Research projects using your official records

Children of the 90s research uses your official records to help with our research. There is general information about how we do this in 'How we use your official records' above. Over the past few years we have written to all of you to ask if you are happy for us to use your records in this way. We fully accept your right to decide that you don’t want us to access your records, and if you feel this way it is important that you tell us.

Many of you have sent back a decision form letting us know how you want your records used. We will always respect the decision you tell us.

In some circumstances, where research is in the public interest, researchers may be allowed to extract information from your records and use them in research without your consent. This includes information from your health and education records and any criminal convictions or cautions you may have. This only happens when we have asked for your consent and you haven’t responded. It does not let us access the records of people who have told us they don’t want this to happen. For this reason it is important that you return your consent form, particularly if you don’t want us to link to your records.

The research projects listed on this page all need information from official records. Please let us know if you have any questions or if you object to your records being used:

Email: alspac-linkage@bristol.ac.uk
Phone: 0117 33 10010
By post: Data Linkage Team, Children of the 90s, Oakfield House, Oakfield Grove, Bristol BS8 2BN

If you let us know before the project starts then we can exclude your records from the research. Once the research has started it will not be possible to exclude your records.

How we are using your records

Upcoming projects

  

Predictors of blood mercury levels during pregnancy

Mercury is a toxic metal released into the environment through natural and industrial processes. There is evidence that humans can be exposed to trace quantities of mercury through diet – such as fish, meat, and vegetables, air and water pollution, tea consumption, and use of traditional medicines. Other factors appear to be predictors of mercury levels, such as our age, ethnicity, socioeconomic status, and occupation. Over time, harmful quantities can accumulate within our bodies and this has been linked to poorer cardiovascular, renal, and reproductive health.

Although dietary consumption of fish is assumed to be a primary source of mercury in humans, there has been little research into the relative importance of all these different factors. By quantifying how much each of the above sources or predictors affects the levels of mercury we are exposed to, we can make stronger conclusions about what the key risk factors are for mercury exposure.

This study aims to evaluate the link between potential predictors of mercury levels, and mercury found in blood samples taken during pregnancy in ALSPAC. This will include comparing to anonymised residential area, to assess whether there is evidence of geographic variation perhaps caused by local air quality. 

Who will carry out the research? Researchers at the University of Bristol
Whose records are being used? Children of the 90s mothers
Which records are being used?

Those who provided maternal blood samples for metal analysis.

The project start date: 1 September 2022

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title). 

More information on record linkage and how to update how your records are used

Investigating sleep and mental health in autistic children and adolescents 

Disordered sleep is commonly reported in autism from a young age, as are symptoms of mental illness. Mental health and sleep are closely related within the general population but the nature of the association between sleep and mental health problems in autism is poorly understood. More generally, the underlying causes of sleep problems in autism are unknown. As a result, current treatments for sleep problems are largely ineffective in autistic people, and they also face severe consequences of mental ill health, such as high rates of suicidality and in-patient care. We aim to characterise the relationship between sleep problems and mental ill health (and identify factors underpinning these sleep problems) in young people with autism and in people with autistic traits. We will focus specifically on childhood and adolescence as this comprises the typical age-range of onset for problems in both sleep and mental health. Our approach to answering these questions will involve statistical modelling of longitudinal data on sleep and mental health in the ALSPAC cohort. Ultimately we hope that new knowledge from this work will inform future interventions for sleep and mental health in autistic children and adolescents.

Who will carry out the research? Researchers at the University of Edinburgh
Whose records are being used? Data used from Children of the 90s
Which records are being used?

Primary care and special education data

The project start date: April 2022

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title). 

For more information please see our FAQs page or email info@childrenofthe90s.ac.uk

More information on record linkage and how to update how your records are used

Association between air pollution and cardiovascular health in young adults (LongITools) 

A growing body of evidence has shown that exposure to air pollution is associated with higher blood pressure/hypertension, cardiovascular events, and cardiovascular mortality. However, few studies have assessed the impact of air pollution on cardiovascular health in younger individuals.

A meta-analysis of cross-sectional and longitudinal studies has shown that an increase in PM2.5 was associated with higher carotid intima-media thickness (CIMT). Even though there is a growing body of evidence on the association between air pollution and cardiovascular outcomes later in life, very little is known in younger individuals [3]. A study carried out with young adults (mean age 28, SD 1.0) showed that nitrogen dioxide (NO2), but not PM2.5, was associated with increased pulse wave velocity (PWV).

