Identification of data quality issues
As part of the Ministry’s quality assurance processes, we work with the survey provider to monitor interviewer performance. These checks help identify and address any anomalies in the way interviewers ask survey questions and record respondent answers.
While preparing the 2024/25 survey data for release, checks identified that some responses for a small number of interviewers were very different from the rest of the sample. This issue was also present in the 2023/24 data that was published in November 2024.
How we corrected the data
The error was corrected by removing the affected responses from the data. That is, responses for a small number of questionnaire items were changed to “Don’t know”, for 274 adults and 170 children. Changes were made only to the following topics of the questionnaire.
Adults:
- GP – barriers to access (questions: A2.360, A2.33a, A2.35a)
- Getting help for mental health and substance use concerns (question: AMH1.07a)
Children:
- GP – barriers to access (question: C2.270)
- Sleep (question: C3.13b)
- Household food security (questions: CFS1.01 – CFS1.08)
- Dietary habits (questions: C3.06a – C3.08a)
Survey statistics for indicators that are derived from these questions may have changed as a result. National level prevalences have not changed outside the confidence intervals of the previously published statistics. Statistics for Pacific peoples, NZDep quintile 5, and the Northern health region have experienced the largest revisions. However, the revisions have not changed the interpretation of findings or the narrative.
Affected release
The corrections affect one release – the 2023/24 New Zealand Health Survey results published in November 2024. The corrected data is available as part of the 2024/25 annual release now available at:
- Annual Update of Key Results 2024/25: New Zealand Health Survey
- Annual Data Explorer. This online tool includes more recent statistics, as well as the updated 2024/25 statistics.
Impact on statistics
The corrections affect a small number of indicators, and the majority of changes are with the margin of error for the previously published statistic.
The following table shows the impact of the corrections on a selection of population groups in the 2023/24 New Zealand Health Survey.
Indicator | Group | Published | Revised | |||
|---|---|---|---|---|---|---|
Percent (%) | 95% CI | Percent (%) | 95% CI | Change (percent- | ||
Adults | ||||||
| Consulted family, whānau and/or friends about mental health in past 12 months | Total New Zealand | 16.7 | 15.6–17.8 | 16.0 | 14.9–17.2 | -0.7 |
| Pacific people | 22.1 | 17.6–27.3 | 22.6 | 18.0–27.7 | 0.4 | |
| NZ Deprivation Index - quintile 5 | 18.2 | 15.3–21.4 | 16.6 | 14.1–19.3 | -1.6 | |
| Health region - Northern | Te Tai Tokerau | 16.9 | 14.6–19.6 | 15.2 | 13.1–17.4 | -1.7 | |
| Unmet need for GP due to cost in the past 12 months | Total New Zealand | 15.5 | 14.4 - 16.6 | 15.1 | 14.1 - 16.2 | -0.4 |
| Pacific | 22.3 | 18.1 - 26.9 | 20.1 | 16.0 - 24.6 | -2.2 | |
| NZ Deprivation Index - quintile 5 | 17.8 | 15.3 - 20.5 | 16.5 | 14.2 - 19.0 | -1.3 | |
| Health region - Northern | Te Tai Tokerau | 18.0 | 15.8 - 20.3 | 16.8 | 14.7 - 19.1 | -1.2 | |
| Unmet need for a GP due to wait time being too long in the past 12 months | Total New Zealand | 25.7 | 24.1–27.3 | 24.8 | 23.4–26.3 | -0.9 |
| Pacific people | 38.1 | 30.7–46.0 | 30.0 | 24.9–35.4 | -8.2 | |
| NZ Deprivation Index - quintile 5 | 30.2 | 26.8–33.7 | 27.0 | 24.8–29.2 | -3.2 | |
| Health region - Northern | Te Tai Tokerau | 31.3 | 28.3–34.4 | 28.8 | 26.3–31.5 | -2.5 | |
| Unfilled prescription due to cost in past 12 months | Total New Zealand | 4.4 | 3.9–4.9 | 3.9 | 3.5–4.4 | -0.5 |
| Pacific people | 9.1 | 6.4–12.5 | 5.5 | 3.7–7.8 | -3.6 | |
| NZ Deprivation Index - quintile 5 | 8.4 | 6.9–10.1 | 6.7 | 5.5–8.0 | -1.7 | |
| Health region - Northern | Te Tai Tokerau | 6.1 | 4.9–7.4 | 4.8 | 3.9–5.8 | -1.3 | |
Children | ||||||
| Usually sleeps less than recommended in a 24 hour period (0-14 years) | Total New Zealand | 23.7 | 21.1–26.4 | 21.7 | 19.3–24.1 | -2.0 |
| Pacific people | 41.1 | 34.7–47.8 | 33.0 | 27.3–39.1 | -8.1 | |
| NZ Deprivation Index - quintile 5 | 36.5 | 31.0–42.3 | 29.1 | 24.6–34.1 | -7.4 | |
| Health region - Northern | Te Tai Tokerau | 36.2 | 31.0–41.6 | 31.4 | 26.7–36.4 | -4.8 | |
| Usually meets sleep duration recommendations in a 24 hour period (0-14 years) | Total New Zealand | 71.9 | 69.2–74.5 | 73.7 | 71.2–76.1 | 1.8 |
| Pacific people | 53.8 | 46.9–60.6 | 61.4 | 55.3–67.2 | 7.6 | |
| NZ Deprivation Index - quintile 5 | 59.0 | 53.5–64.4 | 65.9 | 61.1–70.4 | 6.9 | |
| Health region - Northern | Te Tai Tokerau | 61.6 | 56.1–66.8 | 66.0 | 61.0–70.8 | 4.4 | |
| Unmet need for a GP due to wait time being too long in the past 12 months (0-14 years) | Total New Zealand | 18.5 | 16.4–20.8 | 16.6 | 14.9–18.4 | -1.9 |
| Pacific people | 26.5 | 19.7–34.2 | 17.5 | 12.5–23.3 | -9.0 | |
| NZ Deprivation Index - quintile 5 | 22.7 | 17.5–28.6 | 15.4 | 12.2–19.2 | -7.3 | |
| Health region - Northern | Te Tai Tokerau | 27.6 | 23.7–31.7 | 22.3 | 19.3–25.6 | -5.4 | |
| Children living in households where food runs out often or sometimes in past year (0-14 years) | Total New Zealand | 27.0 | 24.4–29.7 | 24.9 | 22.5–27.4 | -2.1 |
| Pacific people | 54.8 | 48.0–61.5 | 49.4 | 42.0–56.8 | -5.5 | |
| NZ Deprivation Index - quintile 5 | 46.9 | 41.7–52.3 | 41.3 | 36.1–46.7 | -5.6 | |
| Health region - Northern | Te Tai Tokerau | 33.7 | 28.6–39.2 | 28.2 | 23.5–33.3 | -5.5 | |
| Children living in households that eat less because of lack of money often or sometimes in past year (0-14 years) | Total New Zealand | 26.1 | 23.9–28.5 | 24.4 | 22.3–26.5 | -1.7 |
| Pacific people | 53.0 | 47.3–58.6 | 48.5 | 41.8–55.2 | -4.5 | |
| NZ Deprivation Index - quintile 5 | 44.9 | 39.9–50.0 | 39.8 | 35.1–44.6 | -5.1 | |
| Health region - Northern | Te Tai Tokerau | 32.9 | 28.1–37.9 | 27.8 | 23.7–32.3 | -5.1 | |
Enquiries
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