What Environments Support Reading Growth Among Current Compared With Former Reading Intervention Recipients? A Multilevel Analysis of Students and Their Schools.

School context can shape relative intervention response in myriad ways due to factors, such as instructional quality, resource allocation, peer effects, and correlations between the school context and characteristics of enrolled students (e.g., higher-poverty students attending higher-poverty schools). In the current study, we used data from 16,000 Grade 3 students in a community-based supplemental reading intervention program to investigate the degree to which school context factors (percentage eligible for free/reduced-price lunch [FRPL], school-level achievement) relate to the differences in triannual reading fluency growth rates between students actively receiving supplemental intervention (active recipients) and those that formerly received intervention (and therefore only received general class instruction at this time; former recipients). Using Bayesian multilevel modeling, our findings indicate that school-level FRPL eligibility played a more prominent factor in growth rate differences between these two groups than school-level reading achievement. However, school-level reading achievement was much more strongly related to reading fluency differences between active and former intervention recipients at the beginning of the school year (when controlling for FRPL). Implications for investigating school-level heterogeneity in intervention response and sustainability are discussed.

Social diversity and social cohesion in Britain.

We use data from a large-scale and nationally representative survey to examine whether there is in Britain a trade-off between social diversity and social cohesion. Using six separate measures of social cohesion (generalised trust, volunteering, giving to charity, inter-ethnic friendship, and two neighbourhood cohesion scales) and four measures of social diversity (ethnic fractionalisation, religious fractionalisation, percentage Muslim, and percentage foreign-born), we show that, net of individual covariates, there is a negative association between social diversity and most measures of social cohesion. But these associations largely disappear when neighbourhood deprivation is taken into account. These results are robust to alternative definitions of neighbourhood. We also investigate the possibility that the diversity--cohesion trade-off is found in more segregated neighbourhoods. But we find very little evidence to support that claim. Overall, it is material deprivation, not diversity, that undermines social cohesion.

Daily-level associations between posttraumatic stress disorder symptoms and reactions to retrieving positive autobiographical memories.

Trauma survivors with posttraumatic stress disorder (PTSD) report difficulties accessing and describing positive memories. To understand these patterns, we examined daily-level relations of PTSD symptoms with affective, cognitive (dwelling/rumination; pushing memory out of one's mind; suppression; avoidance; distraction; thinking about something else; remembering negative or positive memories/events; negative or positive thoughts; accepting or disapproving memory; reinterpreting memory), and behavioral (using alcohol/drugs; smoking cigarettes; cravings for or seeking out cigarettes/alcohol/drugs; craving, seeking out, or consuming large amounts of food; dissociation; engaging in risky behaviors; sharing memories; interference with ongoing task; arousal) reactions to retrieving positive memories. Eighty-eight trauma survivors (Mage= 39.89 years; 59.1% female) completed 7 daily measures of PTSD and reactions to retrieving positive memories. Days with more PTSD severity were associated with higher odds of same-day suppression, avoidance, distraction, thinking about something else, smoking cigarettes, craving substances, craving, seeking out, or consuming large amounts of food, dissociation, remembering negative memories/events/thoughts, engaging in risky behaviors, interference with ongoing tasks, and arousal (ORs=1.10-1.22); and greater negative affect (ß = 0.27). Supplemental lagged analyses indicated some associations between previous-day reactions to positive memory retrieval and next-day PTSD severity and vice versa. Trauma survivors with PTSD symptoms report negative and avoidance-oriented reactions to retrieving positive memories.

Incorporating uncertainty in Indigenous sea Country monitoring with Bayesian statistics: Towards more informed decision-making.

