A performance-based method for early identification of medical students at risk of developing academic problems

The authors studied three classes at the Albert Einstein College of Medicine and found that students' performances on examinations administered during the third month (November) of medical school were highly predictive of their subsequent performances during the first two years of medical school. The investigation had two components: (1) a retrospective study of the classes of 1988 and 1989, which found that students' November grades from three first-year courses predicted 76% of the variance in the year-one weighted aggregate score and 41% for the year-two score, and (2) a prospective study of the class of 1992, in which three November of year one examination scores of the students in the lowest quarter of the class were highly predictive of their encountering substantial academic problems, with a sensitivity of .77 and a specificity of .99. This performance-based method was found to be more powerful than using the scores on the 1977 version of the Medical College Admission Test or the students' undergraduate grade-point averages, or both, in identifying individual students who were academically at risk.     

Is Infertility Associated with Childhood Autism?

Concerns persist about a possible link between infertility and risk of autism spectrum disorders (ASD). Interpretation of existing studies is limited by racial/ethnic homogeneity of study populations and other factors. Using a case–control design, we evaluated infertility history and treatment documented in medical records of members of Kaiser Permanente Northern California. Among singletons (349 cases, 1,847 controls), we found no evidence to support an increase in risk of ASD associated with infertility. Among multiple births (21 cases, 54 controls), we found an increased risk associated with infertility history and with infertility evaluations and treatment around the time of index pregnancy conception; however, small sample size and lack of detailed data on treatments preclude firm interpretation of results for multiple births.     

Birth defects monitoring in California: a resource for epidemiological research

Summary. The California Birth Defects Monitoring Program maintains a population-based birth defects registry of structural congenital malformations, monitoring over 600000 resident births annually. Cases are actively ascertained from hospitals and genetic centres throughout California and from selected facilities in adjacent states. Field staff identify presumptive cases from careful review of medical records. Diagnostic and demographic information is collected from in-patient and genetic centre medical charts for children diagnosed with major structural malformations between conception and 1 year of age. The application of these data to epidemiological investigations of birth defects is described in the context of prevalence studies, aetiological studies and evaluative studies, and the strengths and limitations of the registry data are discussed.     

Prenatal exposure to ��2-adrenergic receptor agonists and risk of autism spectrum disorders

This study aims to investigate the association between prenatal exposure to terbutaline and other β2 adrenergic receptor (B2AR) agonists and autism spectrum disorders (ASDs). The methodology used is a case–control study among children born from 1995 to 1999 at Kaiser Permanente Northern California hospitals. Cases (n = 291) were children with an ASD diagnosis; controls (n = 284) were children without ASDs, randomly sampled and frequency-matched to cases on sex, birth year, and delivery hospital. Exposure to B2AR agonists during 30 days prior to conception and each trimester of pregnancy was ascertained from prenatal medical records and health plan databases. The frequency of exposure to any B2AR agonist during pregnancy was similar for mothers of children with ASD and mothers of controls (18.9% vs. 14.8%, P = 0.19). Exposure to B2AR agonists other than terbutaline was not associated with an increased risk for ASDs. However, terbutaline exposure for >2 days during the third trimester was associated with more than a fourfold increased risk for ASDs independent of indication although the limited sample size resulted in an imprecise and nonsignificant effect estimate (OR_adj = 4.4; 95% confidence interval, 0.8–24.6). This analysis does not offer evidence linking B2AR exposure in pregnancy with autism risk. However, exposure to terbutaline during the third trimester for >2 days may be associated with an increased risk of autism. Should this result be confirmed in larger samples, it would point to late pregnancy as an etiologic window of interest in autism risk factor research.     

Regression in autism: prevalence and associated factors in the CHARGE Study.

