Hair dosimetry following neutron irradiation.

Use of hair as a biological dosimeter of neutron exposure was proposed a few years ago. To date, the (32)S(n,p)(32)P reaction in hair with a threshold of 2.5 MeV is the best choice to determine the fast neutron dose using body activation. This information is essential with regards to the heterogeneity of the neutron transfer to the organism. This is a very important parameter for individual dose reconstruction from the surface to the deeper tissues. This evaluation is essential to the adapted management of irradiated victims by specialized medical staff. Comparison exercises between clinical biochemistry laboratories from French sites (the CEA and COGEMA) and from the IRSN were carried out to validate the measurement of (32)P activity in hair and to improve the techniques used to perform this examination. Hair was placed on a phantom and was irradiated at different doses in the SILENE reactor (Valduc, France). Different parameters were tested: variation of hair type, minimum weight of hair sample, hair wash before measurement, delivery period of results, and different irradiation configurations. The results obtained in these comparison exercises by the different laboratories showed an excellent correlation. This allowed the assessment of a dose-activity relationship and confirmed the feasibility and the interest of (32)P measurement in hair following fast neutron irradiation.

DSM-IV internal construct validity: when a taxonomy meets data.

The use of DSM-IV based questionnaires in child psychopathology is on the increase. The internal construct validity of a DSM-IV based model of ADHD, CD, ODD, Generalised Anxiety, and Depression was investigated in 11 samples by confirmatory factor analysis. The factorial structure of these syndrome dimensions was supported by the data. However, the model did not meet absolute standards of good model fit. Two sources of error are discussed in detail: multidimensionality of syndrome scales, and the presence of many symptoms that are diagnostically ambiguous with regard to the targeted syndrome dimension. It is argued that measurement precision may be increased by more careful operationalisation of the symptoms in the questionnaire. Additional approaches towards improved conceptualisation of DSM-IV are briefly discussed. A sharper DSM-IV model may improve the accuracy of inferences based on scale scores and provide more precise research findings with regard to relations with variables external to the taxonomy.

Tri-ministry study: correlates of school-based parenting course utilization.

This study examined factors associated with the utilization of universally available school-based parent training. In a randomly selected, prospectively screened, unreferred community sample of 1,498 5- to 8-year-olds, 28% to 46% of families of children with high parent-reported externalizing problems enrolled. Externalizing problems, first-child status, and a high school education were associated with increased enrollment. Single-parent status, immigrant background, and limited extracurricular child activities were associated with lower enrollment. Economic disadvantage, stress, family dysfunction, and parental depressive symptoms were not associated with participation. Most families attributed nonparticipation to busy personal schedules, inconvenient times, and logistical difficulties.

Helping children adjust--a Tri-Ministry Study: I. Evaluation methodology.

This report describes the evaluation methodology of the Tri-Ministry Study--a school-based trial evaluating the effectiveness of three universal programs: (a) a classwide social skills program (SS), (b) a partner reading program (RE); and, (c) a combination of both (SS & RE), to reduce and prevent behavioural maladjustment among children in the primary division (up to grade 3) of Ontario schools. The trial was done between 1991 and 1995. Sixty schools in 11 boards of education took part and were assigned randomly to program(s) during the study. Contributing to the evaluation database are detailed follow-up assessments (observations, ratings, and standard tests) on 2439 children. Three-level growth trajectory models are used to evaluate program effects. The analysis presented for illustration in this report focuses on reading achievement measured by the Wide Range Achievement Test. A companion paper presents the results of the study and discusses important methodological and programmatic issues applicable to this and other prevention studies in the field.

Helping children adjust--a Tri-Ministry Study: II. Program effects.

