Srinivasa Vittal Katikireddi

• BSc, MB ChB, MSc, MRCP, PhD, FFPH
• Fellow at University of Glasgow

Background Income is associated with many health outcomes, but it is unclear how far this reflects a causal relationship. Mendelian randomisation (MR) uses genetic variation between individuals to investigate causal effects and may overcome some of the confounding issues inherent in many observational study designs. Methods We used two-sample MR u...

Background Health guideline developers engage with interested people and groups to ensure that guidelines and their recommendations are relevant and useful to those who will be affected by them. These ‘interest‐holders’ include patients, payers/purchasers of health services, payers of health research, peer review editors, product makers, programme...

Background Socioeconomic inequality in infant mortality in the UK is rising. This study aims to identify contributory maternal and pregnancy factors that can explain the known association between area deprivation and infant mortality. Methods A cohort study was conducted using Clinical Practice Research Datalink (CPRD) primary care data between 20...

Introduction To estimate the effect of social media use in 14 year olds on risk of and inequalities in cigarette, e-cigarette, and dual use at 17 years, using the UK-representative Millennium Cohort Study (born 2000–2002). Aims and Methods The relationship of time spent on social media (using questionnaires [n = 8987] and time-use-diaries [n = 252...

Background Children from disadvantaged backgrounds are at greater risk of attention‐deficit hyperactivity disorder (ADHD)‐related symptoms, being diagnosed with ADHD, and being prescribed ADHD medications. We aimed to examine how inequalities manifest across the ‘patient journey’, from perceptions of impacts of ADHD symptoms on daily life, to the p...

Background Population mental health in the United Kingdom (UK) has deteriorated, alongside worsening socioeconomic conditions, over the last decade. Policies such as Universal Basic Income (UBI) have been suggested as an alternative economic approach to improve population mental health and reduce health inequalities. UBI may improve mental health (...

Policy Points Income is thought to impact a broad range of health outcomes. However, whether income inequality (how unequal the distribution of income is in a population) has an additional impact on health is extensively debated. Studies that use multilevel data, which have recently increased in popularity, are necessary to separate the contextual...

Objectives To examine the association between social media use and health risk behaviours in adolescents (defined as those 10-19 years). Design Systematic review and meta-analysis. Data sources EMBASE, Medline, APA PsycINFO, SocINDEX, CINAHL, SSRN, SocArXic, PsyArXiv, medRxiv, and Google Scholar (1 January 1997 to 6 June 2022). Methods Health ri...

Background Climate change is the most significant threat to public health and has important implications for mental health. As well as the direct impact from extreme weather events, existential worry about climate change, or ‘eco-anxiety’ may impact wellbeing. This study aims to assess levels of eco-anxiety across European countries and explore its...

Background Universal Basic Income (UBI) may improve mental health (MH), but no studies have trialled or modelled UBI in whole populations. We simulated the MH effects of UBI on UK working-age adults. Methods Adults aged 25-64 were simulated from 2022-26 with the SimPaths microsimulation model, using data from the UK Household Longitudinal Study. S...

Background To estimate the effect of social media use in 14 year olds on risk of and inequalities in alcohol use and binge drinking at 17 years. Methods Using the UK-representative Millennium Cohort Study, the relationship between time spent on social media (assessed using questionnaires [n = 8987] and time-use-diaries [n = 2520]) with frequency o...

Background Population mental health has deteriorated in many high-income countries over the last decade. Novel welfare policies such as Universal Basic Income (UBI) have been suggested as potential approaches to improve mental health. However, no studies have trialled or modelled UBI at a whole population level or considered impacts on mental healt...

Purpose The COVID-19 pandemic increased psychiatric distress and impacts differed by family structure. We aimed to identify mechanisms contributing to these inequalities. Methods Survey data were from the UK Household Longitudinal Study. Psychiatric distress (GHQ-12) was measured in April 2020 (first UK lockdown; n = 10,516), and January 2021 (loc...

Background: Administrative data offer unique opportunities for researching experiences which pose barriers to participation in primary research and household surveys. Experiencing multiple social disadvantages is associated with very poor health outcomes, but little is known about how often this occurs and what combinations are most common. We lin...

Background Addressing poverty through taxation or welfare policies is likely important for public mental health; however, few studies assess poverty’s effects using causal epidemiology. We estimated the effect of poverty on mental health. Methods We used data on working-age adults (25–64 years) from nine waves of the UK Household Longitudinal Surv...