Partnerships in marine monitoring combining Traditional Ecological Knowledge and western science are developing globally to improve our understanding of temporal changes in ecological communities that better inform coastal management practices. A fuller communication between scientists and Indigenous partners about the limitations of monitoring results to identify change is essential to the impact of monitoring datasets on decision-making. Here we present a 5-year co-developed case study from a fish monitoring partnership in northwest Australia showing how uncertainty estimated by Bayesian models can be incorporated into monitoring management indicators. Our simulation approach revealed there was high uncertainty in detecting immediate change over the following monitoring year when translated to health performance indicators. Incorporating credibility estimates into health assessments added substantial information to monitoring trends, provided a deeper understanding of monitoring limitations and highlighted the importance of carefully selecting the way we evaluate management performance indicators.

Detecting Cohort Effects in Accelerated Longitudinal Designs Using Multilevel Models.

Accelerated longitudinal designs allow researchers to efficiently collect longitudinal data covering a time span much longer than the study duration. One important assumption of these designs is that each cohort (a group defined by their age of entry into the study) shares the same longitudinal trajectory. Although previous research has examined the impact of violating this assumption when each cohort is defined by a single age of entry, it is possible that each cohort is instead defined by a range of ages, such as groups that experience a particular historical event. In this paper we examined how including cohort membership in linear and quadratic multilevel models performed in detecting and controlling for cohort effects in this scenario. Using a Monte Carlo simulation study, we assessed the performance of this approach under conditions related to the number of cohorts, the overlap between cohorts, the strength of the cohort effect, the number of affected parameters, and the sample size. Our results indicate that models including a proxy variable for cohort membership based on age at study entry performed comparably to using true cohort membership in detecting cohort effects accurately and returning unbiased parameter estimates. This indicates that researchers can control for cohort effects even when true cohort membership is unknown.

How economic development affects healthcare access for people with disabilities: A multilevel study in China.

Meeting the healthcare needs of people with disabilities is an important challenge in achieving the central promise of "leave no one behind" during the Sustainable Development Goals era. In this study, we describe the accessibility of healthcare for people living with disabilities, as well as the potential influences of individuals' socioeconomic status and regional economic development. Our data covered 324 prefectural cities in China in 2019 and captured the access to healthcare services for people with disabilities. First, we used linear probability regression models to investigate the association between individual socioeconomic status, including residence, poverty status, education, and healthcare access. Second, we conducted an ecological analysis to test the association between prefectural economic indicators, including GDP (gross domestic product) per capita, urbanization ratio, average years of education, Engel's coefficient, and the overall prevalence of access to healthcare for people with disabilities within prefectures. Third, we used multilevel regression models to explore the association between the individual's socio-economic status, prefectural economic indicators, and access to healthcare at the individual level for people with disabilities. The results showed, first, that higher individual socioeconomic status (urban residence or higher educational level) was associated with better access to healthcare for people with disabilities. Second, regional economic indicators were positively associated with access to healthcare at the aggregate and individual levels. This study suggests that local governments, particularly in low- and middle-income countries, should promote economic development and conduct poverty alleviation policies to improve healthcare access for disadvantaged groups.

Investigating municipal and company influences on employment of people with chronic health conditions.

AIMS: In many countries, people with chronic health conditions have a weaker attachment to the labour market and fewer chances of re-employment. Much of the existing literature estimates the importance of institutional factors at the level of the municipality of residence or employer accommodation at the company level individually. This study examined the two levels simultaneously to disentangle the separate effects of municipal-level and of company-level factors. METHODS: Using full population data from Denmark, we estimated cross-classified multilevel models for people newly diagnosed with chronic conditions in 2010-2013 (more than 60,000 individuals in 20,000 companies). We tracked their employment outcomes for up to 5 years after diagnosis. RESULTS: The findings suggest that, in the short term, factors at the company level explain differences in the employment levels of individuals with chronic conditions more than institutional factors at the municipal level. A combination of average wage, company-level seniority, company size, and industry seem to explain much of company-level influence. In the longer term, the importance of company-level factors seemed to decline. Company-level factors explained blue collar workers' employment rates better than those of white collar workers, which is in line with the notion that blue collar workers expend more physical effort in their work so that they may be more reliant on company accommodation than white collar workers in the case of chronic conditions. CONCLUSIONS: Company-level factors affected the employment of persons newly diagnosed with chronic health conditions in the short term (in particular among workers in blue collar jobs), while municipal-level factors did not.

