George Leckie

• Managing Director at University of Bristol

Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA) is a multilevel regression modeling approach, rooted in intersectionality theory, for examining social inequalities across intersections of multiple social identities (e.g., gender, ethnicity, social class). Proponents argue that MAIHDA’s predicted intersectional m...

This study investigates intersectional disparities in experiencing three types of violence victimisation: stranger, acquaintance, and domestic, using five years of data from the Crime Survey for England and Wales (CSEW, N=165,661) and logistic intersectional Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA). Resul...

Sociodemographic inequalities in student achievement are a persistent concern for education systems and are increasingly recognized to be intersectional. Intersectionality considers the multidimensional nature of disadvantage, appreciating the interlocking social determinants which shape individual experience. Intersectional multilevel analysis of...

In England, students apply to universities using teacher-predicted grades instead of their final end-of-school A-level examination results. Predicted rather than achieved grades therefore determine how ambitiously students apply to and receive offers from the most selective courses. The Universities and Colleges Admissions Service (UCAS) encourages...

Intersectional multilevel analysis of individual heterogeneity and discriminatory accuracy (I-MAIHDA) is an innovative approach for investigating inequalities, including intersectional inequalities in health, disease, psychosocial, socioeconomic, and other outcomes. I-MAIHDA and related MAIHDA approaches have conceptual and methodological advantage...

Intersectional multilevel analysis of individual heterogeneity and discriminatory accuracy (I-MAIHDA) is an innovative approach for investigating inequalities, including intersectional inequalities in health, disease, psychosocial, socioeconomic, and other outcomes. I-MAIHDA and related MAIHDA approaches have conceptual and methodological advantage...

Intersectional multilevel analysis of individual heterogeneity and discriminatory accuracy (I-MAIHDA) is an innovative approach for investigating inequalities, including intersectional inequalities in health, disease, psychosocial, socioeconomic, and other outcomes. I-MAIHDA and related MAIHDA approaches have conceptual and methodological advantage...

Background The prevalence of teenage pregnancy in Colombia is higher than the worldwide average. The identification of socio-geographical disparities might help to prioritize public health interventions. Aim To describe variation in the probability of teenage maternity across geopolitical departments and socio-geographical intersectional strata in...

The intersectional Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA) approach is gaining prominence in health sciences and beyond, as a robust quantitative method for identifying intersectional inequalities in a range of individual outcomes. However, it has so far not been applied to longitudinal data, despite the...

School value-added models are widely applied to study, monitor, and hold schools to account for school differences in student learning. The traditional model is a mixed-effects linear regression of student current achievement on student prior achievement, background characteristics, and a school random intercept effect. The latter is referred to as...

Background In Sweden, as in many other countries, official monitoring of healthcare quality is mostly focused on geographical disparities in relation to a desirable benchmark. However, current evaluations could be improved by considering: (1) The intersection of other relevant axes of inequity like age, sex, income and migration status; and (2) The...

Social relations models allow the identification of cluster, actor, partner, and relationship effects when analysing clustered dyadic data on interactions between individuals or other units of analysis. We propose an extension of this model which handles longitudinal data and incorporates dynamic structure, where the response may be continuous, bin...

Sociodemographic inequalities in student achievement are a persistent concern for education systems and are increasingly recognized to be intersectional. Intersectionality considers the multidimensional nature of disadvantage, appreciating the interlocking social determinants which shape individual experience. Intersectional multilevel analysis of...

Background: Measuring multiple and higher-order interaction effects between multiple categorical variables proves challenging. Objectives: To illustrate a multilevel modelling approach to studying complex interactions. Methods: We apply a two-level random-intercept linear regression to a binary outcome for individuals (level-1) nested within s...

Ethnic achievement gaps are often explained in terms of student and school factors. The decomposition of these gaps into their within- and between-school components has therefore been applied as a strategy to quantify the overall influence of each set of factors. Three competing approaches have previously been proposed, but each is limited to the s...

Ethnic achievement gaps are often explained in terms of student and school factors. The decomposition of these gaps into their within- and between-school components has therefore been applied as a strategy to quantify the overall influence of each set of factors. Three competing approaches have previously been proposed, but each is limited to the s...