Background: Employment and income are important determinants of mental health (MH), but the extent that unemployment effects are mediated by reduced income is unclear. We estimated the total effect (TE) of unemployment on MH and the controlled direct effect (CDE) not acting via income. Methods: We included adults 25-64 years from nine waves of t...

Linked administrative data offer a rich source of information that can be harnessed to describe patterns of disease, understand their causes and evaluate interventions. However, administrative data are primarily collected for operational reasons such as recording vital events for legal purposes, and planning, provision and monitoring of services. T...

Background Evidence on associations between COVID-19 illness and mental health is mixed. We aimed to examine whether COVID-19 is associated with deterioration in mental health while considering pre-pandemic mental health, time since infection, subgroup differences, and confirmation of infection via self-reported test and serology data. Methods We...

Background We estimated the effect of social media use on adolescents aged 14 years and risk of cigarette, e-cigarette, and dual use when aged 17 years. Data was from the UK Millennium Cohort Study, which followed up approximately 19 000 children born between 2000 and 2002. Methods Representative longitudinal data were collected at ages 14 and 17...

Background Employment and income are important determinants of mental health (MH), but the extent to which unemployment effects are mediated by reduced income is unclear. We estimated the total effect (TE) of unemployment on MH and the controlled direct effect (CDE) not acting via income. Methods We studied adults 25-64y from nine waves of the rep...

Background: Small area age- and sex-specific mortality rates are useful measures for population projections, health, economic, and social planning. Mortality rate estimation in small areas can be difficult due the low number of events/exposure. If a country’s mortality registration has problems, such as incomplete information, then estimating morta...

Objectives To investigate how guideline development groups collect and manage conflicts of interest (COI) when producing electronic cigarette (e-cigarette) recommendations. Study Design and Setting Public health bodies that had produced e-cigarette recommendations were identified from four purposively selected jurisdictions (WHO, UK, Australia, US...

Objectives Administrative data are primarily collected for operational processes and these processes can lead to sources of bias that may not be adequately considered by researchers. We provide a framework to help understand how biases might arise from using linked administrative data, and hopefully aid future study designs. ApproachWe developed th...

Background Homelessness, opioid dependence, justice involvement, and psychosis are each associated with an increased risk of poor health and commonly co-occur in the same individuals. Most existing studies of mortality associated with this co-occurrence rely on active follow-up methods prone to selection and retention bias, and focus on a limited s...

Background Lower incomes are associated with poorer mental health and wellbeing, but the extent to which income has a causal effect is debated. We aimed to synthesise evidence from studies measuring the impact of changes in individual and household income on mental health and wellbeing outcomes in working-age adults (aged 16–64 years). Methods For...

Background Evidence on associations between COVID-19 illness and mental health is mixed. We examined longitudinal associations between COVID-19 and mental health while considering: 1) pre-pandemic mental health, 2) time since infection; 3) subgroup differences; and 4) confirmation of infection via self-reported test, and serology data. Methods Usi...

This is the protocol for a Campbell systematic review. The objectives are as follows: to identify, describe, and summarize existing guidance and methods for multistakeholder engagement throughout the health guideline development process.

Gerry McCartney and colleagues argue for a new model of equitable, holistic, and sustainable public health should be central to recovery plans

Small relative effect sizes are common in observational studies of exposure in environmental and public health. However, such effects can still have considerable policy importance when the baseline rate of the health outcome is high, and many persons are exposed. Assessing the certainty of the evidence based on these effect sizes is challenging bec...

Background Income is thought to be a major determinant of mental health, but we believe this literature has not been quantitatively synthesised in its entirety. We systematically reviewed studies assessing the effect of income changes on mental health in working-age adults (16–64 years). Methods We searched seven databases (MEDLINE, Embase, Web of...

Background Social media might influence adolescents' perceived social norms and subsequent engagement in behaviours with potentially negative effects on health (health-risk behaviours). We systematically reviewed studies investigating the relationship between social media and health-risk behaviours in adolescents (age 10–19 years). Methods We sear...

Background Scotland was the first country to implement minimum unit pricing for alcohol nationally. Minimum unit pricing aims to reduce alcohol-related harms and to narrow health inequalities. Minimum unit pricing sets a minimum retail price based on alcohol content, targeting products preferentially consumed by high-risk drinkers. This study compr...

Background The relative importance of income, poverty and unemployment status for mental health is unclear, and understanding this has implications for income and welfare policy design. We aimed to assess the association between changes in these exposures and mental health. Methods We measured effects of three transition exposures between waves of...