Emotions under control? Better cognitive control is associated with reduced negative emotionality but increased negative emotional reactivity within individuals.

Associations between impaired cognitive control and maladaptive emotion regulation have been extensively studied between individuals. However, it remains unclear if this relationship holds within individuals. In this study, we tested the assumption that momentary within-person fluctuation in cognitive control (working memory updating and response inhibition) is associated with emotional reactivity in everyday life. We conducted an experience sampling study (eight two-hourly prompts daily) where participants repeatedly performed short 2-back and Go/no-go tasks in daily life. We assessed negative and positive affective states, and unpleasantness of a recent event to capture emotional reactivity. We analyzed two overlapping samples: a Go/no-go and a 2-back dataset (N = 161/158). Our results showed that better momentary working memory updating was associated with decreased negative affect if the recent event was on average unpleasant for the given individual. However, better-than-average working memory updating in interaction with higher event-unpleasantness predicted higher negative affect levels (i.e., higher negative emotional reactivity). These findings may challenge the account of better cognitive control being universally related to adaptive emotion regulation. Although it is unlikely that emotional reactivity boosts working memory, future studies should establish the direction of causality.

Workers' emotional exhaustion and mental well-being over the COVID-19 pandemic: a Dynamic Structural Equation Modeling (DSEM) approach.

The COVID-19 pandemic has presented significant challenges to the workforce, particularly concerning emotional and mental well-being. Given the prolonged periods of work-related stress, unexpected organizational changes, and uncertainties about work faced during the pandemic, it becomes imperative to study occupational health constructs under a dynamic methodological perspective, to understand their stable and unstable characteristics better. In this study, drawing on the Dynamic Structural Equation Modeling (DSEM) framework, we used a combination of multilevel AR(1) models, Residual-DSEM (RDSEM), multilevel bivariate VAR(1) models, and multilevel location-scale models to investigate the autoregression, trend, and (residual) cross-lagged relationships between emotional exhaustion (EmEx) and mental well-being (MWB) over the COVID-19 pandemic. Data were collected weekly on 533 workers from Germany (91.18%) and Italy (8.82%) who completed a self-reported battery (total number of observations = 3,946). Consistent with our hypotheses, results were as follows: (a) regarding autoregression, the autoregressive component for both EmEx and MWB was positive and significant, as well as it was their associated between-level variability; (b) regarding trend, over time EmEx significantly increased, while MWB significantly declined, furthermore both changes had a significant between-level variability; (c) regarding the longitudinal bivariate (cross-lagged) relationships, EmEx and MWB negatively and significantly affected each other from week to week, furthermore both cross-lagged relationships showed to have significant between-level variance. Overall, our study pointed attention to the vicious cycle between EmEx and MWB, even after controlling for their autoregressive component and trend, and supported the utility of DSEM in occupational health psychology studies.

Sixteen-year trends in fruit consumption and related socioeconomic inequalities among adolescents in Western European countries.

PURPOSE: To investigate time trends in daily fruit consumption among Western European adolescents and in related socioeconomic inequalities. METHODS: We used nationally representative data from 18 countries participating in five rounds (2002 to 2018) of the cross-sectional "Health Behaviour in School-aged Children" (HBSC) survey (n = 458,973). The questionnaire, standardised across countries and rounds, was self-administered at school by 11-, 13- and 15-year-old adolescents. Daily fruit consumption was assessed using a short food frequency questionnaire (sFFQ). Socioeconomic inequalities were measured using the Family Affluence Scale (FAS). Multilevel logistic regressions were applied to study linear time trends in daily fruit consumption, overall, by country and by FAS. RESULTS: Between 2002 and 2018, daily fruit consumption increased in 10 countries (OR range, 1.04 to 1.13, p < 0.05) and decreased in 3 (OR range 0.96 to 0.98, p < 0.05). In all survey years combined, prevalence of daily fruit consumption was significantly higher among high FAS groups (42.6%) compared to medium (36.1%) and low FAS groups (31.7%; all countries: p < 0.001). Between 2002 and 2018, socioeconomic inequalities in fruit consumption increased in Austria, Germany, Italy, Netherlands, Scotland, Sweden, and Switzerland. Only in Norway FAS inequalities decreased while the prevalence increased. CONCLUSION: The prevalence of daily fruit consumption generally increased among adolescents between 2002 and 2018 in Western European countries, yet socioeconomic inequalities increased in some countries. Public health interventions should continue to promote fruit consumption with special attention to lower socioeconomic groups.