It is also possible that the associations between air pollution and cardiovascular health outcomes differ according to intermediate factors, such as body mass index (BMI). A study with 158 individuals aged 17-22 years found that a 1 standard deviation (SD) change in long-term NO2 exposure was associated with 11.3mg/dL higher total cholesterol and 9.4mg/dL higher low-density lipoprotein cholesterol (LDL-C), and these associations were stronger amongst obese participants, suggesting that obesity might exacerbate the effects of air pollution.

The aim of this study is to assess the long-term associations of air pollution with several measures of cardiovascular health in young adults (i.e. central and peripheral blood pressure, heart rate, PWV and CIMT) and explore possible effect modifications by BMI in these associations.

Who will carry out the research? Researchers at the University of Bristol 
Whose records are being used? Data used from Children of the 90s
Which records are being used?

Air pollution geodata

The project start date: February 2022

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title). 

For more information please see our FAQs page or email info@childrenofthe90s.ac.uk

More information on record linkage and how to update how your records are used

 

Early-life ambient environmental exposures and blood pressure trajectories (LongITools)  

Blood pressure tracks from childhood to adulthood, and elevated blood pressure in childhood or adolescence is associated with several intermediate markers of cardiovascular disease (CVD) and with CVD events and mortality in adulthood. There is a growing body of evidence showing that ambient environmental exposures, such as air pollution, noise and many characteristics of the built environment are associated with high blood pressure/hypertension in adulthood, and some associations with blood pressure have also been observed in children.

Early-life, especially prenatal and early postnatal, is a period of rapid development and particularly vulnerable to environmental factors, and adverse exposures in this period could lead to long-term health effects, including higher risk of CVD. Some studies have shown associations between prenatal ambient environmental factors and blood pressure in children, including some measures of the built environment (e.g., facility density, facility richness and building density), noise, temperature, and air pollution. Investigating whether early-life ambient environmental factors are also associated with changes in blood pressure in different developmental periods will further contribute to the understanding of the importance of environmental exposures to the risk of hypertension across the life-course.

Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC), we aim to assess the association of a range of ambient environmental exposures in early-life with changes in systolic (SBP) and diastolic blood pressure (DBP) during three developmental periods: childhood, adolescence, and early adulthood. We will also seek to replicate the associations found in ALSPAC in other independent European cohorts part of the LongITools project (Generation R, EDEN, PANIC and NFBC 1986).

Who will carry out the research? Researchers at the University of Bristol
Whose records are being used? Data used from Children of the 90s
Which records are being used? Air pollution geodata
The project start date: February 2022

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title). 

For more information please see our FAQs page or email info@childrenofthe90s.ac.uk

More information on record linkage and how to update how your records are used

 

 

Longitudinal associations of air pollution, noise and built environment with glucose and insulin-related traits (LongITools) 

Key modifiable risk factors for hyperglycaemia/diabetes include unhealthy diet, lack of physical activity and overweight/obesity. These are, in part, determined by the built environment, which comprises components such as walkability index, accessibility, population density, land use mix, and food environment. Most of the research assessing the association between built environment and glycaemic traits assesses type 2 diabetes mellitus (T2DM) in adulthood as an endpoint. Very few studies have assessed the association between the built environment and glucose and insulin-related traits in children/adolescents.

The association between air pollution and glucose and insulin-related traits has been more widely studied. Exposures to PM10 and PM2.5 have been associated with higher fasting blood glucose, and several meta-analyses have shown that air pollution is associated with the prevalence and incidence of T2DM. Air pollution, more specifically NO2 and PM10, has also been associated with insulin levels and insulin resistance, and some of these associations have been observed in childhood.

There is also evidence for associations between noise and higher prevalence and incidence of T2DM. To the best of our knowledge, no studies have assessed noise and glucose and insulin-related traits in childhood/adolescence.

This study aims to assess the associations of built environment, air pollution and noise with longitudinal changes in glucose, glycated haemoglobin, insulin and insulin resistance from childhood to early adulthood using data from European prospective studies.

