An Indication of New Zealanders’ Health 2007
Public Health Intelligence
Monitoring Report No. 16
Ministry of Health. 2007. An Indication of New Zealanders’ Health 2007. Wellington: Ministry of Health.
Published in October 2007 by the
Ministry of Health
PO Box 5013, Wellington, New Zealand
ISBN 978-0-478-31234-8 (print)
ISBN 978-0-478-31235-5 (online)
HP 4488
This document is available on the Ministry of Health’s website:
Authors
The authors of this report are Jane Wang (Advisor, Epidemiology), Miranda Devlin (Advisor, Statistics), Li-Chia Yeh (Advisor, Statistics) and Erin Holmes (Advisor, Epidemiology) of Public Health Intelligence (PHI), Ministry of Health.
Acknowledgements
The authors are grateful to Craig Wright (Senior Advisor, Statistics/Epidemiology, PHI) for providing advice and support, to Jinny Gunston (Advisor, GeoHealth, PHI) for creating the map, and to Ken Huang (Advisor, Statistics, PHI) for statistical support. The authors also gratefully acknowledge the constructive comments made by Niki Stefanogiannis (Senior Advisor, Public Health Medicine, PHI).
The report was peer reviewed by Gary Jackson, Counties Manukau District Health Board, and Stephen Salzano, Ministry of Health. The authors wish to thank the reviewers for providing valuable comments and suggestions.
An Indication of New Zealanders’ Health 20071
An Indication of New Zealanders’ Health 20071
Contents
Authors
Acknowledgements
Introduction
Structure of the report
Indicators selection
Data Sources and Methods
Data sources
Notation for years
Codes for disease classification
Breakdown of indicators
Statistical methods
Methods refinement
How to interpret results
National Highlights
Population demography
Socioeconomic factors
Health outcomes and risk/protective factors
Population Demography
New Zealand Indicators
District Health Board (DHB) Indicators
Glossary
References and Further Readings
Appendices
Appendix 1: PHIOnline −
Appendix 2: ICD–10–AM Codes Used in this Report
Appendix 3: WHO Standard Population
List of Tables
Table 1:Data sources
Table 2:Population demography, New Zealand, 2006 Census usual residents – prioritised ethnicity
Table 3:Population demography, New Zealand, 2006 Census usual residents – total response ethnicity
Table 4:Socioeconomic indicators, age-standardised rates, New Zealand
Table 5:Health outcome and risk/protective factor indicators, age-standardised rates (unless otherwise noted), New Zealand
Table 6:Socioeconomic indicators, age-standardised rates, by DHB – North region
Table 7:Socioeconomic indicators, age-standardised rates, by DHB – Midland region
Table 8:Socioeconomic indicators, age-standardised rates, by DHB – Central region
Table 9:Socioeconomic indicators, age-standardised rates, by DHB – South region
Table 10:Health outcome and risk/protective factor indicators, age-standardised rates (unless otherwise noted), by DHB – North region
Table 11:Health outcome and risk/protective factor indicators, age-standardised rates (unless otherwise noted), by DHB – Midland region
Table 12:Health outcome and risk/protective factor indicators, age-standardised rates (unless otherwise noted), by DHB – Central region
Table 13:Health outcome and risk/protective factor indicators, age-standardised rates (unless otherwise noted), by DHB – South region
Table 14:Socioeconomic indicators, age-standardised rate ratios, by DHB – North region
Table 15:Socioeconomic indicators, age-standardised rate ratios, by DHB – Midland region
Table 16:Socioeconomic indicators, age-standardised rate ratios, by DHB – Central region
Table 17:Socioeconomic indicators, age-standardised rate ratios, by DHB – South region
Table 18:Health outcome and risk/protective factor indicators, age-standardised rate ratios (unless otherwise noted), by DHB – North region
Table 19:Health outcome and risk/protective factor indicators, age-standardised rate ratios (unless otherwise noted), by DHB – Midland region
Table 20:Health outcome and risk/protective factor indicators, age-standardised rate ratios (unless otherwise noted), by DHB – Central region
Table 21:Health outcome and risk/protective factor indicators, age-standardised rate ratios (unless otherwise noted), by DHB – South region
List of Maps
Map 1:Population distribution, 2006 Census, counts, by DHB
An Indication of New Zealanders’ Health 20071
Introduction
An Indication of New Zealanders’ Health 2007 is the latest report in a series monitoring the health of the New Zealand population produced by Public Health Intelligence, the epidemiology group of the Ministry of Health.