Intersectional inequities in the birthweight gap between twin and singleton births: A random effects MAIHDA analysis of 2012-2018 New York City birth data.

Birthweight is a widely-used biomarker of infant health, with inequities patterned intersectionally by maternal age, race/ethnicity, nativity/immigration status, and socioeconomic status in the United States. However, studies of birthweight inequities almost exclusively focus on singleton births, neglecting high-risk twin births. We address this gap using a large sample (N = 753,180) of birth records, obtained from the 2012-2018 New York City (NYC) Department of Health and Mental Hygiene, Bureau of Vital Statistics, representing 99% of all births registered in NYC, and a novel random coefficients intersectional MAIHDA (Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy) model. Our results show evidence of intersectional inequities in birthweight outcomes for both twin and singleton births by maternal age, race/ethnicity, education, and nativity status. Twins have considerably lower predicted birthweights than singletons overall (-930 g on average), and this is especially true for babies born to mothers who are younger (11-19 years), older (40+), racial/ethnic minoritized, foreign-born, and have lower education. However, the magnitude of this birthweight 'gap' between twins and singletons varies considerably across social identity strata, ranging between 830.8 g (observed among 40+ year old Black foreign-born mothers with high school degrees) and 1013.7 g (observed among 30-39 year old Hispanic/Latina foreign-born mothers with less than high school degrees). This study underscored the needs of a high-risk population and the need for aggressive social policies to address health inequities and dismantle intersectional systems of marginalization, oppression, and socioeconomic inequality. In addition to our substantive contributions, we add to the growing methods literature on intersectional quantitative analysis by demonstrating how to apply intersectional MAIHDA with random coefficients and random slopes. We conclude with a discussion of the significant potential for this methodological extension in future research on inequities.

Fast Multilevel Functional Principal Component Analysis.

We introduce fast multilevel functional principal component analysis (fast MFPCA), which scales up to high dimensional functional data measured at multiple visits. The new approach is orders of magnitude faster than and achieves comparable estimation accuracy with the original MFPCA (Di et al., 2009). Methods are motivated by the National Health and Nutritional Examination Survey (NHANES), which contains minute-level physical activity information of more than 10000 participants over multiple days and 1440 observations per day. While MFPCA takes more than five days to analyze these data, fast MFPCA takes less than five minutes. A theoretical study of the proposed method is also provided. The associated function mfpca.face() is available in the R package refund.

Understanding the Effects of COVID-19 on Child Maltreatment Reporting Among Rural Versus Urban Communities in the United States.

The onset of the coronavirus disease 2019 (COVID-19) pandemic impacted child protective services (CPS) reporting systems in the United States. It may have also led to widened gaps between rural and urban communities in child maltreatment (CM) report rates due to decreased interaction between children and mandated reporters especially in urban jurisdictions. Using data from the National Child Abuse and Neglect Data System, this study tests the hypothesis that during the onset of the COVID-19 pandemic, the decrease in CM reports made to CPS in urban counties was more pronounced than in rural counties. Reports of CM received by CPS offices between January 6, 2020 and June 28, 2020 were aggregated to per-county-per-week-per-10,000 children maltreatment report rates. We used changepoint analyses to analyze the inter- and intra-region incidence rate ratios among rural and urban counties. Moreover, we used multilevel random effects models to generate regression coefficients for the associations between rates of children with a maltreatment report, COVID-19 occurrence, rural-urban designation, and maltreatment risk factors. During the study period, rates of children with a maltreatment report among urban counties decreased more dramatically when compared with rural counties. Our findings persisted even with the inclusion of control variables associated with maltreatment risk factors. Social distancing restrictions may have had the unintended consequence of decreasing the visibility of at-risk children in urban counties more so than in rural counties. Considering geography is critical to continue to protect children during the COVID-19 pandemic and as we prepare for future disasters.

