Longitudinal research in Aotearoa New Zealand using the Integrated Data Infrastructure: a review

The Integrated Data Infrastructure (IDI) is a collection of deidentified whole population administrative datasets, linked at the individual level, and made available through Stats NZ for 'public good' research. This paper reviews longitudinal research that has been undertaken using the IDI, and highlights the strengths, weaknesses, opportunities, and threats of using the IDI for longitudinal research. It is argued that the IDI can and has been used for longitudinal research that would be difficult or impossible to undertake without a resource such as the IDI, including longitudinal research involving small, sometimes marginalised populations, research involving intergenerational research and quasi-experimental family designs, and research investigating residential variations in the natural environment. However, issues regarding ethical governance need addressing. Researchers wishing to use the IDI should familiarise themselves with its limitations, particularly around what service use data capture and what this represents, what is missed by assessing only deficit-focused data, and the variable quality of the data.