SUDI data request
for the Ministry of Health
NZ Mortality Review Data Group
2016
Methodology
Mortality data
The data for this report are from the Mortality Review Database. The data were extracted from the database on 12 October 2016. The age range for this report is 0 days to less than one year. In all tables, the year of death relates to the calendar year in which the individual died, rather than the year the death was registered. This is different to some other official collections, where the year the death is registered is used. DHB is assigned using the DHB of residence, rather than the DHB in which the death occurred. The deaths of non-New Zealand residents are excluded from the report.
Case selection
For deaths in infants less than one year of age, ‘SUDI’ (Sudden Unexpected Death in Infancy) was assigned as the cause of death where any one of the following ICD-10-AM codes were listed as the underlying cause of death in the Mortality Collection:
R95 Sudden infant death syndrome;
R96 Other sudden death, cause unknown;
R98 Unattended death;
R99 Other ill-defined and unspecified causes of mortality;
W75 Accidental suffocation and strangulation in bed;
W78 Inhalation of gastric contents;
W79 Inhalation and ingestion of food causing obstruction of respiratory tract.
In addition, from mid-2006 onwards, Perinatal Society of Australia & New Zealand (PSANZ) coding, as ascribed by the PMMRC and recorded in the Mortality Review Database, was available for neonatal cases (0-27 days). For neonatal deaths that did not have an ICD-10 code in the SUDI range (as described above) where PSANZ coding was available, the following Neonatal Death Classification codes (and their sub-codes) were used to select cases:
7.1 Sudden Infant Death Syndrome;
7.31 Accidental trauma;
7.91 Unclassified sudden infant death.
Cases were further individually reviewed to ensure only SUDI deaths were included. If cases had a PSANZ code and history consistent with SUDI they were included, regardless of the ICD-10 code that had been ascribed.
Ethnicity
There are multiple sources of ethnicity data in the database. These are: Births, Deaths and Marriages, the Ministry of Health, Coronial records and the information entered by co-ordinators when reviewing a death. These data sources are prioritised based on evidence as to their quality and completeness in New Zealand.
DHB of Residence
The DHB of residence is derived from the person’s address as supplied by the coroner, police or BDM. This is based on the individual’s self-identified ‘usual’ place of residence, and does not necessarily reflect their legal residential status.
Statistics
The data presented in this report were computed from the database by the NZ Mortality Review Data Group. Cell values are not supplied when these are less than three.
The denominator used in this analysis is the number of live births in New Zealand, as supplied by the Ministry of Health. The year of registration of death is used, rather than the year the death occurred. Rates in this report are presented as per thousand live births.Rates are not calculated for numbers less than three.
SUDI mortality
Table 1SUDI mortality (number of deaths and rate per 1000 live births), New Zealand 2015
Number of deaths / Rate per 1000 live birthsNew Zealand / 44 / 0.71
Source: Numerator Mortality Review Database; Denominator Ministry of Health live births 2015
Table 2SUDI mortality (number of deaths and rate per 1000 live births), by DHB of residence and ethnicity, 2011-2015 combined
DHB of residence / Māori / Non-Māori / TotalDeaths / Rate / 95% CI / Deaths / Rate / 95% CI / Deaths / Rate / 95% CI
Northland / 9 / 1.32 / 0.61-2.51 / <3 / s / - / <12 / 0.98 / 0.49-1.75
Waitemata / 3 / 0.41 / 0.09-1.21 / 3 / 0.09 / 0.02-0.27 / 6 / 0.15 / 0.06-0.33
Auckland / <3 / s / - / 8 / 0.29 / 0.13-0.58 / <11 / 0.32 / 0.15-0.58
Counties Manukau / 27 / 2.38 / 1.57-3.46 / 18 / 0.58 / 0.34-0.92 / 45 / 1.06 / 0.78-1.42
Waikato / 19 / 1.76 / 1.06-2.75 / 7 / 0.43 / 0.17-0.88 / 26 / 0.96 / 0.63-1.41
Lakes / 9 / 2.09 / 0.96-3.97 / 4 / 1.25 / 0.34-3.2 / 13 / 1.73 / 0.92-2.96
Bay of Plenty / 10 / 1.51 / 0.72-2.78 / <3 / s / - / <13 / 0.83 / 0.43-1.46
Tairawhiti / 7 / 2.79 / 1.12-5.74 / 0 / - / - / 7 / 1.94 / 0.78-4.00
Hawke's Bay / 7 / 1.34 / 0.54-2.75 / <3 / s / - / <10 / 0.81 / 0.37-1.54
Taranaki / 5 / 1.91 / 0.62-4.45 / 3 / 0.58 / 0.12-1.69 / 8 / 1.02 / 0.44-2.02
MidCentral / 6 / 1.46 / 0.54-3.18 / 0 / - / - / 6 / 0.55 / 0.20-1.19
Whanganui / 6 / 3.04 / 1.12-6.62 / 0 / - / - / 6 / 1.42 / 0.52-3.10
Capital & Coast / 7 / 1.87 / 0.75-3.85 / 4 / 0.27 / 0.07-0.69 / 11 / 0.59 / 0.30-1.06
Hutt / 4 / 1.36 / 0.37-3.47 / 5 / 0.72 / 0.23-1.68 / 9 / 0.91 / 0.42-1.73
Wairarapa / 0 / - / - / <3 / s / - / <3 / s / -
Nelson Marlborough / 3 / 1.72 / 0.35-5.01 / <3 / s / - / <6 / 0.65 / 0.21-1.52
West Coast / <3 / s / - / 0 / - / - / <3 / s / -
Canterbury / 6 / 1.12 / 0.41-2.43 / 15 / 0.60 / 0.33-0.98 / 21 / 0.69 / 0.43-1.05
South Canterbury / 0 / - / - / 0 / - / - / 0 / - / -
Southern / 8 / 2.20 / 0.95-4.33 / 7 / 0.50 / 0.2-1.02 / 15 / 0.85 / 0.47-1.40
New Zealand / 139 / 1.59 / 1.33-1.86 / 83 / 0.38 / 0.31-0.48 / 222 / 0.73 / 0.64-0.83
‘s’ indicates rate not calculated due to small numbers
Source: Numerator Mortality Review Database; Denominator NZHIS Live Births 2011–2015
1
McDonald G, Healey M. NZMRDG, University of Otago. 14.11.2016