Katusic, Slavica K.

Objective: To describe bullying experiences throughout childhood of people with and without childhood ADHD and co-occurring learning and psychiatric disorders from a population-based birth cohort. Methods: In a secondary data analysis of 199 childhood ADHD cases and 287 non-ADHD referents ( N = 486), reported experiences of peer interactions during elementary, middle, or high school were classified as “bully,” “victim,” “neither,” or “both.” Associations were assessed with multinomial logistic regression. Results: Adjusted for male sex, the odds of classification as victim-only, victim/bully, or bully- only (vs. neither) were 3.70 (2.36–5.81), 17.71, and 8.17 times higher for childhood ADHD cases compared to non-ADHD referents. Victim-bullies (62.5%) and bullies (64.3%) had both childhood ADHD and other psychiatric disorders versus 38.4% of victims-only and 17.3% of those classified as “neither.” Conclusion: The list of serious lifetime consequences of having ADHD also includes bullying. We offer future research directions for determining potential causal pathways.

Objective: To identify patterns (“classes”) of outcomes for adults with and without childhood ADHD. Method: Subjects were 232 childhood ADHD cases and 335 non-ADHD referents from a 1976 to 1982 birth cohort. We used latent class analyses to identify classes based on a broad array of adult psychosocial outcomes and determined the proportion of subjects with childhood ADHD within each class. Results: A three class solution provided optimal model fit; classes were termed “good,” “intermediate,” and “poor” functioning. Subjects with childhood ADHD comprised 62.8% of the “poor,” 53.5% of the “intermediate,” and 24.9% of the “good” functioning class. The “poor” functioning class was distinguished by increased likelihood of legal trouble and substance use disorders and included more individuals with childhood ADHD and psychiatric disorder than the “intermediate” class (45.5% vs. 30.6%). Conclusion: Children with ADHD are at risk for adverse adult outcomes in multiple domains and co-morbid childhood psychiatric disorders increase risk.

American Academy of Pediatrics (AAP) guidelines for children with Down syndrome (DS) include assessment for celiac disease (CD), although data to support this recommendation have been inconsistent. We determined the incidence of CD among children with DS in a population-based birth cohort of children born from 1976 to 2000 in Olmsted County, Minnesota. Individuals with karyotype-confirmed DS and CD (using diagnosis codes, positive serology, and duodenal biopsies) were identified. The incidence of CD in DS was compared with the published incidence of CD for Olmsted County residents (17.4 [95% confidence interval = 15.2-19.6] per 100 000 person-years). Among 45 individuals with DS from the birth cohort, 3 (6.7%) were identified with positive celiac serology and confirmatory biopsies at ages 9, 12, and 23 years, for an incidence of 325 per 100 000 person-years. Thus, individuals with DS have more than 18 times the incidence rate of CD compared with the general population, supporting the AAP guidelines.

We consider the problem of model‐based clustering in the presence of many correlated, mixed continuous, and discrete variables, some of which may have missing values. Discrete variables are treated with a latent continuous variable approach, and the Dirichlet process is used to construct a mixture model with an unknown number of components. Variable selection is also performed to identify the variables that are most influential for determining cluster membership. The work is motivated by the need to cluster patients thought to potentially have autism spectrum disorder on the basis of many cognitive and/or behavioral test scores. There are a modest number of patients (486) in the data set along with many (55) test score variables (many of which are discrete valued and/or missing). The goal of the work is to (1) cluster these patients into similar groups to help identify those with similar clinical presentation and (2) identify a sparse subset of tests that inform the clusters in order to eliminate unnecessary testing. The proposed approach compares very favorably with other methods via simulation of problems of this type. The results of the autism spectrum disorder analysis suggested 3 clusters to be most likely, while only 4 test scores had high (>0.5) posterior probability of being informative. This will result in much more efficient and informative testing. The need to cluster observations on the basis of many correlated, continuous/discrete variables with missing values is a common problem in the health sciences as well as in many other disciplines.

Abstract Background Few studies of how exposure of children to anesthesia may affect neurodevelopment employ comprehensive neuropsychological assessments. This study tested the hypothesis that exposure to multiple, but not single, procedures requiring anesthesia before age 3 yr is associated with adverse neurodevelopmental outcomes. Methods Unexposed, singly exposed, and multiply exposed children born in Olmsted County, Minnesota, from 1994 to 2007 were sampled using a propensity-guided approach and underwent neuropsychological testing at ages 8 to 12 or 15 to 20 yr. The primary outcome was the Full-Scale intelligence quotient standard score of the Wechsler Abbreviated Scale of Intelligence. Secondary outcomes included individual domains from a comprehensive neuropsychological assessment and parent reports. Results In total, 997 children completed testing (411, 380, and 206 unexposed, singly exposed, and multiply exposed, respectively). The primary outcome of intelligence quotient did not differ significantly according to exposure status; multiply exposed and singly exposed children scoring 1.3 points (95% CI, −3.8 to 1.2; P = 0.32) and 0.5 points (95% CI, −2.8 to 1.9; P = 0.70) lower than unexposed children, respectively. For secondary outcomes, processing speed and fine motor abilities were decreased in multiply but not singly exposed children; other domains did not differ. The parents of multiply exposed children reported increased problems related to executive function, behavior, and reading. Conclusions Anesthesia exposure before age 3 yr was not associated with deficits in the primary outcome of general intelligence. Although secondary outcomes must be interpreted cautiously, they suggest the hypothesis that multiple, but not single, exposures are associated with a pattern of changes in specific neuropsychological domains that is associated with behavioral and learning difficulties.