Moving school is a major event for students, with potential impacts on both student and school performance. Students can experience a diversity of move types, including variation in timing, origin and destination, though this complexity is not always acknowledged in studies or educational policies, which tend towards binary distinctions of movers v...

Increasing pupil mobility has led to widespread concern among parents, educators, and policymakers regarding its negative effects on academic performance. An important issue in examining mobility effects in longitudinal school achievement comparisons is providing accurate estimates. The presence of pupil mobility suggests that we should model pupil...

School accountability systems increasingly hold schools to account for their performances using value-added models purporting to measure the effects of schools on student learning. The most common approach is to fit a linear regression of student current achievement on student prior achievement, where the school effects are the school means of the...

School value-added models are widely applied to study the effects of schools on student achievement and to monitor and hold schools to account for their performances. The traditional model is a multilevel linear regression of student current achievement on student prior achievement, background characteristics, and a school random intercept effect....

Objectives From a reproductive justice framework, we aimed to investigate how a possible association between hormonal contraceptive (HC) and antidepressants use (as a proxy for depression) is distributed across intersectional strata in the population. We aimed to visualise how intersecting power dynamics may operate in combination with HC use to in...

Social cognition refers to a broad range of cognitive processes and skills that allow individuals to interact with and understand others, including a variety of skills from infancy through preschool and beyond, e.g., joint attention, imitation, and belief understanding. However, no measures examine socio-cognitive development from birth through pre...

School performance measures are published annually in England to hold schools to account and to support parental school choice. This article reviews and evaluates the ‘Progress 8’ secondary school accountability system for state‐funded schools. We assess the statistical strengths and weaknesses of Progress 8 relating to: choice of pupil outcome att...

School accountability systems increasingly hold schools to account for their performances using value-added models purporting to measure the effect of schools on student learning. The most common approach is to fit a linear regression of student current achievement on student prior achievement, where the school effects are the school means of the p...

Education systems around the world increasingly rely on school value-added models to monitor school performance and hold schools to account. These models typically focus on a limited number of academic outcomes. We explore how the traditional multilevel modelling approach to school value-added models can be extended to simultaneously analyse multip...

School performance measures are published annually in England to hold schools to account and to support parental school choice. This article reviews and evaluates the Progress 8 secondary school accountability system for state-funded schools. We assess the statistical strengths and weaknesses of Progress 8 relating to: choice of pupil outcome attai...

Families function best, and children benefit the most, when familial interactions are characterized by responsivity-an understanding and consideration of other people's thoughts and feelings. How responsive people are during interactions with others is a product of individual propensities, observed family norms, and unique relationship patterns, th...

Introduction Antidepressants are among the most commonly prescribed drugs in Sweden. However, we lack detailed knowledge on the socioeconomic and demographic distribution of antidepressant use in the population. To fill this gap, we performed an intersectional multilevel analysis of individual heterogeneity and discriminatory accuracy. Methods Ana...

This study develops and applies a framework for analyzing variability in individuals’ occupational prestige trajectories and changes in average variability between birth cohorts. It extends previous literature focused on typical patterns of intragenerational mobility over the life course to more fully examine intracohort differentiation. Analyses a...

Purpose Body dissatisfaction is common during adolescence and predicts poor psychological and physical health. Interventions have traditionally overrelied on delivery by external providers (e.g., researchers and psychologists), preventing scalability. This study evaluated the acceptability and effectiveness of a school-based body image intervention...

Objective To describe a novel strategy, Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA) to evaluate hospital performance, by analysing differences in 30-day mortality after a first-ever acute myocardial infarction (AMI) in Sweden. Design Cross-classified study. Setting 68 Swedish hospitals. Participants 43 24...

Within-individual variability of repeatedly-measured exposures may predict later outcomes: e.g. blood pressure (BP) variability (BPV) is an independent cardiovascular risk factor above and beyond mean BP. Since two-stage methods, known to introduce bias, are typically used to investigate such associations, we introduce a joint modelling approach, e...

