Search/filter projects:
- Professor Carol Joinson - Dr Christina Dardani -
Observational studies have found evidence that depression and anxiety are prospectively associated with lower urinary tract symptoms (LUTS) in women. Although prospective studies provide evidence of the direction of observed associations, they are limited by unmeasured and residual confounding. Observational studies that rely on self-report questionnaires to assess depression and anxiety exposures are also limited by measurement error. Polygenic risk scores (PRS) can be used estimate an individual’s underlying genetic liability to complex traits such as depression and anxiety. PRS should not be associated with genetic or environmental confounders at a population level, which can bias observational studies.
This project, based on data from the ALSPAC mothers’ cohort, will examine the relationship between depression, anxiety and LUTS using PRS for depression and anxiety derived from genetic variants identified in published genome wide association studies. The analysis will examine evidence for differential associations between the depression/anxiety PRS and LUTS including different subtypes of urinary incontinence (UI) (stress UI, urgency UI, mixed UI), urinary urgency, and nocturia.
Logistic regression analysis will be used to examine the associations between the PRS for depression/anxiety and binary variables for the LUTS phenotypes. Analyses will be adjusted for the first ten principal components of the ALSPAC genotype data.
Als TD et al. Nat Med. 2023 Jul;29(7):1832-1844.
Purves, K.L., et al. Molecular Psychiatry, 2020. 25(12): p. 3292-3303.
Felde G, Ebbesen MH, Hunskaar S. Neurourol Urodyn 2017 Feb;36(2):322-328.
- Dr Ben Faber - Dr Rhona Beynon -
Osteoarthritis (OA) is a leading cause of disability, particularly among older people (1). It can affect any joint in the body, but two of the most commonly afflicted sites are the knees and hip (2). There is currently no cure for the disease, leaving patients to trial a combination of supportive therapies to attempt to alleviate symptoms. If unsuccessful, joint replacement is the last resort.
Previous studies indicate that hip OA affects men and women at similar rates, while knee OA is more prevalent among women (3). Alongside age and gender, obesity has been found to significantly contribute to the onset and progression of OA at the knee, and to a lesser extent, at the hip (4-6).
Genetic studies have suggested knee and hip OA have shared and independent genetic causes (7). However, the interrelation between OA in these joints is unclear, raising the question of whether OA in one joint increases susceptibility in the other or if they exist as distinct and separate conditions.
This project uses data already derived from the left knee and hip of approximately 40,000 individuals in UK Biobank. It aims to:
(i) Assess the prevalence of radiographic OA (rOA) at the hip and knee joint, unilaterally and bilaterally.
(ii) Compare associations of known OA risk factors (e.g., age, sex, weight) with the risk of rOA at the hip and knee.
(iii) Explore potential associations between rOA at the knee and hip.
This epidemiological study involves cross-sectional analyses. The student will gain skills in using descriptive statistics (means, frequencies, standard deviations) to explore the dataset, create plots for visualising the relationships between rOA and established risk factors, and employ contingency tables and chi-squared tests to assess the relationship between rOA at the hip and knee.
Subsequently, students will receive guidance on conducting regression analyses, including logistic regression models, to quantify associations between established OA risk factors and rOA. This analysis will assess whether these associations differ between joints. Furthermore, regression techniques will be used to explore whether the presence of rOA in one joint increases the likelihood of having rOA in the other joint. All analyses will be executed using the STATA software package.
The student will have the opportunity to draft an abstract for submission to both national and international conferences and potentially expand their dissertation into a research paper suitable for journal submission.
1. Cross M, Smith E, Hoy D, Nolte S, Ackerman I, Fransen M, et al. The global burden of hip and knee osteoarthritis: estimates from the global burden of disease 2010 study. Ann Rheum Dis. 2014;73(7):1323-30.
2. NHS. Osteoarthritis 2023 [17.08.23]. Available from: https://www.nhs.uk/conditions/osteoarthritis/.
3. Srikanth VK, Fryer JL, Zhai G, Winzenberg TM, Hosmer D, Jones G. A meta-analysis of sex differences prevalence, incidence and severity of osteoarthritis. Osteoarthritis Cartilage. 2005;13(9):769-81.
