Professor of Epidemiology and Health Data Science
We are developing and using novel methods to create ‘household units of analysis’, and linking these to other sources of data for research into the wider determinants of population health.
Researchers have been analysing health and household circumstances for several years, for example to study the effects of overcrowding and multi-generational living on the risk of catching Covid-19. To date, the methods for linking people into households using health records have not been well described. We have developed standardised, open-source methods for creating household units of analysis, and are using these methods for research into population health, health inequalities and the wider determinants of health.
In 2021 we published ‘ASSIGN’, a validated, open-source algorithm that matches Unique Property Reference Numbers (UPRNs) to the patient addresses in health records. UPRNs are unique identifiers for every addressable location in Great Britain and there is a government expectation that they are included in all public sector datasets. In pseudonymised form, they can be used to link health record data with other information related to a patient’s residential address, such as the floor area or number of rooms. It can also be used to determine which people live together at a point in time to estimate household overcrowding. We use encrypted UPRNs for research, so patient identities and addresses remain hidden, while analysts can build a rich picture of the factors that affect health at a population scale. More about ASSIGN.
In 2024 we published a standardised method for creating household units of analysis from primary care health records. This comprises a set of rules that uses ASSIGN and health records to group occupants of the same household, either at a fixed or variable point in time. The logic is reproducible in other coding environments, and our publication notes any biases in the resulting household groupings, which means researchers using the method are aware of any implications in their analyses. We are using the method, and linkage to publicly-available Energy Performance Certificate register data (which includes property size and number of rooms), to study:
In collaboration with Swansea University, University of Edinburgh and Endeavour Health Charitable Trust, we are using household analysis methods to develop a definition for ‘adverse household environments’. We plan to analyse what impact living in these circumstances as a child may have on future health, and specifically understand how household mobility influences the health of its members. The Healthy Households project will compare findings for the ethnically diverse and predominantly urban North East London population with the predominantly White and more rural Welsh population. This will enable new methods for characterising households by social, economic, environmental, educational and health factors to better understand the wider determinants of health.
Without understanding the methods for keeping addresses and identities hidden, it is reasonable for the public to assume that addresses used in research are identifiable. This can lead to concerns about privacy. Existing resources to facilitate public debate about patient data are focused on health data and do not specifically consider addresses, so we developed our own.
As part of Healthy Households, we worked with Alison Thomson, a designer and Senior Lecturer in Patient and Public Involvement, to develop and test a set of materials for public workshops. The materials include interactive, tactile objects to help researchers describe:
The materials were developed by multidisciplinary researchers and refined with input from two workshops with 23 members of the public in the London borough of Tower Hamlets. The final resources are intended for a broad and diverse audience and are available to support ethical research practices and deliberative engagement activities across Britain.
We are coinvestigators in the Tower Hamlets HDRC. This is an initiative funded through the National Institute for Health and Care Research (NIHR) to boost research capacity and evidence-based decision-making within local government. As part of the collaboration, we are using encrypted UPRNs to link health and council data in two exemplar projects: Evaluating the impact of the primary school universal free school meals policy in Tower Hamlets and other London councils, and analysing inequalities in council housing conditions.
In collaboration with Swansea University (led by Professors Rich Fry and Lucy Griffiths), University of Edinburgh (led by Professor Chris Dibben), Endeavour Health Charitable Trust (David Stables) and Paul Simon.
Our household unit methods and research are supported by ADR UK (Administrative Data Research UK) Economic and Social Research Council investment (part of UK Research and Innovation) - View the abstract on UKRI website; Barts Charity; HDRUK; and the NIHR Health Determinants Research Collaboration in Tower Hamlets. Dr Gill Harper was supported by a UKRI HDRUK Ernest Rutherford Fellowship.
We are grateful to the Discovery Programme Board, general practitioners and patients for permission to use routinely collected health data for research.