Developmental trajectories of anger and sadness dysregulation in childhood differentially predict later borderline symptoms.

Difficulties with emotion regulation are integral to borderline personality disorder (BPD) and its hypothesized developmental pathway. Here, we prospectively assess trajectories of emotion processing across childhood, how BPD symptoms impact these trajectories, and whether developmental changes are transdiagnostic or specific to BPD, as major depressive (MDD) and conduct disorders (CD) are also characterized by emotion regulation difficulties. This study included 187 children enriched for those with early symptoms of depression and disruptive behaviors from a longitudinal study. We created multilevel models of multiple components of emotional processing from mean ages 9.05 to 18.55 years, and assessed the effect of late adolescent BPD, MDD, and CD symptoms on these trajectories. Linear trajectories of coping with sadness and anger, and quadratic trajectories of dysregulated expressions of sadness and anger were transdiagnostic, but also exhibited independent relationships with BPD symptoms. Only inhibition of sadness was related to BPD symptoms. The quadratic trajectories of poor emotional awareness and emotional reluctance were also independently related to BPD. Findings support examining separable components of emotion processing across development as potential precursors to BPD, underscoring the importance of understanding these trajectories as not only a marker of potential risk but also potential targets for prevention and intervention.

Do regional labor market conditions matter for temporary work disability duration? A multilevel analysis of workers' compensation claims in five Canadian provinces.

BACKGROUND: Research has shown how regionally varying labor market conditions are associated with differences in work disability duration. However, the majority of these studies have not used multilevel models to appropriately account for the hierarchical clustering of individuals nested within contextual units (e.g., regions). Studies that have used multilevel models have focused on privately insured workers or on disability not specifically caused by work-related injury or illness. METHODS: Using claims data from five Canadian provincial workers' compensation systems, linear random-intercept models were used to estimate how much variance in temporary work disability duration ('work disability duration' for brevity) for work-related injuries and musculoskeletal disorders was due to differences between economic regions, what economic region-level labor market characteristics were associated with work disability duration, and what characteristics best explained economic region differences in work disability duration. RESULTS: Economic region characteristics, such as the unemployment rate and proportion of goods-producing employment, were independently associated with individual-level work disability duration. However, economic region variation only accounted for 1.5%-2% of total variation in work disability duration. The majority (71%) of economic region-level variation was explained by the provincial jurisdiction where the worker lived and was injured. Regional variation tended to be greater for female workers than males. CONCLUSIONS: The findings suggest that while regional labor market conditions matter for work disability duration, system-level differences in workers' compensation and health care are more important factors influencing work disability duration. Furthermore, while this study includes both temporary and permanent disability claims, the work disability duration measure only captures temporary disability.

Use of inhaled corticosteroids in preschool children and variability among pediatricians: a real-world analysis before and during the SARS-CoV-2 pandemic.