4. King LK, March L, Anandacoomarasamy A. Obesity & osteoarthritis. Indian J Med Res. 2013;138(2):185-93.
5. Lohmander LS, Gerhardsson de Verdier M, Rollof J, Nilsson PM, Engstrom G. Incidence of severe knee and hip osteoarthritis in relation to different measures of body mass: a population-based prospective cohort study. Ann Rheum Dis. 2009;68(4):490-6.
6. Funck-Brentano T, Nethander M, Moverare-Skrtic S, Richette P, Ohlsson C. Causal Factors for Knee, Hip, and Hand Osteoarthritis: A Mendelian Randomization Study in the UK Biobank. Arthritis Rheumatol. 2019;71(10):1634-41.
7. Boer CG, Hatzikotoulas K, Southam L, Stefansdottir L, Zhang Y, Coutinho de Almeida R, et al. Deciphering osteoarthritis genetics across 826,690 individuals from 9 populations. Cell. 2021;184(18):4784-818 e17.
- Nancy McBride (lead) - Dr Carolina Borges -
Our knowledge of the mechanisms that underpin gestational age (GA), and related pregnancy disorders, such as pre term birth (PTB – births < 37 weeks gestation), and very preterm birth (vPTB, births < 34 weeks gestation), is still poor (1).
PTB affects around 15 million births worldwide each year, and is the largest contributor to fetal mortality and morbidity (2). While we know there are clinical factors and other co-morbid disorders of pregnancy that increase risk of PTB, we still do not know what a woman’s gestational duration will be when she first attends clinic, and often until she signs symptoms of spontaneous pre term labour.
Metabolomics may help us elucidate more about these mechanisms. The NMR platform quantifies metabolic traits. The targeted metabolic traits measured by the platform represent a broad molecular signature of metabolism including routine lipids, lipoprotein subclass profiling, fatty acid composition and several low-molecular metabolites, including amino acids, ketone bodies and gluconeogenesis-related metabolites (3).
Metabolomics can improve our understanding of pregnancy-related disorders because metabolite levels are known to change markedly during pregnancy and may reflect underlying pathophysiology (4-6). Changes in metabolite profiles have been previously associated with other pregnancy-related disorders as well as adverse cardio-metabolic outcomes that associate with pregnancy related disorders (4, 7).
We have access to pregnancy and birth cohorts of mothers and offspring within which this can be explored, within the MR-PREG consortium. In a previous study of 7,440 pregnant participants of the Born in Bradford cohort, maternal dyslipidaemia in the second trimester was associated with a shorter GA at birth (8). These associations may be explained by residual confounding and reverse causality. Mendelian randomization (MR) is a causal inference technique which can help to elucidate whether these associations are causal (9). We hope to identify the metabolic changes underlying the physiological onset of labour to help develop new clinically useful strategies and identify potential drug targets (1).
The aim of this study is to explore the causal effect of maternal metabolites on the risk of PTB, it’s subtypes, and gestational age, using MR.
This study will be undertaken within the MR-PREG collaboration, which aims to explore causes and consequences of different pregnancy and perinatal outcomes. The PhD candidate will have access to the largest genome-wide association studies (GWAS) currently available for NMR-profiled metabolites (using data from ~300,000 UK Biobank individuals) and large meta-analyses conducted in European cohorts of GA/PTB (births <37 weeks, and subtypes such as very-pre-term birth, <34 weeks). We will use these to identify genetic instruments for metabolites and PTB / gestational age, and use two-sample Mendelian randomisation to probe the causal role of metabolites on gestational age and PTB.
1. Following Spontaneous Labour at Term in Humans Using Untargeted Metabolomics Analysis: A Pilot Study. LID - 10.3390/ijerph16091527 [doi] LID - 1527. (1660-4601 (Electronic)).
2. Stock SJ, Horne M, Bruijn M, White H, Boyd KA, Heggie R, et al. Development and validation of a risk prediction model of preterm birth for women with preterm labour symptoms (the QUIDS study): A prospective cohort study and individual participant data meta-analysis. PLOS Medicine. 2021;18(7):e1003686.
3. Dunn WB, Bailey NJC, Johnson HE. Measuring the metabolome: current analytical technologies. Analyst. 2005;130(5):606-25.
4. McBride N, White SL, Farrar D, Poston L, Sattar N, Nelson SM, et al. Do nuclear magnetic resonance (NMR)-based metabolomics improve the prediction of pregnancy-related disorders? medRxiv. 2020:2020.06.22.20134650.
