The VHIN has several catalyst projects underway to demonstrate how New Zealand’s health data can be used for health research.


Getting the denominator right

Having a reliable population denominator is necessary for analysing health and social data. However, the most common sources of population denominators – the annual mid-year national population estimates provided by Statistics New Zealand, or health service utilisation (or ‘health contact’) populations constructed with Ministry of Health datasets – have their limitations. We are using the Integrated Data Infrastructure (IDI) to develop a more complete and accurate population denominator, based on anonymised information about individuals’ activities from health, tax, education, injury claims, births and visa datasets. These health and non-health datasets provide relatively comprehensive information across all ages.

We are currently constructing an IDI-population for Census night 2013, in order to make comparisons with the existing denominator populations, and demonstrate the utility of an IDI-based denominator for the analysis of health and social data. Once complete, the IDI population denominator will be used as a national cohort to explore social, demographic and geographic variations in cardiovascular disease service utilisation and outcomes.

Host: University of Auckland

Contact: Prof Rod Jackson, email 

Environmental risk factors for congenital malformations

Around 2,500 infants are diagnosed with congenital malformations in New Zealand each year, and congenital malformations account for more than 20% of all infant deaths. However, the modifiable risk factors for congenital malformations have not been previously studied in New Zealand. To examine this we have selected 3,000 infants with congenital malformations (cases) and 3,000 controls through the New Zealand Birth Defects Monitoring Programme. Interviews were conducted with 600 case mothers and 600 control mothers as part of an HRC-funded study. Information on the remainder of cases and controls will be obtained through linkage with health and social sector data in Statistics New Zealand’s Integrated Data Infrastructure. The major aim of the study is to identify modifiable risk factors for congenital malformations. This may include occupational exposures, pharmaceutical use, smoking, and others. If successful the study will also demonstrate the feasibility of using record linkage as a low-cost infrastructure for the continuous monitoring of risk factors for congenital malformations in New Zealand.

Host: Massey University

Contact: Prof Jeroen Douwes, email

Cost of cardiovascular disease in New Zealand

Cardiovascular disease is a leading cause of death and illness in New Zealand. It is responsible for around 13% of health loss in New Zealand and is a particularly important contributor to health loss for Maori. It is also expensive, with the World Bank estimating that CVD costs for developed countries range between 1% and 3% of GDP. However, there is very little detailed information about the costs of CVD in New Zealand, and how these vary with time, age, ethnicity and specific diagnosis. The aim of this project is to estimate the total public health system costs of cardiovascular disease in New Zealand by time before and after CVD diagnosis. The project uses the established “excess” or “net” costing method, which estimates the excess health costs for individuals with CVD over and above the standard health costs for individuals without CVD. The project makes use of individual-level cost and diagnosis information available in New Zealand’s national health collections, and will develop methods for calculating these costs within the Integrated Data Infrastructure environment.

Host: University of Otago

Contact: Dr Andrea Teng, email 

The sponsors of these catalyst projects were University of Auckland, Massey University and University of Otago, with support in-kind from the Ministry of Health.