Background Many population health research questions rely on observational data, where unmeasured confounding is a major source of bias. Sensitivity analyses for unmeasured confounding are increasingly applied, but often without sufficient consistency and transparency. We propose accessible recommendations to guide applied researchers in using two...

Background Vaccination is crucial to address the COVID-19 pandemic but inequalities in uptake may exacerbate existing health inequalities. We investigate the UK prevalence of COVID-19 vaccine hesitancy, identify which population subgroups are more likely to be vaccine hesitant, and report stated reasons for hesitancy. Methods Nationally representa...

Background Lower incomes are associated with poorer mental health (MH) and wellbeing, but the extent to which income has a causal effect (rather than reflecting reverse causation or confounding factors such as education) is debated. We synthesised evidence from studies measuring the impact of changes in individual or household incomes on MH and wel...

Background Social media (SM) may influence adolescents’ perceived social norms and subsequent health risk behaviours, although the evidence base around this is still developing. We conducted a systematic review of the relationship between SM and adolescent health risk behaviours: alcohol/tobacco/drug use, e-cigarettes, diet, physical activity, anti...

Background: This study aimed to study the association between shift work and incident and fatal cardiovascular disease (CVD), and to explore modifying and mediating factors. Methods: This is a population-based, prospective cohort study with a median follow-up of 11 years; 238 661 UK Biobank participants who were in paid employment or self-employ...

Objectives We aimed to review how ‘Risk of Bias In Non-randomised Studies–of Interventions’ (ROBINS-I), a Cochrane risk-of-bias assessment tool, has been used in recent systematic reviews. Study Design and Setting Database and citation searches were conducted in March 2020 to identify recently published reviews using ROBINS-I. Reported ROBINS-I as...

Background Unintentional injury is a leading cause of death/disability, with more disadvantaged children at greater risk. Understanding how inequalities vary by injury type, age, severity, and place of injury, can inform prevention. Methods For all Scotland-born children 2009-2013 (n=195,184), hospital admissions for unintentional injury (HAUI) we...

Background: Venous thromboembolism (VTE) is a common, life-threatening complication of COVID-19 infection. COVID-19 risk-prediction models include a history of venous thromboembolism. However, it is unclear whether remote history (>9 years previously) of VTE also confers increased risk of COVID-19. Objectives: To investigate possible association...

Background: Abdominal aortic aneurysm (AAA) can occur in patients who are ineligible for routine ultrasound screening. A simple AAA risk score was derived and compared to current guidelines used for ultrasound screening of AAA. Methods: UK Biobank participants without previous AAA were split into a derivation cohort (n=401,820, 54.6% women, mean ag...

Background: Household overcrowding is associated with increased risk of infectious diseases across cultures and countries. Limited data exist in England and Wales linking household overcrowding and risk of COVID-19. We used data collected from the Virus Watch cohort to examine the association between overcrowded households and infection to pandemic...

Centre-based childcare may benefit pre-school children and alleviate inequalities in early childhood development, but evidence on socio-emotional and physical health outcomes is limited. Data were from the UK Millennium Cohort Study (n=14,376). Inverse-probability weighting was used to estimate confounder-adjusted population-average effects of cent...

Background: Ethnicity can influence susceptibility to infection, as COVID-19 has shown. Few countries have systematically investigated ethnic variations in infection. Methods: We linked the Scotland 2001 Census, including ethnic group, to national databases of hospitalizations/deaths and serological diagnoses of bloodborne viruses for 2001-2013....

Background Social contact, including remote contact (by telephone, email, letter or text), could help reduce social inequalities in depressive symptoms and loneliness among older adults. Methods Data were from the 8th wave of the English Longitudinal Study of Aging (2016/17), stratified by age (n=1,578 aged <65; n=4,026 aged 65+). Inverse probabil...

Background Frailty has been associated with worse prognosis following COVID-19 infection. While several studies have reported the association between frailty and COVID-19 mortality or length of hospital stay, there have been no community-based studies on the association between frailty and risk of severe infection. Considering that different defini...

Introduction Older people have been reported to be at higher risk of COVID-19 mortality. This study explored the factors mediating this association and whether older age was associated with increased mortality risk in the absence of other risk factors. Methods In UK Biobank, a population cohort study, baseline data were linked to COVID-19 deaths....

Objectives We aimed to investigate demographic, lifestyle, socioeconomic and clinical risk factors for COVID-19, and compared them to risk factors for pneumonia and influenza in UK Biobank. Design Cohort study. Setting UK Biobank. Participants 49–83 year olds (in 2020) from a general population study. Main outcome measures Confirmed COVID-19 in...