The report has been developed to provide an easy-to-use collection of health dataon key issues affecting the health status of New Zealanders. It provides a reference for national and regional policy makers and service planers to identify health issues of importance and to measure the outcomes of interventions. The information may also be used by interested groups to raise additional detailed questions regarding specific health issues. In view of this, detailed descriptions and analyses of patterns or cause-and-effect relationships have been excluded from this report.
Information in this publication will be updated on an annual basis. Trend analyses are intended to be published with future updates.
Structure of the report
The information presented in this report contains demographics, socioeconomic indicators, and health outcome and risk/protective factors for New Zealand and District Health Board (DHB) regions. Data are presented mainly in table form. A brief summary that highlights the key national results precedes the statistical information. Data presented in this report are in the following order:
- Population demography, New Zealand, counts
- Population distribution, by DHB, counts
- Socioeconomic indicators, New Zealand, rates
- Health outcome and risk/protective factor indicators, New Zealand, rates
- Socioeconomic indicators, by DHB, rates
- Health outcome and risk/protective factor indicators, by DHB, rates
- Socioeconomic indicators, by DHB, rate ratios
- Health outcome and risk/protective factor indicators, by DHB, rate ratios.
Data for the 21 DHBs are presented within four larger geographical regions as follows:
- North region: Northland, Waitemata, Auckland and Counties Manukau DHBs
- Midland region: Waikato, Bay of Plenty, Tairawhiti, Lakes and Taranaki DHBs
- Central region: Hawke’s Bay, Whanganui, MidCentral, HuttValley, Capital & Coast and Wairarapa DHBs
- South region: Nelson Marlborough, Canterbury, West Coast, South Canterbury, Otago and Southland DHBs.
Indicators selection
The report features 71 different health and health-related indicators that highlight some of the key health issues for New Zealanders. The indicators were chosen because they:
- address the New Zealand Health Strategy priority population health objectives.
- focus on salient health issues.
- are reliable and validly monitored.
- are responsive to change.
The 13 priority population health objectives identified in The New Zealand Health Strategy (Minister of Health 2000) are:
- reducing smoking
- improving nutrition
- reducing obesity
- increasing the level of physical activity
- reducing the rate of suicides and suicide attempts
- minimising harm caused by alcohol and illicit and other drug use to both individuals and the community
- reducing the incidence and impact of cancer
- reducing the incidence and impact of cardiovascular disease
- reducing the incidence and impact of diabetes
- improving oral health
- reducing violence in interpersonal relationships, families, schools and communities
- improving the health status of people with severe mental illness
- ensuring access to appropriate child health care services including well child and family health care and immunisation.
In addition to the above priorities, selected indicators that summarise health outcomes are presented. Indicators that specifically address infectious disease are also provided in this report. In future versions, information on environmental health are expected to be included.
To promote accessibility, data provided in this report will also be available through PHIOnline (http//: PHIOnline is a multidimensional data visualisation website consisting of an interactive map linked to tables and charts of data. Detailed information on PHIOnline is provided in Appendix 1. It is intended that future versions of the publication will be presented through PHIOnline.
Data Sources and Methods
Data sources
Data presented in this report are collated from multiple sources. Table 1 below lists the data sources used for the indicators.