5. Souza RT, Galvão RB, Leite DA-O, Passini R, Jr., Baker P, Cecatti JA-O. Use of metabolomics for predicting spontaneous preterm birth in asymptomatic pregnant women: protocol for a systematic review and meta-analysis. (2044-6055 (Electronic)).
6. Considine EC, Khashan AS, Kenny LC. Screening for Preterm Birth: Potential for a Metabolomics Biomarker Panel. Metabolites. 2019;9(5):90.
7. White SL, Pasupathy D, Sattar N, Nelson SM, Lawlor DA, Briley AL, et al. Metabolic profiling of gestational diabetes in obese women during pregnancy. (1432-0428 (Electronic)).
8. Birchenall KA. Investigating the trigger for human parturition using metabolomic and phosphoproteomic techniques within case-control and cohort studies: University of Bristol; 2020.
9. Skrivankova VW, Richmond RC, Woolf BAR, Davies NM, Swanson SA, VanderWeele TJ, et al. Strengthening the reporting of observational studies in epidemiology using mendelian randomisation (STROBE-MR): explanation and elaboration. BMJ. 2021;375:n2233.
- Dr Anna Hurley-Wallace (lead) - Dr Katie Whale -
Chronic musculoskeletal pain is a common issue experienced by adolescents and young adults (AYAs) [1,2,3], which can have a significant impact on their wellbeing [4,5]. Conditions include rheumatoid arthritis, hypermobility disorders, and Ehlers-Danlos Syndromes. A key challenge for AYAs is accessing, and subsequently engaging with appropriate multidisciplinary healthcare services for chronic musculoskeletal pain [6]. Musculoskeletal pain management programmes usually focus on physical or occupational therapy [7,8], with adjuvant psychological therapy and medications as appropriate. Barriers preventing AYAs from accessing and engaging with musculoskeletal pain management programmes remain unclear. By understanding these barriers, interventions and service improvements can be implemented to improve programme engagement.
Primary aim: Explore and summarise young people’s (16 to 24-years) experiences of accessing and engaging with musculoskeletal chronic pain programmes offered in secondary care. Objectives: (i) identify barriers to accessing musculoskeletal pain programmes, (ii) identify barriers and facilitators to successful engagement with musculoskeletal pain programmes, (iii) explore contextual factors that may be contributing to AYA levels of engagement with musculoskeletal pain programmes, (iv) draft a set of key recommendations for a co-intervention to improve AYA’s engagement with musculoskeletal pain programmes, focusing on engagement with the physical therapy component.
A secondary analysis of qualitative interview data, which was originally collected to capture young people’s experiences of online resources for chronic pain management[9]. The aim for this analysis is to explore and summarise experiences of accessing and engaging with pain management programmes within the musculoskeletal pain participant sub-set (n = 8), with potential expansion to the post-injury pain sub-set (n = 3). Thematic analysis will be conducted using NVivo [10]. Results should present the themes and suggest key recommendations for a co-intervention to improve AYA’s engagement with musculoskeletal pain programmes. Original transcripts and field notes are available.
