Semiparametric Group-based Modeling Research Articles

#5342 ASSOCIATION BETWEEN LONGITUDINAL GFR TRAJECTORIES AND BMD DECLINE RATE IN PATIENTS WITH CKD STAGE 2­–4

Abstract Background and Aims Bone mineral density (BMD) predicts fracture risk in patients with chronic kidney disease (CKD). However, there are few studies regarding BMD decline rates in CKD population. In this study, we investigated whether BMD decline rate is associated with baseline estimated glomerular filtration rate (eGFR) and further evaluated with longitudinal eGFR trajectories. Method A prospective cohort study of 1,006 patients with CKD stages 2 through 4 who enrolled in the KoreaN Cohort Study for Outcome in Patients With CKD between 2011 and 2016. BMD was measured using dual-energy X-ray absorptiometry at baseline and year 4. Estimated GFR was measured 2–5 times during 4 years of follow-up. Mixed linear regression model was used for the longitudinal analysis and trajectory analysis was performed using semiparametric group-based modeling using maximum likelihood. Results Declined renal function was associated with increased rate of decline in total hip BMD (Stage 2: −0.23, Stage 3A: −0.39, Stage 3B: −0.80, Stage 4: −1.20 in men; −0.86, −1.19, −1.20, −1.58% change/year respectively in women). Trajectory analysis revealed two distinct trajectories of eGFR for each CKD Stages 2 through 4: Class 1, stable group; Class 2, rapid decline group. Trajectory group that represented rapid eGFR decline showed consistent trends of increased rate of decline in total hip BMD. There was significant difference between stable and rapid decline group in Stage 3A, 3B (Stage 3A: −0.18 vs. −0.67 [p = 0.009], Stage 3B: −0.36 vs. −1.10 [p = 0.031] in men; Stage 3A: −0.79 vs. −1.67 [p = 0.006], Stage 3B: −0.60 vs. −1.52% change/year [p = 0.001] in women; p for interaction). Conclusion Declined renal function and faster GFR decline is associated with rapid BMD decline in CKD stage 2–4.

Testing stability of self-control over time among South Korean Youth using semi-parametric group-based modeling

Gottfredson and Hirschi argued the self-control theory in A General Theory of Crime (1990). Since then, many studies have examined the central proposition of low self-control as the cause of criminal behavior with cross-sectional data. However, few research studies have tested other stability propositions that low self-control is stable across the life-course and that once it is established at age 8 to 10, it remains relatively stable regardless of life changes. The purpose of this study was to examine stability postulate of the self-control theory. The current study used six-wave panel data of the Korean Children & Youth Panel Survey (KCYPS), which measured self-control of elementary school students at one year each of time points. The test of relative stability hypothesis comprises four analyses of data: correlations, individual change scores, SGM (Semi-parametric Group-based Modeling), and Multinomial Logistic Regression. Results revealed that the hypothesis of self-control stability was not strongly supported by the longitudinal data. Based on prior empirical research and this study’s finding, more research is needed to determine the stability of self-control.

Relations Between BMI Trajectories and Habitual Physical Activity Measured by a Smartwatch in the Electronic Cohort of the Framingham Heart Study: Cohort Study.

BackgroundThe prevalence of obesity is rising. Most previous studies that examined the relations between BMI and physical activity (PA) measured BMI at a single timepoint. The association between BMI trajectories and habitual PA remains unclear.ObjectiveThis study assesses the relations between BMI trajectories and habitual step-based PA among participants enrolled in the electronic cohort of the Framingham Heart Study (eFHS).MethodsWe used a semiparametric group-based modeling to identify BMI trajectories from eFHS participants who attended research examinations at the Framingham Research Center over 14 years. Daily steps were recorded from the smartwatch provided at examination 3. We excluded participants with <30 days or <5 hours of smartwatch wear data. We used generalized linear models to examine the association between BMI trajectories and daily step counts.ResultsWe identified 3 trajectory groups for the 837 eFHS participants (mean age 53 years; 57.8% [484/837] female). Group 1 included 292 participants whose BMI was stable (slope 0.005; P=.75), group 2 included 468 participants whose BMI increased slightly (slope 0.123; P<.001), and group 3 included 77 participants whose BMI increased greatly (slope 0.318; P<.001). The median follow-up period for step count was 516 days. Adjusting for age, sex, wear time, and cohort, participants in groups 2 and 3 took 422 (95% CI –823 to –21) and 1437 (95% CI –2084 to –790) fewer average daily steps, compared with participants in group 1. After adjusting for metabolic and social risk factors, group 2 took 382 (95% CI –773 to 10) and group 3 took 1120 (95% CI –1766 to –475) fewer steps, compared with group 1.ConclusionsIn this community-based eFHS, participants whose BMI trajectory increased greatly over time took significantly fewer steps, compared with participants with stable BMI trajectories. Our findings suggest that greater weight gain may correlate with lower levels of step-based physical activity.