OBJECTIVE: The aim of this study was to examine the prevalence of regressive autism and associated demographic, medical, and developmental factors by using 2 different definitions of regression based on the Autism Diagnostic Interview, Revised. METHODS: Subjects were aged 2 to 5 years, with autism (AU) or autism spectrum disorder (ASD) confirmed by standardized measures. Children with regression, defined as a) loss of both language and social skills or b) loss of either language or social skills, were compared with each other and to children with AU or ASD with no reported loss of skills on developmental and adaptive functioning. Parents reported on seizure, gastrointestinal, and sleep concerns. RESULTS: Fifteen percent (50/333) of the combined AU-ASD group lost both language and social skills; 41% (138/333) lost either language or social skills. No differences were found between the 2 samples of children with regression. Few developmental, demographic, or medical differences were found between the combined regression group and children without loss of skills, in both the larger AU-ASD sample and the more homogeneous AU-only sample. Children with regression had significantly lower communication scores than children without regression. CONCLUSIONS: The prevalence of regression in a large sample of young children with AU and ASD varies depending on the definition used; requiring loss of language significantly underestimates the frequency of developmental regression. Children with regression performed significantly less well than those without regression on 2 measures of communication, but the clinical meaningfulness of these differences is uncertain because of the small effect sizes.     

Evaluation of the hospital discharge diagnoses index and the birth certificate as sources of information on birth defects

The hospital discharge diagnoses index (DI) for newborns and the birth certificate were evaluated as sources of information about birth defects by comparing them with the same births in the case registry of the California Birth Defects Monitoring Program (CBDMP). The CBDMP is an active surveillance system; the staff visit hospitals to identify children with birth defects diagnosed in the first year of life. The study population comprised 66,481 live births to residents of five counties in the San Francisco Bay area in 1983. Of these infants, 2,543 had at least one birth defect noted on the DI, and 1,623 were in the CBDMP registry; 1,020 with defects noted on the DI were also in the CBDMP registry. For this same population, 399 infants had one or more defects noted on the birth certificate; 304 of these were also in the CBDMP registry. Reporting of birth defects on the birth certificate was poor for every condition. Reporting on the DI was most reliable for oral clefts and chromosomal defects; for these defects, the DI omitted one-third of the cases but had identified only about 10 percent false-positive (that is, unverified) cases. Major central nervous system malformations were less well reported, with about one-third of them false-positive. For all other birth defects, the DI either omitted more than half of the cases, or more than half of the cases reported were false-positive cases. These findings raise questions about the validity of analytic studies of birth defects if the data are obtained only from the DI or the birth certificate.     

Medical Conditions in the First Years of Life Associated with Future Diagnosis of ASD in Children

This study examines medical conditions diagnosed prior to the diagnosis of autism spectrum disorder (ASD). Using a matched case control design with 3911 ASD cases and 38,609 controls, we found that 38 out of 79 medical conditions were associated with increased ASD risk. Developmental delay, mental health, and neurology conditions had the strongest associations (ORs 2.0–23.3). Moderately strong associations were observed for nutrition, genetic, ear nose and throat, and sleep conditions (ORs 2.1–3.2). Using machine learning methods, we clustered children based on their medical conditions prior to ASD diagnosis and demonstrated ASD risk stratification. Our findings provide new evidence indicating that children with ASD have a disproportionate burden of certain medical conditions preceding ASD diagnosis.     

Candidate genes and risk for CP: a population-based study

Studies suggest that genetic polymorphisms may increase an individual's susceptibility to CP. Most findings have yet to be corroborated in an independent cohort. This case-control study is nested within all 334,333 infants ≥36 wk gestation born at Kaiser Permanente Medical Care Program, 1991-2002. We included only non-Hispanic whites who had a neonatal blood sample available. Case patients (n = 138) were identified from medical records to have spastic or dyskinetic CP. Controls (n = 165) were randomly selected from the population. We genotyped polymorphisms previously associated with CP: inducible NOS (iNOS)-231, apolipoprotein E (apoE) ε2 and ε4 alleles, TNF-α-308, IL-8 -251, lymphotoxin 60, endothelial NOS -922, endothelial protein C receptor 219, mannose-binding lectin 54 and 52, factor V Leiden, methyltetrahydrofolate reductase 1298 and 667, prothrombin 20210, and platelet activator inhibitor 11053. Similar to previous reports, the iNOS-231 T allele (25.7 versus 18.9%, p = 0.04) and the apoE ε4 allele (19.3 versus 13.2%, p = 0.04) were more common in patients with CP than in controls. However, there was no statistically significant association between any genetic polymorphism and CP after correction for multiple comparisons.