PubMed Health⌕ Search

Biomedical subjects

S A Petrill

Publications and source records attributed to S A Petrill.

13 recordsLinked to original sources
PubMed2000

One-year use and cost of inpatient and outpatient services among female and male patients with an eating disorder: evidence from a national database of health insurance claims.

OBJECTIVE: This study examined rates and cost of inpatient and outpatient treatment among 1,932 patients with an eating disorder. METHOD: One-year (1995) data were available through MarketScan, a national insurance database containing claims for 1,902,041 male patients and 2,005,760 female patients. RESULTS: Female patients (n = 1,756, 0.14% of all females) were significantly more likely to have been treated for an eating disorder than male patients (n = 176, 0.016% of all males), and females received more days of treatment than males. Outpatient treatment was the norm, regardless of gender or type of eating disorder. Average number of days (inpatient or outpatient) was less than the minimum recommended by standards of care. Age-adjusted costs for the treatment of anorexia nervosa and bulimia nervosa were comparable to the cost of treatment for schizophrenia. DISCUSSION: The utilization data are discussed in terms of barriers to care and treatment guidelines for eating disorders.

Adolescent↗
PubMed2000

Infant zygosity can be assigned by parental report questionnaire data.

A parental report questionnaire posted to a population sample of 18-month-old twins correctly assigned zygosity in 95%of cases when validated against zygosity determined by identity of polymorphic DNA markers. The questionnaire was as accurate when readministered at 3 years of age, with 96% of children being assigned the same zygosity on both occasions. The results validate the use of parental report questionnaire data to determine zygosity in infancy.

Chi-Square Distribution↗
PubMed1999

Genetic and environmental origins of verbal and performance components of cognitive delay in 2-year-olds.

The authors investigated the etiology of several measures of cognitive delay. Verbal (V) and performance (P) abilities were assessed in over 3,000 pairs of 2-year-old twins. Group-differences heritability for general delay (the lowest 5% of the V and P composite) was 35%. However, V and P delays considered independently showed large differences in group heritability (77% for V vs. 40% for P). Specific delays with comorbid cases eliminated showed an even greater difference in group heritability (78% vs. 22%, respectively). The small sample comorbid for both V and P delay also yielded high group heritability for both V (77%) and P (93%) scores. Shared environmental factors also differed in magnitude for V (20%) and P (41%) delays. Because the genetic and environmental origins of V and P delays in infancy differ, they are better considered separately rather than combined into a composite measure of general cognitive delay.

Child, Preschool↗
PubMed1998

Exploring the genetic and environmental etiology of high general cognitive ability in fourteen- to thirty-six-month-old twins.

Although numerous theories have attempted to explain the origins of high general cognitive ability (g), the genetic and environmental etiology of high g during infancy and early childhood has not previously been investigated. We report results of a twin study of high cognitive ability at 14, 20, 24, and 36 months using twins from the more than 600 children participating in the MacArthur Longitudinal Twin Study. High g groups were formed from the ninetieth percentile and above at each age, with IQ equivalent means at or above 126 across the ages. Results suggest increasing genetic influence and increasing genetic stability from 14 to 36 months using DeFries-Fulker multiple regression analyses. However, genetic influences are substantial when examining individuals who possess high g scores averaged across all 4 ages. These results suggest that, although high cognitive ability may be genetically influenced in early childhood, these influences differ in magnitude from 14 to 36 months.

Child Development↗
PubMed1997

Substantial genetic influence on cognitive abilities in twins 80 or more years old.

General and specific cognitive abilities were studied in intact Swedish same-sex twin pairs 80 or more years old for whom neither twin had major cognitive, sensory, or motor impairment. Resemblance for 110 identical twin pairs significantly exceeded resemblance for 130 fraternal same-sex twin pairs for all abilities. Maximum-likelihood model-fitting estimates of heritability were 62 percent for general cognitive ability, 55 percent for verbal ability, 32 percent for spatial ability, 62 percent for speed of processing, and 52 percent for memory. There was also evidence for the significant influence of idiosyncratic experience as the environmental component that most determines individual differences in cognitive abilities late in life.

Aged↗
PubMed1997

No association between general cognitive ability and the A1 allele of the D2 dopamine receptor gene.

Berman and Noble (1995) reported significantly reduced visuospatial performance in children with the TAQI A1 allele of the D2 dopamine receptor (DRD2) gene. Given that visuospatial performance loads highly on an unrotated principal component indexing general cognitive ability, we tested the association between DRD2 and WISC-R IQ comparing 51 high-IQ, 51 average-IQ, and 35 low-IQ children in the IQ Quantitative Trait Loci (QTL) Project. No statistically significant association between the TAQI A DRD2 alleles and IQ was found. Given that a statistically significant portion of genetic variance for specific cognitive abilities is independent of general cognitive ability, it is possible that the TAQI DRD2 association is specific to visuospatial performance and independent of general cognitive ability.