We used Monte Carlo simulations to assess the performance of three bootstrap procedures for use with multilevel data (the parametric bootstrap, the residuals bootstrap, and the nonparametric bootstrap) for estimating the sampling variation of three measures of cluster variation and heterogeneity when using a multilevel logistic regression model: th...

Background: The conventional indicators of infant and under-five mortality are aggregate deaths occurring in the first year and the first five years, respectively. Monitoring deaths by <1 month (neonatal), 1-11 months (post-neonatal), and 12-59 months (child) can be more informative given various etiological causes that may require different inter...

Background While discontinuation of COPD maintenance medication is a known problem, the proportion of patients with discontinuation and its geographical and sociodemographic distribution are so far unknown in Sweden. Therefore, we analyse this question by applying an innovative approach called multilevel analysis of individual heterogeneity and dis...

The presence of randomly distributed measurement errors in scale scores such as those used in educational and behavioural assessments implies that careful adjustments are required to statistical model estimation procedures if inferences are required for ‘true’ as opposed to ‘observed’ relationships. In many cases this requires the use of external v...

Background One-year mortality after hip-fracture is a widely used outcome measure when comparing hospital care performance. However, traditional analyses do not explicitly consider the referral of patients to municipality care after just a few days of hospitalization. Furthermore, traditional analyses investigates hospital (or municipality) variati...

A first step when fitting multilevel models to continuous responses is to explore the degree of clustering in the data. Researchers fit variance-component models and then report the proportion of variation in the response that is due to systematic differences between clusters. Equally they report the response correlation between units within a clus...

This paper proposes an alternative educational accountability system for England that moves away from simplistic comparisons, or league tables, among schools towards a more nuanced reporting at a level of education authorities or other school groupings. Based upon the sampling of pupils within schools, it proposes the use of quantitative pupil asse...

Provider profiling entails comparing the performance of hospitals on indicators of quality of care. Many common indicators of healthcare quality are binary (eg, short-term mortality, use of appropriate medications). Typically, provider profiling examines the variation in each indicator in isolation across hospitals. We developed Bayesian multivaria...

Goldstein's Otto Wolff Lecture was delivered on 30 October 2019, on the date of his 80th birthday. Earlier that day, his colleagues Katie Harron, George Leckie, Bill Browne, James Carpenter and Fiona Steele gave talks about their work with him. Here, Tim Cole joins them to offer a brief retrospective on Goldstein's career Goldstein's Otto Wolff Lec...

Education systems around the world increasingly rely on school value-added models to hold schools to account. These models typically focus on a limited number of academic outcomes, failing to recognise the broader range of non-academic student outcomes, attitudes and behaviours to which schools contribute. We explore how the traditional multilevel...

The multilevel social relations model (SRM) is a commonly used statistical method for the analysis of social networks. In this article and accompanying supplemental materials, we demonstrate the estimation and interpretation of the SRM using Stat-JR software. Multiple software templates permit the analysis of different response types, including bin...

In England, Progress 8 is the Conservative government's headline secondary school performance and accountability measure. Progress 8 attempts to measure the average academic progress pupils make in each school between their KS2 tests and their GCSE Attainment 8 examinations. The Labour opposition recently announced they would scrap the KS2 tests we...

A first step when fitting multilevel models to continuous responses is to explore the degree of clustering in the data. Researchers fit variance-component models and then report the proportion of variation in the response that is due to systematic differences between clusters or equally the response correlation between units within a cluster. These...

[This corrects the article DOI: 10.1371/journal.pone.0220322.].

Within-individual variability of repeatedly-measured exposures may predict later outcomes: e.g. blood pressure (BP) variability (BPV) is an independent cardiovascular risk factor above and beyond mean BP. Since two-stage methods, known to introduce bias, are typically used to investigate such associations, we introduce a joint modelling approach, e...

Background In light of the opioid epidemic in the United States, there is growing concern about the use of opioids in Sweden as it may lead to misuse and overuse and, in turn, severe public health problems. However, little is known about the distribution of opioid use across different demographic and socioeconomic dimensions in the Swedish general...

