Tracking the Impact of Gestational Age on health, educational and economic outcomes: a longitudinal Record linkage study.
What are we trying to do?
TIGAR is a large study of children born in England in 2005-6. The aim of TIGAR is to:
Compare the health and school achievement of children born prematurely with those born after a full term pregnancy.
Find out whether being born prematurely has a larger impact on children who are living in poverty or are socially disadvantaged.
Measure the costs of prematurity to health and education services – this will help plan future health and education services.
Why are we doing this?
A typical full term pregnancy lasts about 40 weeks and babies born before 37 weeks of pregnancy are classified as preterm or premature.
Most premature babies survive and do very well in the long term, but as a group they:
Are more likely to have difficulties with their health
Are more likely to have difficulties with their development
Are more likely to have special educational needs
May not perform as well as their classmates in school tests.
Even babies who are born just a few weeks early may have more challenges in childhood than those who are born after a full term pregnancy.
Studies of the long term effects of premature birth need to be based on a lot of children (at least 100,000) to find out what kinds of challenges premature children may have throughout their childhood. See box 1 below to find out why.
Studies as large as this have been done in the past, but their findings may not be relevant to children born in England today. See box 2 below to find out why.
We need a large study to assess the health, school achievement, and costs associated with premature birth in babies born in England in the 21st century.
How will we do this and who is responsible for the data we collect?
TIGAR will use information about all children born in England during 2005 and 2006. This will include about one million children. Information on the children will be obtained from different sources:
Records of any hospital care they have had up to 10 years of age
The information from the birth records, hospitals and schools will be linked together by independent organisations with experience in record linkage. They will keep the data secure and remove personally identifiable information (e.g. NHS number, date of birth) before allowing the TIGAR team to analyse it. See box 4 below for more details.
The information that the TIGAR team will use for analysis will:
Not include personally identifiable information (e.g. NHS number, date of birth, name), so we will not be able to identify any individual children or families.
Give us a picture of each child's health and school results, and will enable us to see how much this is affected by being born prematurely.
Under the General Data Protection Regulation (GDPR), the 'data controller' is responsible for what happens to data which is collected. The 'data controller' for the data which is analysed by the TIGAR team is the University of Oxford. If you would like to contact us directly for more information about how we process and protect data collected for TIGAR, please email Professor Maria Quigley (firstname.lastname@example.org).
No, unfortunately this is not possible. The TIGAR study aims to include all children born in England during 2005 and 2006. This is about million children. It is therefore not possible for us to ask all the parents if we can use the information about their child. For this reason we have applied for special permission to access the children's records without the permission of their parents. See box 5 below for more details.
Can I opt out of my child being included in the study?
It may be possible to opt out, some individuals in England have opted out of sharing their health data. For example, they have chosen to prevent confidential information being shared between organisations like their GP practice and hospitals. If you have already opted out of data sharing, at the time when the datasets are being linked or the linkage is being checked (see Box 4), then your data will not be included in our study. However, once the TIGAR team receive the data (with personal identifiable information removed) for the analysis of the children's health or education, the TIGAR team will not be able to identify any individual child or family from the information it will hold and therefore they will not be able to exclude them.
For more information about the sharing of the confidential health data of yourself or your children, please contact your GP. Alternatively, please look at the NHS Digital website.
Who is organising and funding this research?
TIGAR is being funded by the UK Medical Research Council.
TIGAR is being led by Maria Quigley (National Perinatal Epidemiology Unit, University of Oxford) together with Elaine Boyle, Claire Carson, Victoria Coathup, Nirupa Dattani, Samantha Johnson, Jenny Kurinczuk, Alison Macfarlane, Stavros Petrou and Oliver Rivero Arias.
Three groups have been formed to advise on the project:
An Advisory Group includes experts, voluntary organisations, such as the support group 'BLISS for babies born too soon, too small, too sick', and representatives of families affected by premature birth.
A Patient, Parent and Public Involvement Group will provide patients' and parents' perspectives on all aspects of the project. Members will include families affected by premature birth (e.g. parents of premature children, and young adults who were born prematurely).
Another group includes parents who are both affected by premature birth and who are also professionals with an interest in this area.
What will happen to the results of TIGAR?
The results of TIGAR will be published in scientific journals.
We will put a summary of the results on the TIGAR website.
The results will also be made available to professionals and organisations who provide health and education services for children. For example the results will provide information on:
whether more premature babies should be routinely followed up after the early weeks of life
the type of difficulties premature children may have as they are growing up
what kind of support premature children may need in school
The results will help counsel parents about the types of challenges that premature children may have later in life – this will help parents be more prepared about what to expect in the future and when to seek help from professionals.
Our results on the costs associated with prematurity will be helpful to organisations who plan or deliver health and education services – this will help ensure that premature children who need help are identified and given support.
How long will personal data be stored?
