New Zealand adults who used cannabis for recreational purposes in the past year

Unadjusted results: reflect the actual percentage (or mean) for the specified population in each time period. It is important to note that differences in the population structure may explain some of the variations between DHBs.
Age-standardised rates: take into account different age structures in the underlying populations of each DHB.

All results presented in this data are weighted so that they are representative of the total population of adults 15+ and children aged 0–14 years (or a smaller subset where specified).
The dataset includes unadjusted prevalence figures for most indicators, estimated number of people, and 95% confidence intervals.
Indicators are provided by age group, sex, ethnic group (total response ethnicity, ie where people who belong to more than one ethnic group are counted once in each of the ethnic groups they identify with) and neighbourhood deprivation (area-based measure of socioeconomic position or deprivation).

Sample sizes for small regions are not sufficient to produce reliable estimates for single years. However, reliable regional level statistics can be produced by pooling annual data to improve the range and statistical quality of analyses that can be undertaken at that level. Pooling annual NZHS data sets can also improve the statistical precision of estimates for Māori and ethnic minorities (including Pacific and Asian ethnic groups).

In the current study, estimates were produced by pooling the most recent NZHS datasets - 2017/18, 2018/19, and 2019/20. For the purpose of comparing the results over time, pooled 3-year datasets were created by combining 2014/15, 2015/16, 2016/17 and 2011/12, 2012/13 and 2013/14.

On 19 March 2020 the interviewing for the New Zealand Health Survey was suspended to reduce any risks of transmitting COVID-19 between interviewers and respondents. The 2019/20 Annual Explorer does not include any data collected since the COVID-19 Alert System was introduced by the Government in March 2020 to manage and minimise the risk of COVID-19 in New Zealand. It therefore does not include any information about people's health during the pandemic. The survey results for the 2019/20 New Zealand Health Survey are based on the data collected in the first three quarters of the year only. No adjustments or imputations have been done to account for the impact this has had on the 2019/20 data. This results in reduced sample sizes and in some cases, lower precision of the estimates but this is less noticeable when the 2019-20 results are combined with 2018-19 and 2017-18. The majority of the adult and child indicators are not subject to any seasonal variation, and so are not impacted by the loss of data from one quarter of data collection. The following indicators did show seasonal variation, and hence users should be more cautious about interpreting movements between previous years and 2019/20.

The data provider uses 95% confidence intervals to indicate the uncertainty in an estimate due to collecting data from only a sample of the population.
Even with pooling three years of data, the sample size for some of the smaller DHBs remains relatively small.

The survey results are likely to underestimate or overestimate some indicators due to the nature of self-reported information. For example, many of the survey results assume that the respondents could accurately recall previous events (such as a diagnosis by a doctor). Also, many indicators are about diagnosed conditions, and not everyone with a particular condition will have had it diagnosed by a doctor. The amount of error will vary from indicator to indicator, depending on a number of factors, including the respondent’s age. Respondents may also over-report good behaviours or under-report risk behaviours based on what they consider to be socially desirable.

Some indicators (body size and raised blood pressure) are based on actual measurements taken by the surveyors rather than self-reported information. These results are more reliable than self-reported information because the surveyors apply consistent measurement techniques to all respondents using standardised measuring tools.

This survey presents a snapshot of the health of New Zealand adults and children at one point in time. The survey can be used to look at associations between different factors, such as health status and neighbourhood deprivation. However, we cannot conclude that the survey results show cause-and-effect relationships between these factors, in part because we do not know which factor occurred first. For example, if the survey finds that a particular condition is more common in people living in deprived areas, an association has been identified. This association does not necessarily mean the condition is caused by living in deprived areas.

Not included in the survey were: people living in institutions (such as for long-term hospital care, hospital- and dementia-level care in aged-care facilities, and in prisons), the homeless, short-term visitors and tourists.

At URL provided, select the 'Download datasets' tab, and download the 'District Health Board prevalence and mean data' CSV file.

This data presents the 2017–20 regional results from the New Zealand Health Survey, for both adults and children.

The New Zealand Health Survey (NZHS) conducts face-to-face interviews with over 13,000 adults and the parents/ caregivers of over 4000 children annually. The 2017-2020 pooled data contains about 37,100 adult respondents and 12,500 children. The survey results refer to the usually resident population of all ages living in permanent dwellings, aged-care facilities and student accommodation