Intersectional MAIHDA involves applying multilevel models in order to estimate intercategorical inequalities. The approach has been validated thus far using both simulations and empirical applications, and has numerous methodological and theoretical advantages over single-level approaches, including parsimony and reliability for analyzing high-dime...

This tutorial demonstrates the estimation and interpretation of the Multilevel Social Relations Model for dyadic data. The Social Relations Model is appropriate for data structures in which individuals appear multiple times as both the source and recipient of dyadic outcomes. Estimated using Stat-JR statistical software, the models are fitted to mu...

Background Thirty-day mortality after hip fracture is widely used when ranking hospital performance, but the reliability of such hospital ranking is seldom calculated. We aimed to quantify the variation in 30-day mortality across hospitals and to determine the hospital general contextual effect for understanding patient differences in 30-day mortal...

Background: Growth curve modelling such as trajectory analysis is useful for examining the longitudinal nature of depressive symptoms, their antecedents and later consequences. However, issues in interpretation associated with this methodology could hinder the translation from results to policy changes and interventions. The aim of this article is...

Multilevel models (mixed-effect models or hierarchical linear models) are now a standard approach to analysing clustered and longitudinal data in the social, behavioural and medical sciences. This review article focuses on multilevel linear regression models for continuous responses (outcomes or dependent variables). These models can be viewed as a...

Cross-classified multilevel modelling is an extension of standard multilevel modelling for non-hierarchical data that have cross-classified structures. Traditional multilevel models involve hierarchical data structures whereby lower level units such as students are nested within higher level units such as schools and where these higher level units...

Multiple membership multilevel models are an extension of standard multilevel models for non-hierarchical data that have multiple membership structures. Traditional multilevel models involve hierarchical data structures whereby lower-level units such as students are nested within higher-level units such as schools and where these higher-level units...

Importance Less favorable trajectories of depressive mood from adolescence to early adulthood are associated with current and later psychopathology, impaired educational attainment, and social dysfunction, yet the genetic and environmental risk factors associated with these trajectories are not fully established. Examining what risk factors are ass...

Dominant narratives of prescription opioid misuse (POM) in the U.S. have portrayed it as an issue primarily affecting White communities. In this study we explore POM as reported in data from the 2015 National Survey on Drug Use and Health, using an intersectional multilevel analysis of individual heterogeneity and discriminatory accuracy (MAIHDA)....

The epidemiological analysis of geographical inequalities in individual outcomes is a fundamental theme in public health research. However, many traditional studies focus on analysing area differences in averages outcomes, disregarding individual variation around such averages. In doing so, these studies may produce misleading information and lead...

Depression is a common mental illness and research has focused on late childhood and adolescence in an attempt to prevent or reduce later psychopathology and/or social impairments. It is important to establish and study population-averaged trajectories of depressive symptoms across adolescence as this could characterise specific changes in populati...

Objective: The present study investigates whether nurses working for a national medical telephone helpline show evidence of "decision fatigue," as measured by a shift from effortful to easier and more conservative decisions as the time since their last rest break increases. Method: In an observational, repeated-measures study, data from approxim...

In the UK, USA and elsewhere, school accountability systems increasingly compare schools using value‐added measures of school performance derived from pupil scores in high‐stakes standardised tests. Rather than naïvely comparing school average scores, which largely reflect school intake differences in prior attainment, these measures attempt to com...

Instrumental variables are often used to identify peer effects. This paper shows that instrumenting the \peer average outcome" with \peer average characteristics" requires the researcher to include the instrument at the individual level as an explanatory variable. We highlight the bias that occurs when failing to do this.

Recent social and educational policy debate in the UK has been strongly influenced by studies which have found children’s cognitive developmental trajectories to be significantly affected by the socio-economic status of the households into which they were born. Most notably, using data from the 1970 British cohort study, Feinstein (2003) concluded...

Many studies have demonstrated the existence of simple, unidimensional socioeconomic gradients in body mass index (BMI). However, in the present paper we move beyond such traditional analyses by simultaneously considering multiple demographic and socioeconomic dimensions. Using the Spanish National Health Survey 2011-2012, we apply inter-sectionali...