Table 1:Data sources
Data source / Indicator / YearStatistics New Zealand
2006 Census / Demography, socioeconomic (excluding household crowding), smoking prevalence for adults aged 15+ years / 2006
2001 Census / Household crowding / 2001
New Zealand Health Information Service (NZHIS)
Mortality collection dataset
National Minimum Dataset (NMDS)
New Zealand Cancer Registry / Mortality
Hospitalisations (public)
Cancer registrations / 2002−03
2004−05
2003–04
Institute of Environmental Science and Research Limited (ESR) / Infectious disease notifications / 2004–05
2002/03 New Zealand Health Survey (NZHS) / Risk and protective factors (eg, nutrition, physical activity, alcohol drinking, high blood pressure etc), disease prevalence / 2002/03
Action on Smoking and Health (ASH) Year 10 Survey 2005 / Smoking prevalence for youth / 2005
New Zealand Tobacco Use Survey (NZTUS) / Smoking prevalence for adults aged 15−64 years / 2006
New Zealand Mental Health Survey / Any serious mental disorders, suicide attempt, substance use disorders / 2003/04
Royal New Zealand Plunket Society (Inc) / Breastfeeding / 2005
School Dental Service / Caries-free teeth, and decayed, missing or filled teeth / 2004
National Childhood Immunisation Coverage Survey / Immunisation coverage / 2005
This report updates data presented in the previous version of 2006 (Ministry of Health 2006a). However, data extracted from the 2002/03 New Zealand Health Survey are still reported here as the new 2006/07 New Zealand Health Survey data will not be available until 2008.
For administrative data (sourced from NZHIS and ESR), the most recent two years of data are aggregated to provide more stable rate estimates.
From the 2006 Census, ‘total response’ has been introduced by Statistics New Zealand for ethnicity classification. ‘Total response’ records all ethnicity responses and results can exceed the total population if people have reported more than one ethnicity. This classification recognises people with multiple ethnicity identifications. ‘Prioritisation’ classification, which was applied prior to the 2006 Census and is still used in this report, assigns the ethnicity of a person who has given multiple responses to just one ethnicity. The priority rule is: Māori>Pacific>Asian>European/Other. A person belonging to both Māori and European ethnic groups, for example, would be classified as Māori. ‘Unknown’ ethnicity has been included in the ‘Other’ ethnic group. This process ensures that the total number of responses equals the total population. To inform readers, ethnic information in the demographic section is provided using both ‘total response’ and ‘prioritisation’ classification methods.
The 2002/03 New Zealand Health Survey (NZHS) assessed a sample from the New Zealand adult population aged 15 years and over living in permanent private dwellings. Data were collected through face-to-face interviews and a total sample size of 12,929 was achieved. As the survey was designed to provide national results, DHB level results were estimated based on the small area estimation method. A description of the methodology can be acquired from 2002/03 New Zealand Health Survey: DHB snapshot datacube help documentation (Public Health Intelligence 2004).
The target population of the 2006 New Zealand Tobacco Use Survey (NZTUS) was New Zealand adults aged 15–64 years and living in permanent private dwellings. Data were collected through computer assisted face-to-face interviews, with a total sample size of 5,703. The survey was designed to produce estimates that represent the New Zealand population. Estimates at DHB level are currently not available.
The Action on Smoking and Health (ASH) Year 10 Smoking Survey is a school– based annual national survey, and targets year 10 students aged 14–15 years. Data are collected by means of a self–administered questionnaire. The 2005 survey had a sample size of 32,927.
Te Rau Hinengaro: The New Zealand Mental Health Survey was sampled from people aged 16 and over living in permanent private dwellings throughout New Zealand during 2003/04. The total number of the survey sample was 12,992. As the survey design was for a nationally representative sample, data are not available at DHB level. Instead, rates are provided for four large geographical regions. Rates extracted for this report are for 12-month prevalence (that is, events that occurred in the past 12months).
Data from the School Dental Service cover children at school Year 8 (Form 2), who had been examined by the DHB School Dental Service at the time of data collection. Data are provided for both fluoridated and non-fluoridated areas. Ethnic breakdown is available for Māori, Pacific peoples (Pacific) and European/Other (including Asian). Data are not available for a gender breakdown. There is variation in collecting and reporting practices between DHBs, therefore any comparison of DHBs should proceed with caution.