SummaryBackgroundUtilization of general anesthesia in children has important policy, economic, and healthcare delivery implications, yet there is little information regarding the epidemiology of these procedures in the United States.AimsThe primary objective of this study was to describe in a geographically defined population the incidence of procedures requiring general anesthesia up to the child's third birthday, and the patient characteristics associated with receiving these procedures. A secondary objective was to determine the proportion of children in the population who meet the risk criteria promulgated by the Food and Drug Administration (FDA).MethodsA retrospective cohort of children born from 1994 to 2007 in Olmsted County, MN was established. Birth certificate information and receipt of general anesthesia before age 3 were collected. Proportional hazard regressions were performed to evaluate the association between characteristics of children and incidence of general anesthesia.ResultsAmong the 20 922 children in the cohort, 3120 (14.9%) underwent at least 1 general anesthesia before age 3. In multivariate regression, factors independently associated with receiving at least 1 procedure included prematurity, male sex, lower birth weight, cesarean delivery, a non‐Hispanic mother, and a White mother, controlling for multiple gestation, number of children previously born, age, education, and marital status of the mother. Seven hundred and twenty‐three children (3.5%) had at least 1 subsequent procedure. Estimated gestational age <32 weeks and low birth weight were independently associated with receiving repeated anesthesia. Eight hundred and twenty children (3.9%) had a single prolonged exposure above 3 hours, multiple exposures prior to age 3, or both.ConclusionApproximately 1 in 7 children were exposed to at least 1 episode of general anesthesia before age 3, and approximately 1 in 4 children who received general anesthesia fall within the high‐risk category as defined by the recent FDA warning. The apparent disparities in surgical utilization related to race and ethnicity in this study population deserve further exploration.

Objective: The objective of this study was to evaluate the effect of psychiatric comorbidities on the association between childhood ADHD and suicidality among adults. Method: Subjects were recruited from a population-based birth cohort. Participating adult subjects with childhood ADHD and non-ADHD controls were administered a structured psychiatric interview to assess suicidality and psychiatric comorbidities. Associations were assessed using logistic regression. Results: Compared with controls, ADHD cases were significantly more likely to meet criteria for suicidality. Subjects with childhood ADHD who met criteria for generalized anxiety disorder had a higher than expected risk of suicidality with an observed odds ratio of 10.94 (95% confidence interval [4.97, 24.08]) compared with an expected odds ratio of 4.86, consistent with a synergistic interaction effect. Significant synergistic interactions were also observed for hypomanic episode and substance-related disorders. Conclusion: Childhood ADHD is significantly associated with adult suicidal risk. Comorbidity between ADHD and some psychiatric disorders is associated with a higher suicidal risk than expected.

Abstract Background Exposure of young animals to general anesthesia causes neurodegeneration and lasting behavioral abnormalities; whether these findings translate to children remains unclear. This study used a population-based birth cohort to test the hypothesis that multiple, but not single, exposures to procedures requiring general anesthesia before age 3 yr are associated with adverse neurodevelopmental outcomes. Methods A retrospective study cohort was assembled from children born in Olmsted County, Minnesota, from 1996 to 2000 (inclusive). Propensity matching selected children exposed and not exposed to general anesthesia before age 3 yr. Outcomes ascertained via medical and school records included learning disabilities, attention-deficit/hyperactivity disorder, and group-administered ability and achievement tests. Analysis methods included proportional hazard regression models and mixed linear models. Results For the 116 multiply exposed, 457 singly exposed, and 463 unexposed children analyzed, multiple, but not single, exposures were associated with an increased frequency of both learning disabilities and attention-deficit/hyperactivity disorder (hazard ratio for learning disabilities = 2.17 [95% CI, 1.32 to 3.59], unexposed as reference). Multiple exposures were associated with decreases in both cognitive ability and academic achievement. Single exposures were associated with modest decreases in reading and language achievement but not cognitive ability. Conclusions These findings in children anesthetized with modern techniques largely confirm those found in an older birth cohort and provide additional evidence that children with multiple exposures are more likely to develop adverse outcomes related to learning and attention. Although a robust association was observed, these data do not determine whether anesthesia per se is causal.