This report describes program effects of the Tri-Ministry Study a school-based, longitudinal trial carried out over a 5-year period to assess the effectiveness of classwide social skills training (SS), partner reading (RE), and a combination of both (SS & RE) to reduce maladjustment among children in the primary division (up to grade 3) of Ontario schools. It also places these effects in the context of other school-based prevention studies and discusses them in view of important methodological and programmatic issues. The incremental effects attributable to the intervention programs were small and sporadic. There were statistically significant increases in prosocial behaviour observed in the playgrounds of intervention schools with no differentiation by program type. Furthermore, there was some evidence--a reduction in teacher and parent-rated externalising problems--that the combination of SS & RE and SS alone may have had modest beneficial effects. A review of nine other school-based studies, which evaluated universally delivered mental health prevention programs in general populations of students, revealed similar mixed results. There are both methodologic and programmatic issues implicated in the weak findings that have been reported to date. These issues need to be addressed to advance knowledge about the potential impact of mental-health prevention initiatives delivered universally through school-based programs. A companion paper gives the specific details on the programs, randomisation of schools, selection of subjects, measurements, and analysis.

Predicting conduct problems: can high-risk children be identified in kindergarten and grade 1?

Externalizing behavior symptoms (EBS) in childhood are a strong predictor of future conduct problems. This study evaluated their predictive accuracy using logistic regression and receiver operating characteristic curve techniques. EBS, alone and in combination with other child and familial risk factors, were used to predict conduct problems 30 months later in a nonclinic population of kindergartners and Grade 1 children. The sensitivity (Sn) and positive predictive value (PPV) of EBS alone were below preset criteria of > or = 50% for each (prevalence < or = 15%). Sn and PPV increased when other child and familial factors were combined with symptoms but did not exceed the preset criteria. From a developmental perspective, substantial stability of EBS exists over time. However, from the perspective of prevention science, significant levels of misclassification will occur when EBS are used to designate high-risk status under the low-prevalence conditions of normal populations.

What does early antisocial behaviour predict? A follow-up of 4- and 5-year-olds from the Ontario Child Health Study.

OBJECTIVE: To examine the predictive accuracy of antisocial behaviours among 4- and 5-year-old children for problem behaviours 4 years later (ages 8 and 9 years). METHOD: Data from the Ontario Child Health Study (1983) and Follow-up (1987) are used. Predictive accuracy is conceptualized using positive predictive value (PPV) and sensitivity. The predictive accuracy of early antisocial behaviors for the 1987 outcomes is examined overall, by gender, by variable thresholds of predictor and outcome be gender, and by using contextual variables alone or in combination with antisocial behaviour recorded in 1983. Resulting: The predictive accuracy of 1983 antisocial behaviour for 1987 outcome is generally modest and differs by gender (better for boys for externalizing disorder [PPV = 41%, sensitivity = 57%]; better for girls for internalizing disorder [PPV = 13%, sensitivity = 80%]; better for boys for conduct problems [PPV = 54%, sensitivity = 21%]¿. Using either gender-specific thresholds or gender-neutral thresholds does not alter predictive accuracy in a consistent way, nor does the use of a single contextual variable. Use of a cumulative risk index increases PPV but decreases sensitivity. CONCLUSION: The predictive accuracy of antisocial behaviour in 4-and 5-years-old children over 4 years in a nonclinical community population is limited. The clinical, research, and policy implications of this work are discussed.

Adequacy of interviews vs checklists for classifying childhood psychiatric disorder based on parent reports.

BACKGROUND: The advantages and disadvantages of lay-administered structured interviews and self-administered problem checklists for estimating prevalence and associated features of childhood psychiatric disorder have attracted little comment. This article compares the scientific adequacy of these 2 instruments for classifying DSM-III-R categories of childhood psychiatric disorder in general population samples. METHODS: Study data are from parental assessments of 251 children aged 6 to 16 years participating in a 2-stage measurement evaluation study. Reliability and validity were compared between the Diagnostic Interview for Children and Adolescents (the structured interview in the study) and the revised Ontario Child Health Study scales (the self-administered problem checklist used in the study). RESULTS: Reliability estimates based on the kappa statistic were comparable for the 2 instruments and ranged from 0.21 (conduct disorder) to 0.70 (depression) on the lay interview and from 0.17 (depression) to 0.61 (oppositional defiant disorder) on the self-administered checklist. Validity coefficients tended to favor the checklist categories, but only marginally. CONCLUSIONS: On balance, differences in reliability and validity were small between the 2 instruments. These differences would appear to have no discernible impact on the knowledge about prevalence and associated features of disorder generated by use of such instruments in general population surveys.