Who will carry out the research? Researchers at the University of Bristol
Whose records are being used? Data used from Children of the 90s
Which records are being used? Air pollution geodata
The project start date: February 2022

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title). 

More information on record linkage and how to update how your records are used

 

Prenatal air pollution, fetal growth, inflammation, and childhood adiposity (LongITools and LifeCycle) 

There is inconsistent evidence of an association between prenatal exposure to air pollution and adiposity in childhood. Some studies suggest positive associations, possibly with stronger magnitude in boys, some find no association, and others find inverse associations between prenatal air pollution and adiposity in childhood. Most studies have been relatively small (<3,500 participants) and assess adiposity at a single time point.

The potential mechanisms linking air pollution to adiposity are still uncertain. Maternal exposure to air pollution may affect fetal growth, and intrauterine growth restriction will influence later-life adiposity. Inflammation is another hypothesised mechanism of the association between prenatal air pollution and offspring adiposity, and this might also be part of the fetal growth pathway.

Using data from three birth cohorts (ALSPAC, BiB and Generation R), this project will assess the association of different measures of air pollution (PM10, PM2.5, NO2 and NO) during pregnancy with fetal growth, trajectories of adiposity in childhood, and maternal and offspring inflammation. We will also explore possible sensitive windows by assessing trimester-specific associations, and whether associations differ by sex. If associations of air pollution with fetal growth, inflammation and childhood adiposity are evident, we will explore and quantify possible mediation by fetal growth and inflammation in the association between prenatal air pollution and childhood adiposity.

Who will carry out the research? Researchers at the University of Bristol
Whose records are being used? Data used from Children of the 90s
Which records are being used? Air pollution geodata
The project start date: February 2022

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title). 

More information on record linkage and how to update how your records are used

 

Mapping disparities in childhood lead exposure in England 

Our project aims to estimate the prevalence and distribution, in terms of geography and socioeconomic status, of lead exposure in England and its costs in terms of children’s wellbeing and development. While scholars and practitioners believe lead exposure to be widespread in England, a dearth of data on this issue has so far hindered policymaking. We will perform a secondary data analysis, building on international evidence to project exposure burden in England. ALSPAC data provide unique measurements of lead levels for a small area in the 1990s that will inform our estimates nationwide.

Who will carry out the research? Researchers at the University of Oxford 
Whose records are being used? Data used from Children of the 90s 
Which records are being used?

Address and geodata

The project start date: January 2022

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title). 

More information on record linkage and how to update how your records are used

 

 

 

Who will carry out the research? Researchers at 
Whose records are being used? The Children of the 90s young adults
Which records are being used?

 

The project start date:  

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title).

More information on record linkage and how to update how your records are used 

 

Ongoing projects

Neuro-developmental outcome after anaesthesia in early childhood 

All the commonly used drugs that produce general anaesthesia have been shown to increase brain cell death in young laboratory animals and lead to abnormal function later on. Mounting concern about the potentially toxic effects of anaesthetic drugs on the young brain has led to 76 studies since 1990 which have attempted to measure the brain development and functioning of humans who were given general anaesthetics for surgery or procedures in early childhood. Aspects of brain development which have been examined include measures of intelligence, movement and co-ordination, behaviour, language and speech, literacy and numeracy. Other measures have included academic achievement in school and diagnoses of learning disability, autism and attention deficit hyperactivity disorder (ADHD).

Unfortunately, these human studies are frequently limited quality, with: too few children (on average 130 cases), no method to account for other causes of adverse brain development which could bias the results, no information on the duration and type of general anaesthetic drugs given and not specifically designed to assess children's brain development. Their results are conflicting and somewhat difficult to interpret. At present, it remains uncertain whether anaesthetic drugs are harming young children’s brains. The definitive results of a single clinical trial specifically designed to address this important question are not due for several years. In the meantime, the number of published review articles, commentaries, consensus statements and statements by regulatory bodies continues to grow. The United States Food and Drug Association urges careful consideration of the risks and benefits of a general anaesthetic in young children and pregnant women undergoing anaesthesia which may last longer than three hours or require multiple procedures.