1. King, S., Chambers, C. T., Huguet, A., MacNevin, R. C., McGrath, P. J., Parker, L., & MacDonald, A. J. (2011). The epidemiology of chronic pain in children and adolescents revisited: a systematic review. Pain, 152(12), 2729-2738. https://doi.org/10.1016/j.pain.2011.07.016
2. Kastelein, M., Luijsterburg, P. A. J., Heintjes, E. M., van Middelkoop, M., Verhaar, J. A. N., Koes, B. W., & Bierma-Zeinstra, S. M. A. (2015). The 6-year trajectory of non-traumatic knee symptoms (including patellofemoral pain) in adolescents and young adults in general practice: a study of clinical predictors. British Journal of Sports Medicine, 49(6), 400-405. http://dx.doi.org/10.1136/bjsports-2014-093557
3. Hanvold, T. N., Veiersted, K. B., & Wærsted, M. (2010). A prospective study of neck, shoulder, and upper back pain among technical school students entering working life. Journal of Adolescent Health, 46(5), 488-494. https://doi.org/10.1016/j.jadohealth.2009.11.200
4. Myrtveit, S. M., Sivertsen, B., Skogen, J. C., Frostholm, L., Stormark, K. M., & Hysing, M. (2014). Adolescent neck and shoulder pain—the association with depression, physical activity, screen-based activities, and use of health care services. Journal of Adolescent Health, 55(3), 366-372. https://doi.org/10.1016/j.jadohealth.2014.02.016
5. Rathleff, M. S., Holden, S., Straszek, C. L., Olesen, J. L., Jensen, M. B., & Roos, E. M. (2019). Five-year prognosis and impact of adolescent knee pain: a prospective population-based cohort study of 504 adolescents in Denmark. BMJ open, 9(5), e024113. http://dx.doi.org/10.1136/bmjopen-2018-024113
6. Slater, H., Jordan, J. E., Chua, J., Schütze, R., Wark, J. D., & Briggs, A. M. (2016). Young people's experiences of persistent musculoskeletal pain, needs, gaps and perceptions about the role of digital technologies to support their co-care: a qualitative study. BMJ open, 6(12), e014007. https://doi.org/10.1136/bmjopen-2016-014007
7. Caes, L., Fisher, E., Clinch, J., & Eccleston, C. (2018). Current evidence-based interdisciplinary treatment options for pediatric musculoskeletal pain. Current Treatment Options in Rheumatology, 4, 223-234. https://doi.org/10.1007/s40674-018-0101-7
8. Van Meulenbroek, T., Conijn, A. E. A., Huijnen, I. P. J., Engelbert, R. H. H., & Verbunt, J. A. (2020). Multidisciplinary Treatment for Hypermobile Adolescents with Chronic Musculoskeletal Pain. Journal of rehabilitation medicine. Clinical communications, 3, 1000033. https://doi.org/10.2340/20030711-1000033
9. Hurley-Wallace, A., Kirby, S., & Bishop, F. (2022). Trusting in the online 'community': An interview study exploring internet use in young people with chronic pain. British journal of pain, 16(3), 341–353. https://doi.org/10.1177/20494637211061970
10. Clarke, V., Braun, V., & Hayfield, N. (2015). Thematic analysis. Qualitative psychology: A practical guide to research methods, 3, 222-248.
- Dr Neil Goulding - Prof Abigail Fraser -
The aetiology of the hypertensive disorders of pregnancy (HDP; preeclampsia and gestational hypertension) is likely complex, involving both maternal vascular and inflammatory components. We hypothesize that women who experience a HDP will have a more adverse inflammatory profile later in life.
To investigate the associations of HDP with 92 individual inflammatory proteins measured in women at mean (standard deviation; SD) age 47.5 (4.4) in a population based prospective pregnancy cohort study (ALSPAC).
1. Conduct a review of the literature to gain insight into the pathogenesis of HDP.
2. Identify potential confounders of the relationship of interest.
3. Conduct multivariable regression analyses to estimate the relationships between HDP and the 92 proteins measured using the Olink Target 96 Inflammation Panel (Olink, Uppsala, Sweden).
4. Write up a report and if the student wishes to, prepare a manuscript for publication.
LA Magee et al. N Engl J Med 2022;386:1817-1832.
Fraser et. al. Int J Epidemiol 2013;97-110.
- Dr Mark Gormley - Dr Rebecca Richmond -
Ankyloglossia (‘tongue-tie’) is a common condition characterised by a short lingual frenulum. It has been associated with feeding difficulties, predominantly among breastfed infants, which can lead to inadequate nutrition and failure to thrive.
Tongue-tie is being more frequently diagnosed, particularly in high income countries. This may be due to increased breastfeeding or awareness of the condition. Another hypothesis is that rates are increasing due to folic acid (FA) supplementation during pregnancy, but the evidence remains insufficient.1
FA is protective against the development of neural tube defects and is recommended during the periconceptional period. It would not be advisable for expectant mothers to stop taking FA since the benefits outweigh the potential harms. Nonetheless, if tongue-tie was found to be influenced by maternal FA intake, this would raise further awareness of the condition and potential for early treatment through frenectomy, a simple and low risk procedure.
This project will investigate the relationship between maternal folate status and offspring tongue tie using data from mothers and children in the Avon Longitudinal Study of Parents and Children (ALSPAC).