The Royal New Zealand Plunket Society enrols approximately 90 percent of the new baby population in New Zealand and collects breastfeeding data. Data are available for Māori, Pacific and European/Other (including Asian), but no data are available for a gender breakdown. Maori and Pacific mothers may be under–represented in this sample.
The target population of The National Childhood Immunisation Coverage Surveywas the New Zealand population of children aged 2 and 3 years old living in permanent private dwellings. Data were collected through face-to-face interviews with the principle caregiver of the child surveyed. Medical records were used to confirm the child’s vaccination history (with the caregiver’s consent). The survey had a sample size of 1,563.
Notation for years
Three notations are used in this report to denote the years of data presented, for example, 2004–05, 2003/04 and 2005. The first denotes two full calendar years of data, pooled to estimate rates. The second denotes survey data collected during 2003 and 2004. The third denotes one full calendar year.
Codes for disease classification
The International Classification of Diseases, tenth revision (ICD-10–AM) has been used to code diseases/conditions for reporting mortality, hospitalisations and cancer registrations. For the ICD-10–AM codes used, please refer to Appendix 2.
Breakdown of indicators
Ethnicity
The data are subgrouped into Māori, Pacific, Asian and European/Other ethnic groups, where possible. European/Other includes European and other ethnicities not counted in the Māori, Pacific and Asian categories. In cases where data for Asian were not available as a separated group, data have been stratified by Māori, Pacific and European/Other, where European/Other includes European and other ethnicities not counted in the Māori and Pacific categories. The classification of ethnic group, when calculating the rates, used the ‘prioritisation’ rather than ‘total response’ method. Details for the two methods are given in the earlier paragraph.
Sex
Data are stratified by sex for the total New Zealand population, where possible. A ‘total’ figure (males and females combined) is also provided.
Age
In the demographic section for national data, life-cycle age groupings are presented as follows:
- Infant and children0–14 years
- Youth15–24 years
- Adults25–64 years
- Older adults65+ years
Indicators in this report are in most cases presented for all ages in the population. For some cases, however, indicators are presented for a specific age group, and the relevant age group is noted in the table.
Statistical methods
Rates are calculated as the proportion of the population associated with the indicator compared to the population of interest. Rates are expressed per 100 (percent), per 1000 or per 100,000.
The denominators used for calculating the rates derived from administrative data are the interpolated Census population for the same year as the numerator year. The interpolated Census population are population estimates based on a linear interpolation between Census years.[1]
Age-standardised rates are frequently used in this report. This enables a valid comparison between populations with different age structures. Rates are age-standardised using the World Health Organization standard population (WHO 2000), see Appendix 3. Age-specific rates are presented for indicators relating to a defined age group. Several indicators are presented with crude rates (that is, no adjustment has been made). Where an age-specific or crude rate is used, a note is provided beside the indicator; otherwise all rates presented are age-standardised. Please note that crude rates cannot be compared between population groups with different age distributions.
To quantify the difference between the rates of each DHB and the total for New Zealand, rate ratiosare provided. A rate ratio (RR) in this report is the ratio of the rate in the DHB compared to that in New Zealand. Rate ratios are presented as either age-standardised RRs or age-specific RRs. A RR higher than 1 implies that the rate exceeds the New Zealand average, whereas a RR less than 1 implies that the rate is below the national average. The following paragraph gives further explanation of this.
Ninety-five percent confidence intervals(95% CIs) are presented for both rates and rate ratios, where possible. The confidence intervals give an indication of the margin of error. When the 95% CIs of two rates do not overlap, the difference in rates between the groups is statistically significant with 95% confidence. If the two confidence intervals do overlap, the difference could be due to chance, and is not statistically significant. With rate ratios, if the 95% CIs of a rate ratio does not include 1, the two rates are said to be statistically significantly different from each other. For example, a rate ratio of 1.5 with 95% CIs of 1.2–1.8 means that the rate is 1.5 times higher in the particular DHB than the New Zealand average with 95% confidence. Larger DHBs and more common diseases or determinants usually have narrow confidence intervals and so have a greater likelihood of achieving a statistically significant difference than smaller DHBs and less common diseases or determinants.