Methodology for Understanding health and healthcare module of the New Zealand Health Survey

About the New Zealand Health Survey

The New Zealand Health Survey is a population-based health survey commissioned by the New Zealand Ministry of Health. The survey includes a core set of questions and measurements that are repeated every year and a series of modules that change each year. In 2017/18, the survey included a module called 'Understanding health and healthcare' for people aged 15 years or older. For more information about the 2017/18 New Zealand Health Survey see the Methodology Report and Questionnaires and Content Guide.

How the HLQ was selected for the survey

A number of instruments have been developed to measure people's understanding of health and healthcare. The HLQ was selected for use in the New Zealand Health Survey following a review of instruments, advice from an expert advisory group, and other factors including criteria for survey modules (eg, duration, complexity) and partial alignment with the Ministry's Health Literacy Framework.

The HLQ is a multi-dimensional tool that collects information on how people find, understand and use health information, and how people manage their health and interact with healthcare providers. The complete HLQ has nine domains and 44 items, but this was considered too long for a module. In consultation with stakeholders, three domains were removed leaving six domains (30 items).

How people were selected for the survey

The survey has a multi-stage sampling design that involves randomly selecting a sample of small geographic areas, households within the selected areas, and individuals within the selected households. One adult aged 15 years or older and one child aged 14 years or younger (if any in the household) were chosen at random from each selected household.

Survey respondents are selected from the 'usually resident' population of all ages living in private dwellings, aged-care facilities and student accommodation (99% of the eligible population). For practical reasons, the survey did not include people living in institutions (such as long-term hospital care, hospital- and dementia-level care in aged-care facilities and prisons), the homeless, short-term visitors and tourists.

How was data collected

Data for the 2017/18 New Zealand Health Survey was collected by a specialist survey provider (CBG Health Research) in the respondents’ home. Most data was collected via computer assisted personal interviewing (CAPI). This is a face-to-face or in-person research method whereby a trained interviewer uses software on a tablet or laptop computer to ask questions and record responses. Data for sensitive topics, including the 'Understanding health and healthcare module', was collected via computer assisted self-interviewing (CASI). This meant that respondents were given the tablet to complete the module by themselves.

How many people took part in the survey

A total of 13,869 people aged 15 years or older took part in the 2017/18 New Zealand Health Survey, which was 80% of those invited. Of these, 13,562 (97.8%) took part in the 'Understanding health and healthcare' module and 13,155 (94.9%) answered all 30 of the HLQ items. 307 respondents (2.2%) skipped the entire module, with 288 (2.1%) doing so because they needed language assistance. The proportion of respondents skipping the module because they needed language assistance varied by ethnic group: Asian (13.9%), Pacific (7.1%), Māori (0.3%) and European/Other (0.3%).

How the HLQ was scored

The complete HLQ has nine domains, each of which has four to six items (44 items in total). The first five domains ask respondents to indicate their level of agreement with a list of statements. There are four response options (strongly disagree; disagree; agree; strongly agree), which are scored 1 to 4. The remaining four domains ask respondents to report their capability at doing a list of tasks. These items have five response options (cannot do/always difficult; usually difficult; sometimes difficult; usually easy; always easy), which are scored 1 to 5.

For each domain, a mean score is calculated by averaging scores across all items in that domain (provided that respondents answered at least half of the items in that domain). The number of respondents with domain scores ranged from 13,501 for domain ‘9. Understand health information well enough to know what to do’ to 13,557 for domain ‘2. Having sufficient information to manage my health, which represents 95–98% of the full sample. In population surveys, mean scores are grouped into three categories as below.

Domain	Score	Category
1. Feeling understood and supported by healthcare providers	1 to <2.5 2.5 to <3.5 3.5 to 4	Disagree/strongly disagree Agree Strongly agree
2. Having sufficient information to manage my health
3. Actively managing my health
4. Social support for health
5. Appraisal of health information
6. Ability to actively engage with healthcare providers	1 to <3.5 3.5 to <4.5 4.5 to 5	Difficult* Usually easy Always easy
7. Navigating the healthcare system
8. Ability to find good health information
9. Understand health information well enough to know what to do

Note: The six domains in bold were included in the 2017/18 New Zealand Health Survey

* Includes ‘Cannot do or always difficult’, ‘Usually difficult’ and ‘Sometimes difficult’

How ethnicity is classified in the survey

The survey uses the total response classification of ethnicity. This means that people who reported more than one ethnic group are counted once in each group they reported. Results are output for the following four ethnic groups: Māori, Pacific, Asian and European/Other.

Neighbourhood deprivation

Neighbourhood deprivation refers to the New Zealand Index of Deprivation 2013 (NZDep2013). The NZDep2013 measures the level of relative socioeconomic deprivation for each neighbourhood according to a combination of the following 2013 Census variables: household income, benefit receipt, transport (access to car), household crowding, home ownership, employment status, qualifications, support (sole-parent families) and access to the internet. Results are output for quintiles of neighbourhood deprivation: quintile 1 represents the 20 percent of areas with the lowest levels of deprivation and quintile 5 represents the 20 percent of areas with the highest level of deprivation.