The role of symptoms of psychopathy in persistent violence over the criminal career into full adulthood

Purpose: The extant criminal career literature supports the assertion that risk factors for violent and non-violent offending are the same. However, such studies have not examined the role of psychopathic personality disturbance (PPD) in the development of persistent violence across the life course. A situational action theory perspective was used to help illustrate the utility of PPD in explaining persistent violent offending. Methods: Convictions for violent offense and non-violent offenses were measured for Canadian male (n = 262) and female (n = 64) offenders at each year between ages 12 and 28. Semi-parametric group-based modeling was used to identify joint trajectories of violent and non-violent offending. Symptoms of adolescent PPD and other criminogenic risk factors were also measured. Results: Through the joint trajectory model, five violent and five non-violent trajectories were identified. PPD emerged as a strong predictor of membership in the trajectory associated with chronic violent offending but lower levels of non-violent offending. Conclusions: Contrary to earlier criminal career research, the most persistent violent offenders were not also involved in the highest rate of general offending. Theories that help explain why individuals are involved in persistent violence are needed. Incorporating PPD into such a theoretical framework appears necessary.

Psychopathic traits predict patterns of gun-carrying among a sample of justice-involved youth

In this study, distinct trajectories of gun-carrying were identified among a sample of juvenile justice-involved males (n = 1134) using semi-parametric group-based trajectory modeling. It was then examined if psychopathic traits as measured by the Youth Psychopathic Traits Inventory (YPI) were associated with group membership. Three trajectory groups were identified: “abstainers”, “desisting” and “late-starters”. Multinomial logistic regression models suggested that high scores on the Callous-Unemotional factor of the YPI increased the likelihood of being in the desisting group while high scores on the Grandiose-Manipulative factor of the YPI increased the likelihood of being in the late-starter group. These associations held controlling for several factors previously found to be associated with gun-carrying (i.e., age, gender, race/ethnicity, perceptions of gun accessibility, peer delinquency, prior delinquency, exposure to violence, neighborhood disorder, perceived rewards of crime, and gang involvement). These findings have important implications for understanding the facet-level associations of psychopathic traits and patterns of gun-carrying. The findings are particularly relevant considering the unique treatment profile for youth with elevated psychopathic traits.

Intersectional differences in serious violent victimization trajectories across the life course

There is substantial research regarding how individual demographic factors like race, gender, and class influence violent victimization risk, holding significant implications for short and long-term health outcomes. However, there remains limited insight into how intersectional identities shape victimization trajectories over time. This study draws on five waves of Add Health data to analyze how trajectories of violent victimization differ at the intersection of race/ethnicity and sex from adolescence through middle adulthood in the United States. We estimate longitudinal trajectories among six distinct groups using semi-parametric group-based trajectory models (GBTM). We find that Black men have the highest levels of violent victimization with the lowest likelihood of evading victimization. Black women experience especially high rates of chronic victimization that decreases over time, whereas persistent, low-level victimization is a unique classification among White women. Hispanic women are more likely to experience persistent, low-rate victimization compared to White and Black women. There are significant disparities in violent victimization across the life course among intersectional groups with the greatest burden falling on Black men and women. Future researchers should consider the long-term consequences of victimization trajectories through an intersectional lens.

Violent victimisation trajectories from adolescence through adulthood: consequences for sleep problems

BackgroundViolent victimisation is a stressful experience that has been linked with sleep problems among children, adolescents and adults. However, prior research has not assessed how victimisation trajectories across different stages...

