Data safe havens: unique longitudinal data drives healthcare innovation

Data safe havens provides a story from birth to death

In Scotland, healthcare data has been collected and stored persistently for many decades - for as long as 50 years. This data includes routinely collected health records and research collected from cohorts in studies and trials.  The linking of such data presents the health story of an individual from birth to death.

In order to devise this information and distinguish between individuals from one database to another, every person registered with a GP in Scotland is assigned a Community Health Index (CHI). 

The unique chi number links datasets

The adoption of the CHI number - a 10-digit patient identifier unique to Scotland – has proven monumental in Scotland’s capabilities when it comes to using healthcare data for research. The date of birth and gender of the individual are included within the identifier which allows the patient to be identified from a centrally maintained register containing additional personal data such as their address, GP, registration place and, where relevant, date of death.

The analytical power provided by the CHI number is relevant because other patient identifiers, such as the UK-wide NHS number, are often randomly allocated numbers that do not hold any specific meaning and are not always linked consistently with other records. For example, this can become an issue if two individuals with the same name reside at the same address and risks misidentification. Instead, the CHI number makes it easier to authenticate whether an individual within a particular database is actually that person and to ensure an accurate linkage between different datasets across the health sector. This makes the CHI number more deterministic whilst other identifiers can be problematic.

For well over a decade, this CHI number has endorsed the compilation and management of several highly curated databases of longitudinal data going back approximately 40-50 years. There are also significant, ongoing initiatives seeking to link the CHI number to other administrative databases such as education and tax.

Depth and breadth of data can be accessed

The University of Dundee’s Health Informatics Centre (HIC) and fellow local Safe Havens host the nationally curated data for the populations which they cover. They can link this data to clinical data such as laboratory test results, diagnoses, and hospital stays, that is not collected nationally. The data captured within clinical systems hold much more detailed information that is captured at a national level, making it invaluable for many types of research and also for the training of Artificial Intelligence and Machine Learning Algorithms. The HIC offers extensive longitudinal datasets across NHS Tayside and Fife, accounting for approximately 20% of Scotland’s population.