The results of TIGAR will be published in scientific journals. After a paper is published, we may be contacted by other researchers who want us to do a bit more investigation into one of our results. Therefore, we will store the personal data for two years after the final paper is published to allow us to do this.
If you wish to raise a complaint on how we have handled your personal data, you can contact our Data Protection Officer (email@example.com), who will investigate the matter. If you are not satisfied with our response or believe we are processing your personal data in a way that is not lawful, you can complain to the Information Commissioner's Office (ICO).
Who can I contact for more information?
For more information, please see the TIGAR website (www.npeu.ox.ac.uk/tigar) or contact Professor Maria Quigley (email firstname.lastname@example.org or phone 01865 289700).
About 7% of babies (or 1 in every 14) are born prematurely each year in England. About 0.5% of babies (or 1 in every 200) are born at less than 28 weeks of pregnancy.
If we selected 200 babies born in England this year, we would expect one to be born at less than 28 weeks of pregnancy – we would not be able to build an accurate picture of the long term impact from this one child.
If we selected 100,000 babies born in England this year, we would expect 500 to be born at less than 28 weeks – these 500 could help us build a more accurate picture.
We need to study many children to ensure that we have included enough children who were born at each of the different weeks of pregnancy e.g. 24 weeks, 25 weeks, 26 weeks, and so on.
Therefore, studies of the long term impact of premature birth need to be based on very large numbers of children to find out what kinds of challenges premature children may have throughout their childhood.
There have been some very large studies of premature children in the past, but they are mostly based on:
Children born from the 1960s to the 1990s who experienced different care in the early days and weeks of life compared with babies born today.
Children living in other countries, who will have experienced different health and education systems compared with children born in England.
TIGAR will include all babies born in England in 2005 and 2006
When births are registered, the Officefor National Statistics (ONS) information on the baby's sex, gestation, birth weight and some family characteristics.
When children have hospital care, information is collected on their age, diagnosis, how long they were in hospital, etc.
The Department for Education (DfE) records information on children's school results (e.g. SATs), special education needs (e.g. type and support given) and some family characteristics.
The information from the birth records, hospitals and schools will be linked together by two independent organisations with experience in record linkage:
Education Data Division of the Department for Education.
Their work is governed by the General Data Protection Regulation (GDPR) and confidentiality agreements to ensure that the data are kept securely. Members of the TIGAR team will apply to access some personally identifiable information (the child's NHS number, date of birth and postcode) so that they can check the linkage. The 'ONS approved' TIGAR researchers will do this using the secure Virtual Microdata Laboratory facilities at ONS. Access to the data using these facilities will only happen at certain stages of the project: first to check the linkage to the hospital data, and then to check the linkage to the school data. Once checked, ONS will produce a dataset (with personal identifiers removed) which will be used by the TIGAR team to analyse the data and produce results. Any information that might identify individual children or families (e.g. names, postcodes, dates of birth, NHS numbers) will be removed before being analysed by the TIGAR team.
We have applied for special permission to access the children's records.
The legal basis for the special permission to process and store personal data for TIGAR is that it is 'a task in the public interest' (article 6(e)) and that sensitive personal data is necessary for archiving purposes in the public interest, scientific or historical research purposes or statistical purposes (article 9 (2) (j), based on Article 89 (1)). This is particularly pertinent to the use of personal identifiers for the linkage by NHS-Digital. The dataset released to the research team for the analysis of the children's health or education is 'pseudonymised', meaning that we have no access to personal/sensitive personal data such as name, date of birth or NHS number.
The special permissions are given through the:
Confidentiality Advisory Group at the Health Research Authority (CAG reference: 15/CAG/0196)
Education Data Division of the Department for Education.
We have also obtained approval for the research from the Southwest – Frenchay Research Ethics Committee (REC reference 15/SW/0294).
Some of the findings of this study have now been published. They show that gestational age at birth is a strong predictor of ill health throughout childhood.
The TIGAR study analysed hospital admission data for more than a million children born in England in 2005-2006. Some of the findings, which were published in the BMJ found that children born early (less than 37 weeks gestation) had more hospital admissions than those born at full term (around 40 weeks) – in general, the more preterm you were, the more hospital admissions you had. Even children born a few weeks early had more hospital admissions than those born at full term. The effect of gestational age on hospital admissions became smaller as the children got older but it did not disappear - there was still an effect even at age 7-10 years.
Infection was the most common cause of hospital admission at all ages so strategies aimed at the prevention and management of childhood infections is important, particularly in children born preterm. Many preterm births cannot be avoided. For example, if there are concerns about the wellbeing of the mother or baby during pregnancy, it may not be appropriate to delay the birth. But if this decision is not clear cut, then it is important to weigh up the risks associated with delaying the birth with the risks associated with being born early.
Other papers from the TIGAR study can be found by visiting the following links: