2. Can you explain what data linkage is and how you are using it to research health inequalities in pregnancy and improve outcomes for babies?
In summary, data linkage is the process through which two or more independent databases that store an individual’s data, can be linked together and de-identified. This data can then be used for research purposes. More details on data linkage can be found in this video.
This animation was created by a multidisciplinary team at the NIHR Maudsley Biomedical Research Centre (BRC) and illustrates the process of data linkage and the benefits for researchers.
In healthcare specifically, medical records for one person are often on several different electronic systems. These systems are often not integrated and do not talk to each other, which is problematic for both providing care and research purposes. Data linkage research is currently being used within the ARC South London Maternity and Perinatal Mental Health theme, through a programme called the Early Life Cross Linkage in Research (eLIXIR) Partnership.
The eLIXIR Partnership was developed in 2018, generating a repository of real-time, de-identified, structured data derived from the electronic health record systems of two acute NHS Trusts and one Mental Health NHS Trust in south London. Linked maternity, neonatal and maternal mental health records were created to support research into the early life origins of physical and mental health of mothers and children.
Electronic health records provide potentially transformative information for life course research, integrating physical and mental health disorders and outcomes in routine clinical care. The eLIXIR database has over 36,000 pregnancies in its system and will grow by over 14,000 new maternity cases annually. Additionally, the children resulting from these pregnancies will also be followed up. Additional datasets will supplement the current linkage from other local and national resources, including primary care and hospital inpatient data for mothers and their children.
This is the first time that we have been able to follow women and their babies through our health care systems in south London, to look at the impact of the care that they received, and also to examine the impact of pre-existing disease and social inequalities on their outcomes. Read more information about eLIXIR
3. What are the challenges with using data linkage to carry out this type of research?
The main challenge of this research is that the data we access is often stored in lots of different places such as different NHS Trusts. Therefore, we work closely with our colleagues at our partner sites to ensure the data we need is extracted correctly and all linked together into one large data warehouse. To do this, we work with the Clinical Data Linkage Services (CDLS) who are experts in this field.
4. How will using data linkage give us a full picture of the different problem’s women could be facing in pregnancy during Covid-19?
The Covid-19 pandemic has not only altered our personal lives dramatically since March 2020 but also has altered the research landscape. All non-critical in-person research studies and laboratory research were put on hold until it was safe to continue again. However, as data linkage research does not require patient involvement, except for access to electronic clinical records, it was possible to continue our research whilst other projects were stopped.
We are able to obtain rich data about health services during this period which allows us to have an early glimpse into the impact that the pandemic is having on the clinical services and service users. Within my teams’ research, we are able to see the impact of the pandemic on maternity care service users for example, the impact of the Covid-19 pandemic on the health and care of women experiencing mental illness and domestic violence and abuse, during pregnancy.
The beauty of using electronic patient records for Covid-19 research, is that we are able to look at changes across time in a dynamic data set which captures the potential changes in service use during the pandemic. Within ARC South London, there is research currently underway to look at the effects of Covid-19 on the reporting and rates of domestic violence and metal health referrals, and the impact of inequalities and deprivation within the maternity service user population using eLIXIR.
5. What do you hope this research will achieve that wasn’t previously possible without access to data linkage technology?
Much of the research looking at the ‘life course approach’ to disease prevention from pregnancy and infancy onwards has been developed from large birth cohorts, such as the Avon longitudinal study of parents and children and Born in Bradford. However, these directly recruited cohorts are by definition drawn from individuals recruited over a prespecified and limited time period and therefore become rapidly outdated when there are changes in population demography, lifestyle, and ethnicity.
Additionally, these cohorts are expensive to establish and sustain, with high dropout rates which can introduce biases within the cohort itself, such as lower levels of engagement in participants with mental health conditions for example. Direct patient recruitment into research cohorts may result in cohorts with a limited representation of the target population because some societal groups are less likely to take part in research projects, which is known as selective inclusion.
Therefore, using linked data from health records provides an effective, inclusive, and sustainable alternative to traditional research cohorts and has the ability to be linked to a variety of other datasets creating unique databases for researchers to use in future.