Objective: To propose an approach for developing trustworthy recommendations as part of urgent responses (1-2 weeks) in the clinical, public health, and health systems fields. Study design and setting: We conducted a review of the literature, outlined a draft approach, refined the concept through iterative discussions, a workshop by the GRADE Rapi...

Objectives: The objective of the study is to present the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) conceptual approach to the assessment of certainty of evidence from modeling studies (i.e., certainty associated with model outputs). Study Design and Setting: Expert consultations and an international multidisciplinar...

Background: Overweight and obesity are increasing worldwide and are considered to be a major public health issue of the 21st century. Introducing taxation of the fat content in foods is considered a potentially powerful policy tool to reduce consumption of foods high in fat or saturated fat, or both. Objectives: To assess the effects of taxation...

Background Addressing the impact of poverty through income and welfare policies is likely important for public mental health; however, few studies assess potential effect size using causally-informed methodologies. To provide meaningful information for policymakers, we aimed to estimate the average treatment effect of transitioning into poverty on...

Welfare to work interventions seek to move out-of-work individuals from claiming unemployment benefits towards paid work. However, previous research has highlighted that for over-50s, particularly those with chronic health conditions, participation in such activities are less likely to result in a return to work. Using longitudinal semi-structured...

This briefing has been prepared by a working group focused on the implications for public health in Scotland of COVID-19’s impact on income, social security and the economy (see Appendix for membership). The purpose of this briefing is to highlight the significance of government support in promoting public health in Scotland by protecting income an...

Aims We examined the link between BMI and risk of a positive test for SARS-CoV-2 and risk of COVID-19-related death among UK Biobank participants. Methods Among 4855 participants tested for SARS-CoV-2 in hospital, 839 were positive and of these 189 died from COVID-19. Poisson models with penalised thin plate splines were run relating exposures of...

Background: Understanding of the role of ethnicity and socioeconomic position in the risk of developing SARS-CoV-2 infection is limited. We investigated this in the UK Biobank study. Methods: The UK Biobank study recruited 40-70-year-olds in 2006-2010 from the general population, collecting information about self-defined ethnicity and socioecono...

Background: Wealth inequalities are increasing in many countries, but their relationship to health is little studied. We investigated the association between individual wealth and mortality across the adult life course in Sweden. Methods: We studied the Swedish adult population using national registers. The amount of wealth tax paid in 1990 was...

Background: International and UK data suggest that Black, Asian and Minority Ethnic (BAME) groups are at increased risk of infection and death from COVID-19. We aimed to explore the risk of death in minority ethnic groups in England using data reported by NHS England. / Methods: We used NHS data on patients with a positive COVID-19 test who died in...

Objectives To investigate ethnic differences in falls and road traffic injuries (RTIs) in Scotland. Study design A retrospective cohort of 4.62 million people, linking the Scottish Census 2001, with self-reported ethnicity, to hospitalisation and death records for 2001–2013. Methods We selected cases with International Classification of Diseases–...

Background Global prevalence of overweight and obesity are alarming. For tackling this public health problem, preventive public health and policy actions are urgently needed. Some countries implemented food taxes in the past and some were subsequently abolished. Some countries, such as Norway, Hungary, Denmark, Bermuda, Dominica, St. Vincent and th...

Background: Stakeholder engagement has become widely accepted as a necessary component of guideline development and implementation. While frameworks for developing guidelines express the need for those potentially affected by guideline recommendations to be involved in their development, there is a lack of consensus on how this should be done in p...

Migrants suffer from worse psychological health than natives in many countries, yet the extent to which this varies by age at migration and duration of residence in the receiving context remains unexplored in Sweden. Drawing on a life course approach, we investigate differences in psychological distress by age at migration and duration of residence...

Background Globally, more than 2 million women are diagnosed with breast or cervical cancer every year. Depressive symptoms and personality traits have been implicated in cancer-related mortality, but the potential mechanisms through which these associations may operate are not well understood. We aimed to assess how depressive symptoms and neuroti...

In Scotland, like many other European countries, childhood immunization coverage is generally high, often exceeding levels typically required to achieve herd immunity (95%): uptake of the primary vaccines (excluding rotavirus) is ∼96% (at 12month(m)), with the 1st dose of measles, mumps and rubella (MMR) at 97% (by 5 years). However, the recommende...

