Data Platform

ASSET is a data platform, initially formed by linking nine New Zealand administrative and health databases together (three study population databases linked to six outcome databases (see Figure 1)). ASSET data platform is an enduring data asset, with biennial re-linkage for the most up-to-date information and enabling the inclusion of additional databases. ASSET offers the potential for multiple inquiries in population-based health services research in kidney disease – with the focus of equity in access to health services for New Zealanders with kidney failure.

What is ASSET?

Watch our conference presentation to learn more about our ASSET data platform!

Linking 9 New Zealand health databases


Figure 1: Initially linking nine separate New Zealand administrative and health databases together to create the ASSET platform

What is ASSET?

ASSET is a rich data platform and comprehensive resource for population health services research. Each database relates to a specific illness and/or health service, providing a snapshot of individuals’ health and health services use. By combining these databases, the health care journey of individuals across multiple health services can be examined. For example, the cancer registry records diagnoses of cancer over time. Linking the cancer registry to the National Non-Admitted Patient Collection Data & National Minimum Dataset means that it is possible to compare the length of hospital stay, or the number of admissions for those with cancer versus those without.

ASSET’s Data Sources

ASSET’s linked databases contain health data on people with kidney failure and living kidney donors and their engagement with the health care system including hospitalisations, emergency and outpatient services, cancer diagnoses, mental health service use, medication use, and deaths and their causes.


Australia and New Zealand Dialysis and Transplant Registry records data on all persons receiving dialysis and those who undergo transplantation within Australia and New Zealand between 1980 – 2019. ASSET includes only those persons living in New Zealand.


NZ Blood Service:

New Zealand Blood Service Database records all persons in New Zealand waitlisted for a kidney transplant (living or deceased) and waitlist status changes over time, including temporarily inactive or permanently inactive between 2005 – 2019.


National Minimum Dataset:

collects and records health service use including private and public hospital discharge information from inpatients and day patients from 1988 to 2019.



Programme for the Integration of Mental Health Data collects and records baseline health service use for mental health conditions in New Zealand between 2008 – 2019.



Australia and New Zealand Living Kidney Donor Registry records data on all living donors in Australia and New Zealand between 2004 – 2019. Only living donors in New Zealand are included in ASSET. 


National Non-Admitted Patient Collection Data:

 collects and records health service use data including non-admitted patient outpatient and emergency department events from 2006 – 2019.


Cancer Registry:

collects and records data on all cancer diagnoses in New Zealand between 1995 – 2019.


Pharmaceutical Claims Database:

 records active and past medication between 1996 – 2019 in New Zealand.


Mortality Collection Database:

 records all deaths and their causes using International Classification of Diseases (ICD) between 1988 – 2018 in New Zealand.

Figure 2: Calendar years of available data included in the ASSET study from each data source. ASSET cohort 2006 – 2019 defined in red outline.

Ensuring Privacy and Security

Maintaining privacy and security of individual health information is essential to research. Data linkage was completed by the New Zealand Ministry of Health. Data collections at the New Zealand Ministry of Health are governed by privacy and data protection legislation including the Health Information Privacy Code 2020, The Privacy Act 2020 and The Health Information Governance Guidelines. Once linked, all databases were de-identified before sending to researchers via password protected files.

ASSET data platform contains no identifiable information; therefore, the privacy of individuals is fully protected. ASSET data is stored on a university secured server and is unable to be accessed unless approval is granted by the ASSET steering committee and University Ethics committee.

Data Linkage

ASSET data linkage was performed by the New Zealand Ministry of Health and privacy and security was maintained throughout. The New Zealand Ministry of Health used patients’ National Health Index (NHI) numbers to deterministically link between existing registry and administrative health databases in New Zealand (Figure 1). Those missing NHI numbers were linked probabilistically (Figure 2). Once linkage was completed, the data was de-identified and sent via password protected files to ASSET researchers.

Figure 3: Example of deterministic linking database ANZDATA with Mortality Collection database. Deterministic linkage is possible when data sets contain a common identifier – NHI number

Want to get involved?

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