Many studies have demonstrated the existence of simple, unidimensional socioeconomic gradients in body mass index (BMI). However, in the present paper we move beyond such traditional analyses by simultaneously considering multiple demographic and socioeconomic dimensions. Using the Spanish National Health Survey 2011–2012, we apply intersectionalit...

Estimated differences between intersectional strata average BMI values and the overall population average BMI. Predicted strata effects from both models are sorted by values of model 1 from the lowest to the highest values. Values considered conclusive are specified with *. Shaded cells represent the minimum and maximum values of the predicted stra...

In the UK, US and elsewhere, school accountability systems increasingly compare schools using value-added measures of school performance derived from pupil scores in high-stakes standardised tests. Rather than naively comparing school average scores, which largely reflect school intake differences in prior attainment, these measures attempt to comp...

When using multilevel regression models that incorporate cluster-specific random effects, the Wald and the likelihood ratio (LR) tests are used for testing the null hypothesis that the variance of the random effects distribution is equal to zero. We conducted a series of Monte Carlo simulations to examine the effect of the number of clusters and th...

This paper proposes a novel multilevel gravity model of migration to study the under-researched topic of urban to urban migration in China. Many previous studies have looked at rural to urban migration in the context of urbanisation and economic development, and at return migration. Very few have looked at what is becoming more important in increas...

Pain is a bio-physiological phenomenon characterized by a circadian rhythm. A better understanding of diurnal variability in orthodontic pain perception would not only enhance our knowledge about how orthodontic pain intensity fluctuates over the 24-h day, but it also has a great potential to improve the clinical management of orthodontic pain. Sin...

To be relevant for public health, a context (e.g., neighborhood, school, hospital) should influence or affect the health status of the individuals included in it. The greater the influence of the shared context, the higher the correlation of subject outcomes within that context is likely to be. This intra-context or intra-class correlation is of su...

The present study examined the effects of socioeconomic status (SES) and sibling differences in birth weight on sibling differences in the receipt of maternal sensitivity (i.e., differential parenting). It was hypothesized that sibling differences in birth weight would predict absolute differential parenting across the sibship (i.e., the more diffe...

Since 1992, the UK Government has published so-called ‘school league tables’ summarizing the average attainment and progress made by students in each state-funded secondary school in England. In this article, we statistically critique and compare prominent past, current and forthcoming value-added and value-table measures of school performance. We...

Socioeconomic, ethnic and gender disparities in Chronic Obstructive Pulmonary Disease (COPD) risk are well established but no studies have applied multilevel analysis of individual heterogeneity and discriminatory accuracy (MAIHDA) within an intersectional framework to study this outcome. We study individuals at the first level of analysis and comb...

Existing studies have generally measured collective efficacy by combining survey respondents’ ratings of their local area into an overall summary for each neighborhood. Naturally, this results in a substantive focus on the variation in average levels of collective efficacy between neighborhoods. In this paper, we focus on the variation in consensus...

The traditional approach to estimating the consistency of school effects across subject areas and the stability of school effects across time is to fit separate value-added multilevel models to each subject or cohort and to correlate the resulting empirical Bayes predictions. We show that this gives biased correlations and these biases cannot be av...

Depression is a common mental illness associated with increased substance misuse and risk of suicide. Potential risk factors for depression include sex and depressive symptoms in early life, however the mechanisms responsible are not yet understood. Research has focused on late childhood and adolescence as this developmental period may be a modifia...

Multilevel data occur frequently in many research areas like health services research and epidemiology. A suitable way to analyze such data is through the use of multilevel regression models. These models incorporate cluster-specific random effects that allow one to partition the total variation in the outcome into between-cluster variation and bet...

Whether and how changes in economic circumstances or household income affect individuals’ diet and nutritional intakes is of substantial interest for policy purposes. This paper exploits a period of substantial income volatility in Russia to examine the extent to which, as well as how individuals protect their energy intakes in the face of unantici...

Aim To present a flexible model for repeated measures longitudinal growth data within individuals that allows trends over time to incorporate individual-specific random effects. These may reflect the timing of growth events and characterise within-individual variability which can be modelled as a function of age. Subjects and methods A Bayesian mo...