Heterogeneity in trajectories of cybercriminals: A longitudinal analyses of web defacements

Longitudinal criminological studies greatly improved our understanding of the longitudinal patterns of criminality. These studies, however, focused almost exclusively on traditional types of offending and it is therefore unclear whether results are generalizable to online types of offending. This study attempted to identify the developmental trajectories of active hackers who perform web defacements. The data for this study consisted of 2,745,311 attacks performed by 66,553 hackers and reported to Zone-H between January 2010 and March 2017. Semi-parametric group-based trajectory models were used to distinguish six different groups of hackers based on the timing and frequency of their defacements. The results demonstrated some common relationships to traditional types of crime, as a small population of defacers accounted for the majority of defacements against websites. Additionally, the methods and targeting practices of defacers differed based on the frequency with which they performed defacements generally.

Abstract P116: Higher Body Mass Index Trajectories Are Associated With Lower Levels Of Physical Activity Measured By A Smartwatch

Introduction: The prevalence of obesity is rising. Most previous studies that examined the relationship between body mass index (BMI) and physical activity measured BMI at a single time-point, ignoring the time-varying nature of BMI. The relationship between BMI trajectories and habitual physical activity in community settings remains unclear. Objective: To assess the relationship between BMI trajectories and habitual physical activity measured by daily steps from a smartwatch, among participants enrolled in the electronic Framingham Heart Study (eFHS). We hypothesized that participants whose BMI trajectories increased over a 14-year period prior to the step assessment take fewer daily steps, compared to participants who maintained stable BMI trajectories during the same time period. Methods: We used a semiparametric group-based modelling method to identify BMI trajectory patterns. Participants who attended exams 1, 2, and 3 were included in building the trajectories. Daily steps were recorded from the smartwatch provided at exam 3 with “active days” defined as days with ≥ 5watch wear-hours. We excluded participants with &lt;30 active days. The median follow-up period for step count was 357 days (IQR: 467 days). We used generalized linear models that accounted for correlation between daily steps in the same individuals to examine the longitudinal relationship between BMI trajectory groups and daily step counts, adjusting for relevant covariates. Results: We identified three trajectory groups for the 837 eFHS participants. Group 1 included 292 participants (mean age 54 years, 57% women) whose BMI was stable (slope: 0.005, p=0.75); Group 2 included 468 participants (mean age 53 years, 56% women) whose BMI increased slightly (slope: 0.123, p&lt;9.2e-17); and Group 3 included 77 participants (mean age 50 years, 70% women) who had the largest increase of BMI (slope: 0.318, p=2.8e-22).Adjusting for age, sex, wear time and race/ethnicity, participants in group 3 (Δ1437 steps P&lt; 0.0001) and Group 2 (Δ422 steps, P=0.04) took significantly fewer steps, compared to participants in Group 1 (Model 1). The effect sizes were slightly attenuated but remained significant after additionally adjusting for hypertension, type 2 diabetes, current smoking, and cardiovascular disease: Group 3 took 1258 fewer steps, P=0.0001; Group 2 took 406 fewer steps, P=0.04 (Model 2). We further adjusted for sleep apnea, education, and marital status in Model 3 and observed that on average Group 3 took 1120 fewer steps (P= 0.0007) and Group 2 took 382 fewer steps (P= 0.06), compared to Group 1. Conclusion: Participants whose BMI trajectory increased over time took significantly fewer steps compared to participants with more stable BMI trajectories. Our findings suggest that levels of physical activity may correlate with greater weight gain during adulthood.

Symptom trajectories in the first 18 months and autism risk in a prospective high-risk cohort.

Although early autism spectrum disorder (ASD) detection strategies tend to focus on differences at a point in time, behavioral symptom trajectories may also be informative. Developmental trajectories of early signs of ASD were examined in younger siblings of children diagnosed with ASD (n = 499) and infants with no family history of ASD (n = 177). Participants were assessed using the Autism Observation Scale for Infants (AOSI) from 6 to 18 months. Diagnostic outcomes were determined at age 3 years blind to previous assessments. Semiparametric group-based modeling using AOSI scores identified three distinct trajectories: Group 1 ('Low', n = 435, 64.3%) was characterized by a low level and stable evolution of ASD signs, group 2 ('Intermediate', n = 180, 26.6%) had intermediate and stable levels, and group 3 ('Inclining', n = 61, 9.3%) had higher and progressively elevated levels of ASD signs. Among younger siblings, ASD rates at age 3 varied by trajectory of early signs and were highest in the Inclining group, membership in which was highly specific (94.5%) but poorly sensitive (28.5%) to ASD. Children with ASD assigned to the inclining trajectory had more severe symptoms at age 3, but developmental and adaptive functioning did not differ by trajectory membership. These prospective data emphasize variable early-onset patterns and the importance of a multipronged approach to early surveillance and screening for ASD.

