Editorial - National Information Collection: New Zealand’s National Health Index

Welcome to the June edition of Health Care and Informatics Review “National Information Collection: New Zealand’s National Health Index”. The edition, as its title implies, focuses on national health information systems and the New Zealand National Health Index.

New Zealand has an internationally recognised reputation for leadership in national health information systems. A key contributor to this reputation is the fact that New Zealand has had some form of national unique identifier for health since the late 1970s, and a fully specified National Health Index (NHI) system since 1992.

In simplest terms, the NHI is a database containing basic demographic information on individuals indexed to a unique identifier, known as the NHI number. The NHI number can be used to connect individuals across a continuum of care services and has a critical role in facilitating data review.

The NHI is the cornerstone of health information in New Zealand. It is viewed as one of several “anchor applications”: single, national systems that provide a standardised output to support business processes across the health sector.

In “Fourteen Years Young: A Review of the National Health Index in New Zealand”, Ray Delany, Management Consultant, Auckland and former Group Manager of the New Zealand Health Information Service, presents a concise review of the history and current state of the NHI in New Zealand.

Delany both acknowledges the practical issues that have arisen with the NHI and points to some of the significant advantages that the NHI offers. Most critically he highlights that the ability to link and correctly assign data in both practical care and research through the NHI provides the opportunity to “…address the two major challenges facing health care services worldwide: (1) minimising the risk of adverse events and (2) maintaining high quality outcome information on public health interventions.”

Delany completes a very useful, brief evaluation of the NHI, concluding that the New Zealand NHI meets most of the criteria set down by the international standard criteria for unique identifiers for health. He highlights that the gaps that exist are relatively minor, relating to the longevity of the system because of the finite number of identifiers that can be generated, and that there have been massive advances in encryption (and encryption cracking) techniques that were not envisaged when the NHI first came into being.

Poignantly, Delany concludes that, while the NHI is not free from difficulties, overall, the system is conceptually sound and practical difficulties that arise from time to time can be resolved. As such, the New Zealand experience has useful lessons that any country attempting to implement similar systems can benefit from.

In a second contribution to this edition, Ray Delany examines some of the difficulties in creating successful information systems in general, and national health information systems in particular.

“The National Health Information System in New Zealand” is a review paper that appeared in its original form in Health Information Management.^[1] We are delighted to include in our publication an abridged and updated version of that paper.

Delany promotes a multi-dimensional approach as the template for success in health information management, highlighting the need for researchers, clinicians, administrators and educationalists to work together with skilled health information managers to achieve the best outcomes.

The paper includes a review of the existing national information systems and data available in the New Zealand environment, including identification of the gaps, and discussion of the ways in which these data are being used to develop outcome measures.

Delany highlights the many existing data sets which provide very useful sources of data and the robust technology and governance mechanisms that exist to protect individual privacy while allowing highly sophisticated analysis of these data. He concludes with a recommendation that the best use is made of these existing data sources.

The technology for protecting individual privacy, referred to by Delany, is the focus of our third paper “NHI Encryption Methods”, authored by Jayden MacRae, Team Leader, Information Management, Compass Health Limited, Wellington.

In his paper, MacRae considers the various methods of preserving data anonymity when using data for analysis that includes the NHI number.

He provides a useful assessment of the relative security strengths and weaknesses of each encryption method, by considering the ability within each method to:

• secure the data 
• reverse the encryption
• encrypt the data at source
• change the encryption key
• allow use of key management only
• allow set sharing
• where necessary, produce discrete data sets which cannot be matched.

In MacRae’s view, two methods meet the seven criteria used: combination cryptographically encrypted NHI and salted asymmetric cryptographically encrypted NHI.

Our guest editorial this month is from Russell Craig, Acting Chief Advisor, Health Information Strategy & Policy, New Zealand Health Information Service (NZHIS), Ministry of Health, Wellington, New Zealand. Craig highlights that information management capacity is one of the fundamental enablers of the high level of cost-effectiveness of the New Zealand health system when compared to countries such as the UK, Australia, Canada and the US. He promotes a view that the national health information system be regarded as a national asset in need of constant management and investment in order for it to deliver what New Zealanders need of it, both now and in the future.

Footnotes

1. Abridged and updated from its original form which appeared in Health Information Management: Delany R. Evolution, not revolution: measurement and management of health outcomes in New Zealand through efficient use of national information systems. Health Information Management 2004; 32(3&4): 118-125.