Background Public health guidelines internationally aspire to be evidence based. However, different public health bodies have recommended adopting different approaches to e-cigarettes. While some have actively encouraged e-cigarette use, others have cautioned that e-cigarettes might introduce new health risks and renormalise tobacco smoking. We inv...

Background Some practitioners and researchers have advocated for greater attention to extreme health disadvantages associated with experiences of social exclusion (eg, homelessness, substance use, or imprisonment), which are not captured by conventional measures of socioeconomic position. It is therefore timely to examine whether such so-called inc...

Background A person's health might influence their ability to attend and concentrate at school, obtain, maintain, and be productive in employment, and maintain wellbeing and an active social life. We aimed to better understand the causal effects of health on social and socioeconomic outcomes, to help establish the broader benefits of investing in e...

Background: A cancer diagnosis can have a substantial impact on mental health and wellbeing. Depression and anxiety may hinder cancer treatment and recovery, as well as quality of life and survival. We argue that more research is needed to prevent and treat co-morbid depression and anxiety among people with cancer and that it requires greater clin...

Objectives: To estimate the causal effect of health conditions and risk factors on social and socioeconomic outcomes in UK Biobank. Evidence on socioeconomic impacts is important to understand because it can help governments, policy-makers and decision-makers allocate resources efficiently and effectively. Design: We used Mendelian randomization to...

Objective: To assess the cross-sectional and prospective associations between depressive symptoms, neuroticism and participation in breast and cervical screening in the UK. Methods: Women in the UK Biobank cohort with complete data who were eligible for breast cancer screening (aged 50-70 years, N=143 461) and/or cervical screening (<65 years, N...

In the recent decades, Brazil has outperformed comparable countries in its progress toward meeting the Millennium Development Goals. Many of these improvements have been driven by investments in health and social policies. In this article, we aim to identify potential impacts of austerity policies in Brazil on the chances of achieving the sustainab...

Background Attention-deficit hyperactivity disorder (ADHD) in childhood can have adverse effects on mental health, learning, and employment opportunities. There is evidence of a relationship between socioeconomic disadvantage and likelihood of ADHD in childhood; however, most studies use area-level measures which may underestimate inequality compar...

Background People with a history of homelessness, imprisonment, substance use, sex work, or serious mental illness experience much higher rates of ill-health and premature death than the general population. There is substantial overlap in these experiences in the population, and they may interact in important ways to influence health. However, the...

Background: Directed acyclic graphs (DAGs) are popular tools for identifying appropriate adjustment strategies for epidemiological analysis. However, a lack of direction on how to build them is problematic. As a solution, we propose using a combination of evidence synthesis strategies and causal inference principles to integrate the DAG-building e...

Introduction Scotland is the first country to carry out a national implementation of minimum unit pricing (MUP) for alcohol. MUP aims to reduce alcohol-related harms, which are high in Scotland compared with Western Europe, and to improve health equalities. MUP is a minimum retail price per unit of alcohol. That approach targets high-risk alcohol u...

Surveys are key means of obtaining policy-relevant information not available from routine sources. Bias arising from non-participation is typically handled by applying weights derived from limited socio-demographic characteristics. This approach neither captures nor adjusts for differences in health and related behaviours between participants and n...

Objective In politically contested health debates, stakeholders on both sides present arguments and evidence to influence public opinion and the political agenda. The present study aimed to examine whether stakeholders in the Soft Drinks Industry Levy (SDIL) debate sought to establish or undermine the acceptability of this policy through the news m...

Background People aged over 50 years form a growing proportion of the working age population, but are at increased risk of unemployment compared to other age groups. It is often difficult to return to work after unemployment, particularly for those with health issues. In this paper, we explored the perceptions, attitudes, and experiences of returni...

The last 6 years have seen sustained investment in health data science in the United Kingdom and beyond, which should result in a data science community that is inclusive of all stakeholders, working together to use data to benefit society through the improvement of public health and well‐being. However, opportunities made possible through the inno...

Background: Government policies can strongly influence migrants' health. Using a Health in All Policies approach, we systematically reviewed evidence on the impact of public policies outside of the health-care system on migrant health. Methods: We searched the PubMed, Embase, and Web of Science databases from Jan 1, 2000, to Sept 1, 2017, for quant...

Background Homelessness is associated with poor health. A policy approach aiming to end homelessness across Europe and North America, the ‘Housing First’ (HF) model, provides rapid housing, not conditional on abstinence from substance use. We aimed to systematically review the evidence from randomised controlled trials for the effects of HF on heal...