Crime distortion within the NYPD: a potential method for estimating crime misclassification within CompStat statistics

ABSTRACT Since the advent of CompStat in 1994, the NYPD contends that felony crimes have decreased throughout NYC, specifically within the seven-major felony index crime categories. Previous work from Eterno and Silverman has suggested that the scope of the decrease was duplicitous and exaggerated due to the department's widespread practice of crime distortion. However, previous research has never attempted to quantify this phenomenon. This study addresses a critical gap within the existing CompStat literature by attempting to capture the magnitude of crime distortion. Using secondary crime data from the NYPD, the current study will examine burglaries and the suspected downward misclassifications, occurring within all NYC precincts, at the aggregate level, during the period between 2000 and 2013. The goals of this research are to identify and summarize any precinct-level patterns of potential crime distortion using semi-parametric group-based trajectory modeling and multinomial logistic regression techniques.

Seductions of Exposure Time: The Mismeasurement of Desistance among Persons Involved in Frequent and Serious Offending

Examining desistance has become an important part of the longitudinal examination of patterns of offending. Substantial attention has been given to defining desistance (e.g., as a process versus as an event), but less attention has been given to whether analytic strategies appropriately operationalize such definitions. The current study examines the prevalence of false desistance (i.e., wrongly concluding that a person has desisted) when semi-parametric group-based modelling is used. Data on 404 male and female participants followed from ages 12 to 35 as part of the Incarcerated Serious and Violent Young Offender Study were used to jointly model trajectories of convictions and trajectories of incarceration. The conviction model included incarceration as an exposure variable. Nevertheless, approximately 15% of desisters in this conviction model were characterized by false desistance. That is, their lack of continued convictions appeared to be due to involvement in serious crimes that resulted in lengthy periods of time incarcerated. This precluded opportunities to maintain their earlier levels of offending, even though their conviction trajectories were modelled taking incarceration into account. Joint trajectory modelling should be used to improve the detection of desistance and reliably evaluate the predictive validity of constructs hypothesized to influence desistance.

Maternal depression trajectories from 3 months to 11 years postpartum and offspring body composition in early adolescence.

To investigate the effect of maternal depressive symptom trajectories, from 3 months to 11 years postpartum, on the offspring's body composition at 11 years of age. Data from the Pelotas 2004 Birth Cohort, from the perinatal interview and from the 3-, 12-, 24- and 48-month and 6- and 11-year follow-ups. Community-based sample from the city of Pelotas, located in southern Brazil with approximately 350 000 inhabitants. The maternal depression symptom trajectories were identified through a semi-parametric group-based modelling approach, using the Edinburgh Postnatal Depression Scale (EPDS), with data from 3 months to 11 years postpartum. A total of 3467 (81·9 % of the total cohort). Five trajectory groups of EPDS scores were identified ('Low', 'Moderate low', 'Increasing', 'Decreasing' and 'Chronic high'). A total of 170 women (4·9 %) from the sample belonged to the 'Chronic high' group, having scored ≥13 EPDS points at every follow-up. Mean BMI in the 'Low' trajectory group was 0·77 (z-score 1·4), compared with 0·56 (z-score 1·4) in the 'Chronic high' group. Children from mothers in the 'Chronic high' group had lower fat mass (FM) (-1·34 ± 0·64 kg), FM% (-2·02 ± 0·85 percentage points) and FM index (-0·57 ± 0·27 kg/m2), compared with children from mothers in the 'Low' trajectory group. Adjusted analyses showed that sustained or transitory maternal depressive symptoms during childhood had no effect on the offspring's body composition indices at 11 years of age. Children raised by chronically depressed mothers have body composition indices at 11 years of age that are similar to those of children whose mothers have never been depressed.