BACKGROUND: In Italy, inhaled corticosteroids (ICSs) are inappropriately prescribed to provide relief in URTI symptoms. Extreme variation in ICS prescribing has been described at regional and sub-regional level. During 2020, extraordinary containment measures were implemented in attempt to halt Coronavirus, such as social distancing, lockdown, and the use of mask. Our objectives were to evaluate the indirect impact of the SARS-CoV-2 pandemic on prescribing patterns of ICSs in preschool children and to estimate the prescribing variability among pediatricians before and during the pandemic. METHODS: In this real-world study, we enrolled all children residing in the Lazio region (Italy), aged 5 years or less during the period 2017-2020. The main outcome measures were the annual ICS prescription prevalence, and the variability in ICS prescribing, for each study year. Variability was expressed as Median Odds Ratios (MORs). If the MOR is 1.00, there is no variation between clusters (e.g., pediatricians). If there is considerable between-cluster variation, the MOR will be large. RESULTS: The study population consisted of 210,996 children, cared by 738 pediatricians located in the 46 local health districts (LHDs). Before the pandemic, the percentage of children exposed to ICS was almost stable, ranging from 27.3 to 29.1%. During the SARS-CoV-2 pandemic, the ICS prescription prevalence dropped to 17.0% (p < 0.001). In each study year, a relevant (p < 0.001) variability was detected among both LHDs and pediatricians working in the same LHD. However, the variability among individual pediatricians was always higher. In 2020, the MOR among pediatricians was 1.77 (95% CI: 1.71-1.83) whereas the MOR among LHDs was 1.29 (1.21-1.40). Furthermore, MORs remained stable over time, and no differences were detected in ICS prescription variability before and after pandemic outbreak. CONCLUSIONS: If on one hand the SARS-CoV-2 pandemic indirectly caused the reduction in ICS prescriptions, on the other the variability in ICS prescribing habits among both LHDs and pediatricians remained stable over the whole study time span (2017-2020), showing no differences between pre- pandemic and pandemic periods. The intra-regional drug prescribing variability underlines the lack of shared guidelines for appropriate ICS therapy in preschool children, and raises equity issues in access to optimal care.

The application of intersectional multilevel analysis of individual heterogeneity and discriminatory accuracy (MAIHDA) to examine birthweight inequities in New York City.

Exploring the intersection of dimensions of social identity is critical for understanding drivers of health inequities. We used multilevel analysis of individual heterogeneity and discriminatory accuracy (MAIHDA) to examine the intersection of age, race/ethnicity, education, and nativity status on infant birthweight among singleton births in New York City from 2012 to 2018 (N = 725,875). We found evidence of intersectional effects of various systems of oppression on birthweight inequities and identified U.S.-born Black women as having infants of lower-than-expected birthweights. The MAIHDA approach should be used to identify intersectional causes of health inequities and individuals affected most to develop policies and interventions redressing inequities.

[Age-specific regional characteristics of COVID-19 mortality in 2021]. / A COVID­19-halandóság életkor-specifikus regionális jellemzoi 2021-ben.

INTRODUCTION: In most countries, COVID-19 mortality increases exponentially with age, but the growth rate varies considerably between countries. The different progression of mortality may reflect differences in population health, the quality of health care or coding practices. OBJECTIVE: In this study, we investigated differences in age-specific county characteristics of COVID-19 mortality in the second year of the pandemic. METHOD: Age-specific patterns of COVID-19 adult mortality were estimated according to county level and sex using a Gompertz function with multilevel models. RESULTS: The Gompertz function is suitable for describing age patterns of COVID-19 adult mortality at county level. We did not find significant differences in the age progression of mortality between counties, but there were significant spatial differences in the level of mortality. The mortality level showed a relationship with socioeconomic and health care indicators with the expected sign, but with different strengths. DISCUSSION AND CONCLUSION: The COVID-19 pandemic in 2021 resulted in a decline in life expectancy in Hungary not seen since World War II. The study highlights the importance of healthcare in addition to social vulnerability. It also points out that understanding age patterns will help to mitigate the consequences of the epidemic. Orv Hetil. 2023; 164(17): 643-650.

Laparoscopic Sleeve Gastrectomy versus Laparoscopic Roux-en-Y Gastric Bypass: An Analysis of Weight Loss Using a Multilevel Mixed-Effects Linear Model.