Our project will determine whether there is evidence of impaired long-term brain development in ALSPAC data, specifically those children who had general anaesthetics for surgery or procedures before the age of four. We anticipate that the detailed information recorded about these children and their parents, as well as the quality of assessment of their brain development throughout childhood and adolescence, will allow us to better investigate this important issue than previous human studies have been able to do. We also propose to collect new information from childrens' medical records in order to describe the types and duration of general anaesthetics which were given in the early 1990s for different surgeries or unpleasant procedures. This will help us to determine whether increased duration of anaesthesia is associated with additionally worse brain development, and will allow us to place the findings of the ALSPAC study in context with changes to paediatric anaesthetic practice in the last two decades, as well as enhancing the utility of the ALSPAC resource to future anaesthetic research.

Who will carry out the research? Researchers at the University of Bristol
Whose records are being used? The Children of the 90s young adults
Which records are being used?  Health records from hospital visits
The project start date:  28 October 2019

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title). 

More information on record linkage and how to update how your records are used 

 

Understanding the causes and consequences of having an intellectual disability 

People with intellectual disability (also called learning disabilities) have difficulties in understanding new or complex information, in learning new skills and a reduced ability to cope independently, which started before adulthood. People with intellectual disability often have poor long-term outcomes and inequalities compared to the general population. This includes reduced access to and effectiveness of health care, difficulties in education and employment, and higher chances of early death.

Many causes of intellectual disability are genetic in nature. Others are influenced by the environment before (pregnancy) or around the time of their birth (the perinatal period), and in childhood. The Children of the 90s study provides the opportunity to explore how our genes and early life environment can influence the risk of developing an intellectual disability. This project will use information you have given to Children of the 90s in questionnaires and at focus clinics as well as data from GP records and hospital visits to investigate the causes and consequences of having an intellectual disability.

Our first project will look at whether there is a link between mother’s substance use (such as alcohol and tobacco) in pregnancy and the child’s risk of intellectual disability. These substances are known to influence the development of the fetus in the womb, but whether they cause problems like intellectual disability is not known. Understanding such a link is important, as it may help guide policy and help pregnant women make informed choices about the risks of substance use in pregnancy. In the future, we will be interested in understanding the role of other factors in the development of intellectual disability, and also aim to understand the longer term outcomes of having intellectual disability.

Who will carry out the research? Researchers at the University of Bristol
Whose records are being used? The Children of the 90s young adults
Which records are being used?

1. Department for Education and local authority records on children who had a statement of special educational needs

2. Health records (from your GP, hospital visits and community mental healthcare providers) about diagnoses of intellectual disability

The project start date: 27 May 2019

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title). 

More information on record linkage and how to update how your records are used 

Using linked electronic health data to improve eczema diagnosis and outcomes 

Eczema (also known as atopic dermatitis) affects 20% of children and up to 10% of adults, and is becoming more common globally. Eczema is a challenging disease characterised by itch, sleeplessness, discomfort, stress and stigma for sufferers, but it looks very different and the disease takes different courses in different people, and no single treatment for it works for everyone. This suggests that there may be different diseases, all of which get called eczema, but which may in fact be clinically distinguishable subtypes with different prognoses and treatment needs.

We want to find out whether this is true, and to do this we will look for groups of children where the course of disease and other clinical characteristics such as immunological profile, demographics and other comorbid diseases are very similar within group, but different across groups. This will help us characterise these subtypes and in future lead to better estimates of whether the disease will resolve on its own or require medical intervention, and eventually better and more personalised treatment recommendations.

This study is currently investigating eczema subtypes with an approach called latent class analysis using data from children in the original ALSPAC cohort. We would like to expand on this by looking at linked primary care electronic health records, in order to 1) see if we can replicate our findings using data collected in real-world settings, 2) add to the characterisation of subtypes with additional information not contained in the cohort collections, and 3) do an exploratory analysis to see if phenotypes can be derived based solely on data from electronic health records.

Who will carry out the research? Researchers at the London School of Hygiene and Tropical Medicine
Whose records are being used? The Children of the 90s young adults
Which records are being used?

1. Data from mother and child questionnaires (all years) with information about eczema

2. Linked primary care records relating to eczema

The project start date: 15 April 2019

Remember: you need to let us know by the given date if you don’t want your records used in this way. If you’d like to opt-out of a specific project please email alspac-linkage@bristol.ac.uk (quoting the project title). 

More information on record linkage and how to update how your records are used 

 

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