Exposures will be maternal FA supplementation at 17 and 32 weeks of pregnancy, folate intake in the diet at 32 weeks of pregnancy and the methyltetrahydrofolate reductase (MTHFR) genotype.2
Outcomes will include reported tongue tie, infant feeding difficulties, breastfeeding cessation, and weight gain in infancy.
The analysis will involve multivariable linear and logistic regression analysis with adjustment for potential confounding factors (including maternal smoking, alcohol, body mass index, social class, education, dietary intake).
MTHFR genotype will be used to assess the causal role of maternal folate status in relation to tongue tie and related outcomes within a Mendelian randomization framework.2
Analyses will be further stratified by mode of infant feeding (breastfeeding exclusivity and duration).
1. Rubin, G., Stewart, C., McGowan, L., Woodside, J., Barrett, G., Godfrey, K., & Hall, J. (2023). Maternal folic acid supplementation and the risk of ankyloglossia (tongue-tie) in infants; a systematic review. Authorea, doi. 10.22541/au.168007870.09307215/v1.
2. Lewis, S. J., Leary, S., Smith, G. D., & Ness, A. (2009). Body composition at age 9 years, maternal folate intake during pregnancy and methyltetrahydrofolate reductase (MTHFR) C677T genotype. British Journal of Nutrition, 102(4), 493-496.
- Dr Tom Bond - Dr Apostolos Gkatzionis -
Studies of pregnancy outcomes are often conducted in samples that are restricted to women who are currently pregnant. This involves conditioning on pregnancy “incidence”, analogous to conditioning on disease incidence in studies of disease progression. In this situation pregnancy becomes a collider variable, which could induce spurious associations between causes of pregnancy that are truly independent in the source population. Furthermore, if any of the causes of pregnancy also cause the pregnancy outcome of interest then this could result in biased estimates of the true causal associations between risk factors and the pregnancy outcome. This is an example of index event bias (1), and the extent to which this could affect Mendelian randomization (MR) studies of pregnancy outcomes is currently unknown. This mini project will inform and influence a large number of MR investigations that we are currently conducting within the MR-PREG consortium.
1. Explore, via simulations and empirical analyses, the extent to which index event bias may affect MR studies of pregnancy outcomes.
2. Establish, via simulations and empirical analyses, whether existing methods can mitigate index event bias in MR studies of pregnancy outcomes.
We will conduct simulation studies and (where possible) real data analyses, to explore the extent to which two sample MR estimates of causal effects on pregnancy outcomes may be affected by index event bias under realistic assumptions. There will also be scope to conduct further simulation studies, along with applied example analyses, to test whether existing methods can mitigate index event bias in a two sample MR study of pregnancy outcomes. Relevant methods will include Slope-Hunter (2) and the method of Dudbridge et al. (3), which requires a GWAS of pregnancy incidence.
1. Mitchell RE, et al. PLOS Genetics. 2023;19(2):e1010596.
2. Mahmoud O, et al. Nature Communications. 2022;13(1):619.
3. Dudbridge F, et al. Nature Communications. 2019;10(1):1561.
- Dr Eleanor Sanderson - Dr Gareth Griffith -
Mendelian randomization (MR) uses genetic variants to estimate the causal effect of an exposure on an outcome of interest in a way that aims to overcome bias from unobserved confounding. The genetic variants used in MR are often selected as those most strongly associated with the exposure from a genome-wide association study (GWAS). These GWAS are conducted on datasets such as UK Biobank where many of the individuals are on medication such as blood pressure (BP) lowering medication. This medication use may bias effect estimates from GWAS studies or induce associations between SNPs for other characteristics and blood pressure, in turn biasing any MR studies which include BP as an exposure or an outcome.
It is not clear how to adjust for such bias in MR studies; excluding all individuals who report taking BP medication could induce selection bias as individuals taking medication will have had higher BP prior to medication use than those who do not. However, ignoring the potential issue is also likely to bias MR effect estimates. Alternative strategies include applying a BP adjustment to those reporting medication use to account for the effect of medication or restricting the sample to only younger individuals who are less likely to be taking medication.
The aim of this project is to explore how the different potential adjustments for medication use that could be applied to GWAS studies affect the results obtained from summary data MR analyses.