Signalling Desistance? Crime Attitudes, Perceptions of Punishment, and Exposure to Criminogenic Models

To examine individual perceptions of the consequences of crime, the role of criminogenic models, and whether rational choice and criminal social capital are informative of desistance during emerging adulthood. Data from the Incarcerated Serious and Violent Young Offender Study were used to examine the relationship between different aspects of rational choice theories of desistance, criminogenic environment, and offending trajectories measured between ages 12 and 30, calculated using semi-parametric group-based modeling. Offending trajectories were then modeled using multinomial logistic regression. Trajectory analyses identified three desistance trajectories and three non-desistance trajectories. The strongest predictors of desistance trajectories included variables that relate to rational choices that considered the consequences of crime. Rational choice and life course perspectives on desistance as complementary, with sources of informal social control operating in a manner that, along with other factors, helps structure an individual’s consideration of, and importance placed on, the consequences of crime.

Trajectories of childhood adversity and the risk of depression in young adulthood: Results from the Avon Longitudinal Study of Parents and Children.

The significance of the timing and chronicity of childhood adversity for depression outcomes later in life is unclear. Identifying trajectories of adversity throughout childhood would allow classification of children according to the accumulation, timing, and persistence of adversity, and may provide unique insights into the risk of subsequent depression. Using data from the Avon Longitudinal Study of Parents and Children, we created a composite adversity score comprised of 10 prospectively assessed domains (e.g., violent victimization, inter-parental conflict, and financial hardship) for each of eighttime points from birth through age 11.5 years. We used semiparametric group-based trajectory modeling to derive childhood adversity trajectories and examined the association between childhood adversity and depression outcomes at the age of 18 years. Among 9,665 participants, five adversity trajectories were identified, representing stable-low levels (46.3%), stable-mild levels (37.1%), decreasing levels (8.9%), increasing levels (5.3%), and stable-high levels of adversity (2.5%) from birth through late childhood. Approximately 8% of the sample met criteria for probable depression at 18 years and the mean depression severity score was 3.20 (standard deviation = 3.95, range 0-21). The risk of depression in young adulthood was elevated in the decreasing (odds ratio [OR] = 1.72, 95% confidence interval [CI] = 1.19-2.48), increasing (OR = 1.81, 95% CI = 1.15-2.86), and stable-high (OR = 1.80, 95% CI = 1.00-3.23) adversity groups, compared to those with stable-low adversity, when adjusting for potential confounders. Children in trajectory groups characterized by moderate or high levels of adversity at some point in childhood exhibited consistently greater depression risk and depression severity, regardless of the timing of adversity.

Trajectories of maternal depressive and anxiety symptoms from pregnancy to five years postpartum and their prenatal predictors

BackgroundMaternal depression and anxiety have distinct constellations of symptom trajectories, which are associated with factors that may vary between different groups of women. The aim of this study was to identify subgroups of women who exhibit unique longitudinal trajectory patterns of depressive and anxiety symptoms from pregnancy to 5 years postpartum and the antenatal predictors associated with these maternal groups.MethodsThe study used a longitudinal data collected from 615 women in Saskatchewan from pregnancy to 5 years postpartum. Semiparametric group-based models were used to identify latent maternal depressive and anxiety trajectory groups. Multinomial logit models were then used to assess the association between maternal characteristics and the identified latent trajectory groups.ResultsWe identified four trajectory groups of maternal depressive symptoms: low-stable (35%); moderate-stable (54%); moderate-increasing (5%); and high-decreasing (6%), and three trajectory groups of maternal anxiety symptoms: very low-stable (13%); low-stable (58%); and moderate-stable (29%). We also identified several risk factors, most notably history of depression and stress, that were significantly associated with these trajectories.ConclusionHistory of depression and increased stress are significant risk factors that can be identified during regular perinatal visits; therefore, clinicians should inquire about these risk factors to identify women at high risk of ongoing depression or anxiety.

Measuring the Evolution of Radical Right-Wing Posting Behaviors Online

ABSTRACTResearchers have previously explored how right-wing extremists build a collective identity online by targeting their perceived “threat,” but little is known about how this “us” versus “them” dynamic evolves over time. This study uses a sentiment analysis-based algorithm that adapts criminal career measures, as well as semi-parametric group-based modeling, to evaluate how users’ anti-Semitic, anti-Black, and anti-LGBTQ posting behaviors develop on a sub-forum of the most conspicuous white supremacy forum. The results highlight the extent to which authors target their key adversaries over time, as well as the applicability of a criminal career approach in measuring radical posting trajectories online.

