Care Redesign

Uniquely Identified: The Impact of a National Health Index

Article · October 4, 2017

The debate around a U.S. unique health identifier has resurfaced recently. There have been petitions (MyHealthID), competitions (CHIME), and numerous blogs and articles on the relative merits and issues associated with a national health identifier. I choose not to rehash old arguments (“the privacy! the cost! the ethics!”) but instead offer a perspective from a clinician, researcher, and consumer of health services in a health system with a mature, entrenched national health identifier: New Zealand.

For context, when I say New Zealand (NZ), think “Colorado with the VA for all.” We have around 4.7 million people living in around 100, 000 square miles, whereby residents receive comprehensive health care funded primarily by government. Since around 1990, all New Zealanders have been assigned a National Health Index (NHI), or given one at birth. Currently, approximately 95% of the population have a valid and active NHI. This uniquely identifying 7-character alphanumeric follows us through our health life, cradle to grave, as we journey through and across the health sector, consistent through changes of region, name or spelling thereof, or doctor. Our unique NHI is utilized in the community (general practitioner, pharmacist, laboratories), by secondary and tertiary-based specialists, at acute care and elective hospitals, at emergency departments and urgent care facilities, by screening programs, and in the public health arena (immunization, child health, school dental services). There is timely and routine integration of the NHI with a number of clinical databases, including the National Medical Warning System. An encrypted version of the NHI is employed in health and disability databases and registers.

NZ has had a form of an NHI since the late 1970s, and a fully-implemented centralized system since 1992. This early adoption likely reflects a number of factors. First, as noted above, we are small in population and well-defined geographically. That is, it was achievable. Second, traditionally New Zealanders are eager and willing to try new initiatives and tools; the country is popular as a testing ground for global companies trialling new technologies. Finally, the population has sufficient belief in the benefits of integrated data, and in the ability of the broader system to keep personal information private. This is a critical factor, as confidentiality concerns are potentially more relevant in NZ than elsewhere. Kiwis are highly connected (only 4 degrees of separation for us); it is not uncommon to discover that the person who served your coffee that morning is dating your neighbor. (This is not a joke. I once met a Canadian at a conference in Boston who was moving to Vancouver into an apartment about to be vacated by a New Zealander. The conversation went like this. Her: “You won’t know him.” Me: “Try me.” Her: “He’s an orthopedic surgeon called X.” Me: “I went to his wedding.”)

Back to the NHI. What does the NHI mean to me as a clinician, a researcher, and a health care consumer?

As a clinician the NHI may seem to offer little theoretical benefit to the individual physician; within your given health system, you presumably know your patients and have their accurate health information readily available. However, in practice, this perfect relationship rarely occurs. That is, the patient may be new to you or has visited out-of-network health providers; information may be unavailable, confusing, or conflicting. In this situation, what the NHI gives me is invaluable — safety and reassurance in clinical practice. The accurate identification of an individual and their health providers allows practitioners to provide sounder, more thoughtful, and more confident care.

However, clinically, the real beauty of the NHI is seen if we consider a broader population of patients and their overall well-being. One example: in NZ, we have a national Mobile Surgical Unit. It travels around the country, doing routine low-risk elective procedures (e.g., pediatric tooth extraction, insertion of tympanostomy tubes) in areas that are geographically isolated. Using the combination of the NHI and our National Immunisation Register, we can identify the under-immunized children from any part of country who are scheduled to have a procedure on this bus, and offer them vaccination while under anaesthesia during this visit. It is the perfect example of the health system working together to improve population well-being.

As a researcher Information from patients attending all hospitals in the country has been collected in a national database for more than 20 years, all available at the individual level with an encrypted NHI as the identifier (conditional on ethical approval). In some regions, data from the community (including social services, pharmacy, primary, and ambulatory care providers) has also been merged to allow planners of health services to see the patient journeys of their entire population. However, now our “big” (NZ-level big) data has grown even bigger. Statistics New Zealand has recently developed a vast repository of linkable datasets from nearly 50 national surveys/registers, including those inside and outside the health system: the Integrated Data Infrastructure. Researchers can examine the intersection of social services (including welfare and benefits, child protective services), employment, interaction with the judicial and correction systems, travel and migration, income and tax, and education information across multiple generations. Using the NHI to enumerate a population, we are able to ask nuanced health questions with the incorporation of this social data. We are only at the beginning of our understanding of the potential of this dataset.

As a consumer Here is another immunization example (which reflects the haze of raising multiple small children). In 2011, Christchurch — a city in the South Island of the country — had a major earthquake (6.3 on the Richter scale). The next day, residents were encouraged to leave town if possible, and we as a family packed up what we could carry and went north. In all of this mayhem, my twins needed their vaccines. Anyone who has premature twins living in a house with two dogs and two preschoolers knows that this is the one intervention that you do not delay and do not skip. So that week, in a different town and with no records or health cards or any documentation, I was able to go the general practitioner at the bottom of the road where they could find my babies’ records through their NHI, see what vaccines they needed, provide the immunizations, and update the National Immunisation Register with a record of this service. They also added in my temporary address and contact details, and alerted my Christchurch doctor of this intervention.

However, like the clinician example, the real benefit of the NHI to the consumer is seen when you extrapolate my experience to a larger group. This is easy to do, as we were not the only family dispossessed that week. There were thousands of us, driving and flying throughout the country, looking for a safe haven while the city adjusted. The NHI allowed uninterrupted and safe health care for a population, irrespective of their location or access to documentation. It truly is an underrated resource of national importance.

Writing this, I live in California. The sunshine and the enthusiasm are infectious, and the health IT start-ups exciting and boggling in their innovation. Currently, the U.S. has almost full adoption of a certified electronic health record (EHR) in acute care hospitals, and ambulatory care providers are not far behind. This last year, I have been exploring the role of the EHR and health IT in health care quality in the U.S., including its use to reduce low-value care and racial/ethnic disparities in quality, and its ability to facilitate individualized ratings of quality. Visits I made to leading innovators in predictive analytics such as Pieces Technologies in Dallas and the Center for Health Data Innovations at Montefiore Medical Center beautifully illustrated the blue sky benefits of the substantial investment made by the U.S. into the EHR over the last decade.

And here is the rub. New Zealand has the NHI, but not yet a national EHR, and we cannot yet capitalize on all of the potential of the NHI without this platform. However, the U.S. has made this investment already — you have done the heavy lifting. There is both the EHR infrastructure and the enthusiasm of the health sector and its consumers for digital tools and health IT. Put plainly, in this area, the U.S. of A. could simply soar. The country is uniquely poised — you’ve built the roads, you’ve invented the cars, all you need is free-flowing gas. By adding in an NHI, the potential for connected, synergistic care for the U.S. population, and for nuanced, leading-edge research, is unprecedented.


Funding/Support: Support for this research was made possible by a Harkness Fellowship in Healthcare Policy and Practice, awarded by The Commonwealth Fund.

Role of the Funder/Sponsor: The Commonwealth Fund had no role in the preparation, review, or approval of the manuscript or decision to submit the manuscript for publication.

Acknowledgements to Prof. Tony Blakely for his review of this article.

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