BACKGROUND: Regarding weight loss outcomes, the results published after laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y (LRYGB) are conflicting. At this time, no clear evidence exists that outcomes from LSG are similar to those for LRYGB. The main objective of this study was to compare the percent of total weight loss (%TWL) between LRYGB and LSG over the first 2 years using a multilevel mixed-effects linear regression. METHODS: Data were collected from a prospectively maintained database of patients who underwent primary laparoscopic bariatric surgery from January 2016 to December 2017 at a French accredited bariatric center. The medical records of 435 consecutive patients were analyzed. %TWL was calculated at each follow-up surgical consultation and used as a repeated outcome variable in our models to assess the long-term %TWL. Due to this hierarchical structure of the data (%TWL at each visit = level 1) within patients (level 2), a multilevel linear regression adjusted for age, sex, preoperative BMI and comorbidities was used. RESULTS: Among the medical records of 435 consecutive patients included, 266 patients underwent LRYGB and 169 underwent LSG. The average %TWL at 2 years was 31.7% for the LRYGB group and 25.8% for the LSG group. The final multivariate model showed that, compared with LRYGB, LSG was associated with a decreased %TWL at over 2 years of follow-up (ß: -4.01; CI95%: -5.47 à -2.54; p ≤ 0.001). CONCLUSION: This observational study suggests that compared with LRYGB, LSG was associated with a decreased %TWL at 2 years using a multilevel model. Further studies are required to confirm the results observed with this statistical model.

The Effect of the Rate of Increase of Estrogen Replacement Therapy on Bone Mineral Density Accrual in Young Patients with Turner Syndrome.

BACKGROUND: Turner syndrome (TS) is caused by partial/complete X-chromosome monosomy with variable phenotypes, characterized by hypogonadism and short stature. To achieve pubertal changes, up to 50%-79% of patients with TS require estrogen replacement therapy (ERT), and 80% have low bone mineral density (BMD). Studies show that pubertal delays are associated with decreased BMD. Currently, guidelines suggest that ERT start at 12 years, increasing slowly, simulating pubertal progression. Many studies show that ERT increases BMD in adolescents with TS, but uncertainty remains as to how the rate of increase in ERT affects BMD. METHODS: Institutional review board approval was obtained from our institution for this retrospective chart review from 1991 to 2020. Charts were requested for the database using ICD 9-10 codes for TS and patients undergoing dual-energy X-ray absorptiometry. Biometric data and medical and treatment histories were extracted from charts. Multilevel random effects models were constructed to assess the time-dependent associations between ERT and bone density parameters. The primary independent variable of interest was the rate at which patients went from initiating ERT to reaching final doses. The primary dependent variables measured were total body BMD (tbBMD) and corresponding z-scores, calculated using dual-energy X-ray absorptiometry techniques. Analyses were done with SAS software (version 9.4, Cary, NC). RESULTS: Twenty-eight patients met the inclusion criteria. The mean age at TS diagnosis was 6.9 years; 8 patients had monosomy X, 16 had mosaic karyotypes, and 4 had unknown karyotypes. The average age for starting hormone replacement therapy was 14.1 years. Thirteen patients had spontaneous pubertal onset before starting hormone replacement therapy. tbBMD increased significantly with age (P = .03). However, change in BMD by age did not vary between patients who reached final adult doses of ERT within 0-2.5 years compared with patients who took 2.5-5.5 years (P = .7). Patients who took 2.5-5.5 years to reach final adult doses of ERT had a more negative trend in z-scores (-2.144) in comparison with patients who took 0-2.5 years (-1.776), although this difference did not reach statistical significance (P = .15). Future larger studies are needed to better understand the relationship between duration of ERT use and tbBMD. CONCLUSION: BMD in adolescents with TS increases with age. Neither absolute tbBMD values nor tbBMD z-scores increased faster when ERT doses were maximized within 2.5 years. This study identified a cohort of children under 12 years with TS who had not had any ERT or BMD measurements, a potential population for future larger prospective studies.