Trajectories of family poverty and children's mental health: Results from the Danish National Birth Cohort

Children exposed to socioeconomic adversity have elevated levels of psychological difficulties immediately and long-term. However, few studies have examined the consequences of long-term patterns of dynamic trajectories of family income. The Danish National Birth Cohort (DNBC) is a longitudinal, population-based birth cohort study (1996–2002). Data on household poverty from the year before birth until the child was 10 years of age (n = 12 measures) were obtained from the National Danish Registries and modeled using semiparametric group-based modeling. Child mental health symptoms were measured at 11 years using mother and child-reported Strengths and Difficulties Questionnaires (n = 40 192), and the child-reported Stress in Childhood (SiC) scale (n = 46 284). Four categories of family socioeconomic position were identified: 1) No poverty (83.5%); 2) Intermittent poverty, representing families who alternate between being above and below the poverty cut-off (8.6%); 3) Poverty during the perinatal period (4.9%); and 4) Chronic poverty (3.0%). Controlling for several early life characteristics of the family, mother and child, intermittent poverty vs. no poverty was consistently associated with child psychological difficulties (any problem: RR = 1.38, 95% CI: 1.16–1.64; conduct problems: RR = 1.38, 95% CI: 1.16–1.64; and stress: RR = 1.07, 95% CI: 1.02–1.12). An association was also found between perinatal poverty and children's symptoms of hyperactivity/inattention (RR = 1.28, 95% CI = 1.03; 1.59). We found no associations between chronic poverty and any of the outcome measures when adjusting for early life risk factors. Children growing up in households characterized by financial instability have elevated levels of psychosocial symptoms, especially externalizing behaviors, as well as stress in early adolescence.

Looking beyond the mean in grief trajectories: A prospective, population-based cohort study

BackgroundMost individuals adjust to the loss of a close person, but some experience adverse grief that challenges everyday life. No previous study has examined the development of grief symptoms in trajectories over time. We aimed to investigate trajectories of grief symptoms in bereaved partners and non-partners of severely ill patients starting before death until three years after death of the patient. MethodWe conducted a prospective population-based cohort study including 1138 partners and 597 non-partners of terminally ill patients. Participants completed the Prolonged Grief-13 scale pre-loss, six months post-loss, and three years post-loss. On this basis, we developed semi-parametric group-based trajectory models. Multinomial logistic regression models estimated, odds ratios (ORs) with 95% confidence intervals (CIs) between selected characteristics: age, gender, educational level, the patient's survival time, and types of grief trajectories. ResultsWe identified five specific grief trajectories for partners and four for non-partners. Low grief was identified in 34% of partners and 45% of non-partners, moderate/decreasing grief in 30% of partners and 31% of non-partners, high/decreasing grief in 20% of partners and 16% of non-partners, and high grief in 7% of partners and 8% of non-partners. In addition, a late grief trajectory was identified in 10% of partners. Low education compared to high education was associated with adverse grief trajectories (OR = 0.19 (95% CI = 0.80, 0.43) for partners following a high grief trajectory). ConclusionsThis study is the first to systematically describe specific trajectories of grief based on grief symptoms. The majority had a low or decreasing grief trajectory, whereas minor groups of partners and non-partners had a high grief trajectory, and a group of partners had a late grief trajectory. A consistent vulnerability factor was low education. Bereaved individuals may benefit from information on possible patterns of grief development, including adverse grief trajectories.

Developmental trajectories of adaptive behavior in autism spectrum disorder: a high‐risk sibling cohort

Children with autism spectrum disorder (ASD) often experience impairments in adaptive behavior. Developmental trajectories of adaptive behavior in ASD were examined in children from high-risk (siblings of children diagnosed with ASD, n=403) and low-risk (no family history of ASD, n=163) families. Children were assessed prospectively at 12, 18, 24, and 36months of age using the Vineland Adaptive Behavior Scales and underwent a blind independent diagnostic assessment for ASD at 36months of age. The semi-parametric group-based modeling approach using standard scores on the Adaptive Behavior Composite revealed three distinct developmental trajectories: (a) Group 1 (21.2% of sample) showed average performance at 12months and a declining trajectory; (b) Group 2 (52.8% of the sample) showed average performance at 12months with a slightly declining trajectory; and (c) Group 3 (26.0% of the sample) showed a higher level of adaptive behavior at 12months and a stable trajectory. The Mullen Scales of Early Learning Early Learning Composite and the Autism Observation Scale for Infants total score at 6 and 12months predicted trajectory membership. The results emphasize heterogeneous development associated with ASD and the need for interventions tailored to individual presentations.