CDS SENDER IDENTITY, Report Start and End Dates. Because CDS Types 130 and 140 are part of the same Bulk Replacement Group (BRG 010) the second submission overwrites all of the first submission; leaving 500 records as opposed to the 10,500 APC records.
It is possible to send a Bulk interchange with many records with the same CDS UNIQUE IDENTIFIER for the same send A Net submission will replace all records containing a corresponding CDS UNIQUE IDENTIFIER for the sender, providing that the CDS APPLICABLE DATE is later than or equal to the extract date. If all records in a bulk interchange have the same CDS UNIQUE IDENTIFIER and a subsequent Net change deletion record is submitted with the same CDS UNIQUE IDENTIFIER, all the Bulk records will be deleted.
Example 2
A user sends 10,000 records using the Bulk protocol with CDS UNIQUE IDENTIFIER equal to '99999999' for all records (because it is not part of a Bulk Update submission and not used as a key field). The user then sends one single record under the same CDS SENDER IDENTITY where CDS UNIQUE IDENTIFIER is equal to '99999999' using Net submission. This single record in the second submission overwrites all the records from the first Bulk submission, leaving a single record, rather than 10,001.
These examples highlight the two main risks of mixing Bulk and Net.
SUS validates Applicable Date against Extract Date when Net records update Bulk records, but does not check Applicable Date when applying a Bulk update to a Net change
- a Bulk interchange will delete all Net records irrespective of applicable date
- if a Bulk interchange has not used a CDS UNIQUE IDENTIFIER then multiple records can be replaced by a single Net record
Records sent as Net cannot be used to replace Bulk records that do not contain a CDS UNIQUE IDENTIFIER. Attempting a Net update of existing Bulk records in this way would effectively result in duplicate records being submitted.
Last edited: 16 January 2023 4:22 pm