In this project the student will run GWAS on UK Biobank using the following adjustments to account for reported blood pressure medication
o Increasing the measured blood pressure by a set amount for those reporting medication use.
o Excluding those reporting medication use
o Restricting the sample to those under 50 where medication use is lower.
Each of these set of GWAS results will then be used in the same summary data MR analyses to compare the results obtained from the different adjustments. Separate MR analyses will be conducted with blood pressure as the exposure and the outcome. The results for each analysis will be compared to each other and to results with no adjustment for medication use to understand how these different adjustments bias the results from MR studies.
- Natalia Lewis - Dr Elizabeth Cook -
Intimate partner violence has a negative impact on social and economic outcomes. However, it has not been established how long those social and economic consequences last and how the duration varies with the type of violence. Duration of such effects is needed to cost the social and economic harms from violence.
To quantify the average length of time for which social and economic outcomes are affected by intimate partner violence, by type of violence (sexual, physical, emotional, financial).
A focused systematic review of studies reported in peer reviewed literature that recruited adults, had multiple time points, a social and/or economic outcome(s) and where intimate partner violence was a predictor, independent variable, or inclusion criterion.
Support will be provided by supervisors and subject librarian.
Training on quantitative evidence synthesis is available via short course and guided self-learning.
Patton SC, Szabo YZ, Newton TL. Mental and Physical Health Changes Following an Abusive Intimate Relationship: A Systematic Review of Longitudinal Studies. Trauma Violence Abuse. 2022 Oct;23(4):1079-1092. doi: 10.1177/1524838020985554. Epub 2021 Jan 20. PMID: 33468040.
Page, M.J., McKenzie, J.E., Bossuyt, P.M. et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. Syst Rev 10, 89 (2021). https://doi.org/10.1186/s13643-021-01626-4
- Dr Natalia Lewis - Professor Gene Feder -
Theory of change (programme theory) describes how an intervention can produce long-term outcomes through a logical sequence of intermediate outcomes. Theories of change have been widely used to design and evaluate health interventions. The development of a theory of change typically occurs through a co-production process, requiring stakeholders to reflect on how their programmes can bring change. There is comparatively little literature on applying a theory of change approach to multidisciplinary programmes of research addressing complex public health and clinical problems.
The Violence, Health, and Society (VISION) consortium is a 5-year UKPRP-funded multi-disciplinary collaboration which aims to improve the measurement of data on violence to influence policy and practice and reduce violence and the health inequalities that result. VISION worked with partner organisations and other professional stakeholders to co-produce theories of change for research strands within the consortium.
This study aims to evaluate the process of developing theories of change for research strands within the VISION consortium. The research questions are: 1) How were the theories of change co-produced? 2) What factors were important in facilitating or hindering the co-production?
This is a qualitative process evaluation with a case study comprising of participant observations of stakeholders’ workshops, analysis of physical artefacts and documents, semi-structured interviews with workshops attendees. Ethics approval for the study has been obtained. We will provide observation fieldnotes, artefacts, and documents. The student will conduct up to 20 semi-structured qualitative interviews with VISION researchers and stakeholders who took part in the development of theories of change. The interview topic guide will explore participants’ perspective on the stakeholders’ workshops on co-producing theories of change including any things which drew them to it initially, how they experienced it, what factors facilitated and hindered the process of theories development, and whether there are things that could have been done differently. Interviews will be audio recorded and professionally transcribed. The student will use the principles of co-production and framework approach for organising primary data into codes, candidate themes, and analytical themes.
1. Breuer et al 2016.Using theory of change to design and evaluate public health interventions: a systematic review. doi: 10.1186/s13012-016-0422-6.
2. Boblin et al 2013. Using Stake’s Qualitative Case Study Approach to Explore Implementation of Evidence-Based Practice. doi:10.1177/1049732313502128
- Dr Annie Herbert - Dr Laura Howe -
‘Selection bias’, a phenomenon that occurs when individuals in a study sample differ to that in the population of interest, is a huge problem across molecular, genetic, and life-course epidemiological studies. Most studies in this area rely on long-term cohort studies, to capture detailed prospective measurements on large samples of individuals, and for multiple generations. However, these studies often suffer from selection bias issues, first from the recruited sample being different to the general population, and then from loss-to-follow-up (drop-out or non-response) as the study continues, particularly by the time the second generation have become young adults. This selection bias is likely to bias estimates, for example, of prevalence, group differences, and intergenerational transmission, given that those who are most socioeconomically disadvantaged are less likely to be recruited and into cohort studies and are more likely to be lost.