Adolescent↗
PubMed1997

Exploring the genetic etiology of low general cognitive ability from 14 to 36 months.

The genetic and environmental etiology of low general cognitive ability (g) during infancy and early childhood has not previously been investigated. The current study examined the genetic etiology of low cognitive ability at 14, 20, 24, and 36 months with twins from the MacArthur Longitudinal Twin Study. Low g groups were formed from the lowest 10th percentile at each age. Univariate probandwise concordance rates and DeFries-Fulker (J. C. DeFries & D. W. Fulker, 1985, 1988) multiple regression techniques suggest genetic etiology in low general cognitive ability groups. The stability of low general cognitive ability over time also appears to be primarily due to genetic factors. Although replication is necessary, these results suggest that the genetic etiology of low g during infancy and early childhood is at least as great as the heritability of g in the unselected population.

Aptitude↗
PubMed1996

The independent prediction of general intelligence by elementary cognitive tasks: genetic and environmental influences.

Current theories of intelligence have, in some cases, begun to include elementary cognitive tasks. Behavioral genetic studies of intelligence have not taken these theories into account. The current study includes 135 MZ and 128 DZ twin pairs from the Western Reserve Twin Project. The 11 WISC-R subtests as well as 6 elementary cognitive tasks were employed. Using a Schmid-Leiman (1957) transformation, analyses indicate a four-group factor model, supported by a second-order general factor at both phenotypic and biometric levels. Results indicate that the general factor, group factors, and specific residuals are necessary when examining additive genetic variance. Common environmental variance can be collapsed into a single general factor.

Adolescent↗
PubMed1995

The genetic and environmental variance underlying elementary cognitive tasks.

Although previous studies have examined the genetic and environmental influences upon general intelligence and specific cognitive abilities in school-age children, few studies have examined elementary cognitive tasks in this population. The current study included 149 MZ and 138 same-sex DZ twin pairs who participated in the Western Reserve Twin Project. Thirty measures from the Cognitive Abilities Test (CAT; Detterman, 1986) were studied. Results indicate that (1) these measures are reliable indicators of general intelligence in children and (2) the structure of genetic and environmental influences varies across measures. These results not only indicate that elementary cognitive tasks display heterogeneous genetic and environmental effects, but also may demonstrate that individual differences in biologically based processes are not necessarily due to genetic variance.

Adolescent↗
PubMed1995

Gender differences in language of AD patients: a longitudinal study.

We examined gender differences in probable Alzheimer's disease (AD) patients on language measures at four data collections (entry, 6, 12, and 18 months) and a normal elderly (NE) comparison group at entry and 18 months. Comparison of gender differences in language abilities of 60 (29 men, 31 women) early (Clinical Dementia Ratings I and II) AD subjects at entry revealed significant effects for gender on the Boston Naming Test (BNT) and Peabody Picture Vocabulary Test-Revised (PPVT-R) but not on the Word Fluency Test, shortened Token Test, or modified Reporter's Test. The 37 subjects (18 men, 19 women) who completed less than four data collection sessions compared with the 23 subjects (11 men, 12 women) who completed all four sessions differed on education and Reporter's Test scores. Longitudinal analysis of measures showed that gender differences persisted for the BNT and PPVT-R and that time differences were found on all measures. Gender differences remained after correcting for age, education, duration of illness, and mental status. We found no differences for the NE comparison group for gender or time. All AD subject trends were downward, suggesting that (1) language is affected over time in AD, (2) both men and women decline at similar rates, and (3) language abilities of women are more severely impaired at all time points.

Aged↗
PubMed1994

The heritability of memory in the Western Reserve Twin Project.

The heritability of memory ability was examined using 137 monozygotic and 127 same-sex dizygotic twin pairs from the Western Reserve Twin Project. Memory was assessed by eight measures drawn from the following batteries: the Wechsler Intelligence Scale for Children--Revised, the Colorado Test of Specific Cognitive Abilities, and the Cognitive Abilities Test. The results indicate that phenotypic correlations are generally low across these memory measures and heritability varies as a function of memory measure. These findings suggest that the heritability of memory varies as a function of the memory measure employed. Therefore, future studies investigating heritability estimates of memory should use a multimeasure battery to study this construct.

Adolescent↗
PubMed1993

The phenotypic and genetic relationships among measures of cognitive ability, temperament, and scholastic achievement.

The covariance among measures of cognitive ability, temperament, and scholastic achievement was examined in a subsample of 326 (89 Monozygotic, 74 Dizygotic) twins drawn from the Western Reserve Twin Project. Both phenotypic and behavioral genetic models were fit to the data. Univariate analyses indicate significant genetic influences on cognitive, achievement, and temperament variables. Common environmental influences also affected cognition and achievement but not temperament. Multivariate analyses indicate that both genetic and common environmental influences contribute to the covariance among all three variables. Cognition and achievement are highly genetically correlated. In contrast, achievement and temperament are highly correlated for common environmentality, while cognition and temperament are not.

Adolescent↗