Annual Report
Purpose: To verify and update information on the National Health Index and to compile mortality statistics.
Year commenced: 2009
Features: Data transferred monthly on CD.
BDM disclosure to MoH: BDM provides full names (including names at birth), address, occupation, ethnicity and gender, date and place of birth, date and place of death, and cause(s) of death.
2011/12 activity:
| Records received for matching | 29,981 |
| Possible matches identified | 26,368 |
| Records manually matched | 3,502 |
| New NHIs allocated | 111 |
| Corrections to matches (including from previous years matches) | 22 |
Commentary: After completing the authorised matching, MoH retains for a year the full data received to help, when needed, with matching coroner's reports to the Mortality register. As this is a breach of the time limits specified in the Privacy Act 1993 we have suggested that if MoH can adequately justify retaining this information it should apply for a s.102 exemption authorising this retention. MoH disagrees with our interpretation. In our view the practical risk is that MoH will make decisions based upon information that was believed to be accurate when supplied but which may since have been corrected by DIA.
Compliance: Not compliant.
Technical information
| Information matching provision | Births, Deaths, Marriages and Relationships Registration Act 1995, s.78A |
| Year authorised/commenced | 2009/2009 |
| Programme type | Updating data |
| Unique identifiers | Death Registration number, National Health Index Number |
System description
Each month Births, Deaths and Marriages (BDM) provide an encrypted file on CD to the Ministry of Health (MoH). MoH then requests the password and decrypts the file.
Only a subset of the information received is required for matching to the NHI records, so a working file is created for matching. The full records received from BDM are retained for one year to assist in matching coroner's reports to the NHI. Death records that match to a single NHI record are assumed to be correctly matched.
Any death records that return more than one possible match to an NHI record are manually reviewed and matched. This may involve identifying and resolving instances where an individual has more than one NHI record.
Death records that are not matched are manually reviewed, and if no match can be found, an NHI record is created.
All death records that have been matched or have had new NHI records created for them are tagged with the NHI number.
At this stage in the process, the matches have not been verified. They are probably correct, but in any such system a small number of mis-matches is expected. To minimise the risk of people missing scheduled treatments the match results are matched to National Booking Reporting System (NBRS) (for elective surgical procedures) and National Immunisation Register (NIR) databases. Where possible matches to individuals listed on these systems are identified, MoH verifies the match by checking alternate information sources. A separate notification is received for deaths in publicly-funded-hospitals, and this is relied upon as verification for these deaths. For all other deaths, MoH verifies these primarily by checking medical certificates and coroner's notifications.
The matched file is loaded into the Mortality database. Then an extract from the Mortality database of the matched records (excluding any still pending verification) is used to update the NHI database.
This extract is also loaded to the National Collections data set. From there it is available to other databases and systems run by MoH and made available to health provider organisations (for example District Health Boards), with a warning message indicating that only some of the records have been subject to independent verification. This is an important warning because the provider organisation might otherwise use the information to update records it holds without appropriate checking.
Some external users also have direct access to the NHI and may see the date of death on any record they are looking at. MoH is relying upon these people recognising any false data before action is taken.
Those records which where matched to records on the NBRS or NIR databases but were not able to be verified at the time of the deaths file processing, are subsequently followed-up and manually updated in the NHI, and, if required in the Mortality system.
The information received from BDM is retained for 12 months to assist with matching late-received information (e.g. coroner's reports) to NHI records.
Historical activity
NHI updating:
| 25/01/2009-30/06/2009 | 2009/2010 | 2010/2011 | |
| Records received for matching | 13,755 | 28,976 | 29,501 |
| Matched | 12,024 | 25,189 | 26,005 |
| Not matched | 1,668 | 3,653 | 3,307 |
| New NHIs allocated | 63 | 134 | 189 |
| Subsequent corrections | 12 | 30 | 28 |
Stillbirths:
| 25/01/2009-30/06/2009 | 2009/2010 | 2010/2011 | |
| Records received for matching | 165 | 445 | 406 |
| Matched | 87 | 243 | 280 |
| New NHIs allocated | 78 | 202 | 126 |
Look-ups of retained BDM data:
| 25/01/2009-30/06/2009 | 2009/2010 | 2010/2011 | |
| Cause of death check for coroners cases | 96 | 210 | 270 |
| Cause of death check, Dr certified | 1,601 | 3,298 | 3,257 |
| Cause of death given, no Dr certifying | 1,831 | 3,739 | 3,713 |
| Coroner in Certifying Dr field | 298 | 581 | 607 |
| NZ Pharmaco viligance requests | 0 | 159 | 529 |
| Total | 3,827 | 7,884 | 8,380 |