Here, the effects of selection bias on estimates will be studied and accounted for in the established Avon Longitudinal Study of Parents & Children (ALSPAC) using an exemplar of domestic violence and abuse (‘DVA’, physical, sexual, financial, or psychological abuse, including controlling behaviours). Recent estimates in ALSPAC suggest around one-third of UK young adults experience DVA by the time they’re 21, the prevalence being higher for women than men (41% vs 29% victimised, 25% vs 20% perpetrated), and that certain groups of children who grow up around DVA (e.g. young males who grow up around physical violence) are at increased risk of violence and abuse within their own intimate relationships as they grow up (‘intergenerational transmission’). However, some estimates conflict with other literature (e.g. that perpetration is higher in women, or that there is no evidence for the detrimental impact of parental coercive control), and selection bias may play a large part in this.
This study aims to explore the extent to which estimates of prevalence and associations for DVA are sensitive to selection bias, and adjust estimates to account for it. The findings will be used to report more accurate estimates on DVA within the UK general population.
Objectives are to:
1. Compare characteristics between the general population (from general population statistics) with those of recruited mothers who did and did not report DVA during pregnancy.
2. Estimate the association between parental DVA during pregnancy and subsequent study loss-to-follow-up for mothers, their partners (where applicable), and the children.
3. Estimate the extent to which accounting for loss-to-follow-up affects statistics often reported in the DVA literature, such as DVA prevalence (including gender comparisons), and the association between parental DVA and young adult DVA (intergenerational transmission).
All analyses will be carried out in data on two generations of the Avon Longitudinal Study of Parents and Children (ALSPAC). Parent and ‘child’ (as a young adult) DVA variables have been previously defined in ALSPAC (captured at time-points from pregnancy until the young adult is age 21; Herbert et al, Wellcome Open Research 2020). Prevalence of parental and young adult DVA will be estimated (both overall and for separate DVA subtypes, such as psychological and physical), and binary logistic regressions will be fitted to estimate associations between parental and young adult DVA, adjusted for socio-economic indicators recorded during the mother’s pregnancy. These analyses will first be carried out on complete cases, and then again using i) multiple imputation to accounting for any missing data; ii) reweighting analyses using inverse probability treatment weighting. All analyses will be stratified by child gender.
By the end of the project, the student will have knowledge and skills in ALSPAC data, selection bias, regression analyses, multiple imputation, and inverse probability treatment weighting using the Stata or R programming package (depending on preference), as well as experience in interpreting study findings for public health. As the parental and young adult DVA variables have been characterised and studied in ALSPAC previously, we expect a large amount of work can be done, such that the finished work could feasibly be submitted to a relevant journal, such as Journal of Public Health, or Trauma, Violence & Abuse.
1. Marcus R Munafò, Kate Tilling, Amy E Taylor, David M Evans, George Davey Smith, Collider scope: when selection bias can substantially influence observed associations, International Journal of Epidemiology, Volume 47, Issue 1, February 2018, Pages 226–235, https://doi.org/10.1093/ije/dyx206
2. Howe LD, Tilling K, Galobardes B, Lawlor DA. Loss to follow-up in cohort studies: bias in estimates of socioeconomic inequalities. Epidemiology. 2013 Jan;24(1):1-9. doi: 10.1097/EDE.0b013e31827623b1. PMID: 23211345; PMCID: PMC5102324. DOI: 10.1097/EDE.0b013e31827623b1
3. Herbert A, Heron J, Barter C et al. Risk factors for intimate partner violence and abuse among adolescents and young adults: findings from a UK population-based cohort [version 3; peer review: 2 approved]. Wellcome Open Res 2021, 5:176 (https://doi.org/10.12688/wellcomeopenres.16106.3)
4. Haselschwerdt ML, Savasuk-Luxton R, Hlavaty K. A Methodological Review and Critique of the "Intergenerational Transmission of Violence" Literature. Trauma Violence Abuse. 2019 Apr;20(2):168-182. doi: 10.1177/1524838017692385. Epub 2017 Feb 13. PMID: 29333984.