Prevalence of child physical and sexual abuse in the community. Results from the Ontario Health Supplement.

CONTEXT: Although child maltreatment is considered common, few community surveys have examined the prevalence of more than 1 type of maltreatment among both males and females. OBJECTIVE: To determine the prevalence of a history of physical and sexual abuse during childhood among the general population. DESIGN: General population survey. SETTING: Household dwellings in the province of Ontario, Canada. PARTICIPANTS: A random sample (N=9953) of residents aged 15 years and older participated in the Ontario Health Supplement. MAIN OUTCOME MEASURE: Self-administered questionnaire about a history of physical and sexual abuse in childhood. RESULTS: A history of child physical abuse was reported more often by males (31.2%) than females (21.1%), while sexual abuse during childhood was more commonly reported by females (12.8%) than males (4.3%). Severe physical abuse was reported by similar proportions of males (10.7%) and females (9.2%). A greater percentage of females reported a history of severe sexual abuse (11.1%) compared with males (3.9%). Age of the respondent was not significantly associated with childhood abuse within any category for males. However, for females, the reported prevalence in childhood of sexual abuse, co-occurrence of physical and sexual abuse, and both categories of severe abuse decreased with increasing age of the respondent. CONCLUSIONS: A history of childhood maltreatment among Ontario residents is common. Child abuse may be more prevalent in younger women compared with older women, or there may be a greater willingness among younger women to report abuse.

Identifying thresholds for classifying childhood psychiatric disorder: issues and prospects.

OBJECTIVE: To evaluate empirically the implications of choosing different thresholds to classify conduct disorder and attention-deficit hyperactivity disorder for estimating prevalence, test-retest reliability of measurement, and informant (parent/teacher) agreement and for evaluating comorbidity and associated features of disorder. METHOD: Data for the study came from problem checklist assessments done by parents and teachers of children aged 6 to 16 years (N = 1,229) selected with known probability from a general population sample and from structured interviews obtained in a stratified, random subsample (n = 251). RESULTS: Estimates varied widely depending on the rationale used to set thresholds. Percent prevalence went from 0.1 to 39.2; kappa estimates of test-retest reliability went from .19 to .82. Parent-teacher agreement based on kappa went from .0 to .38. Relative odds between disorder and associated features varied twofold. CONCLUSION: Use of different rationales to set thresholds for classifying childhood psychiatric disorder in the general population has profound implications for what we learn about the epidemiology of childhood disorder.

Mental health supplement to the Ontario Health Survey: methodology.

OBJECTIVE: To describe the methodology of a province-wide, cross-sectional, epidemiologic study of psychiatric disorder among those aged 15 years and over living in household dwellings in Ontario. METHOD: Respondents for the survey were drawn from households (N = 13002) participating in a province-wide health survey. One person per household was selected, and 9953 (76.5%) participated. RESULTS: Participants and nonparticipants were similar to each other. An extensive array of data, including measures of psychiatric disorder classified using a revised version of the Composite International Diagnostic Interview (CIDI), are available for all respondents. CONCLUSIONS: The Ontario Health Supplement is contained in a public-use data file at the Ontario Ministry of Health and is available to investigators for study. A strong survey design, careful measurement, and acceptable levels of response provide the rationale for our inviting researchers to access and use the Ontario Health Supplement data base.

One-year prevalence of psychiatric disorder in Ontarians 15 to 64 years of age.

OBJECTIVE: To present the one-year prevalence of 14 psychiatric disorders in a community sample of Ontarians aged 15 to 64 years. METHOD: Data on psychiatric disorders were collected on 9953 respondents using the University of Michigan revision of the Composite International Diagnostic Interview (UM-CIDI). DSM-III-R criteria were used to define the psychiatric disorders. RESULTS: Almost 1 in 5 Ontarians (18.6%) had one or more of the disorders measured in the survey. Among 15-to 24-year-olds, 1 in 4 was affected. The distribution of individual disorders varied by sex and age. CONCLUSION: Because of the immense burden of suffering associated with psychiatric disorders, clinical and research efforts in this area should receive high priority within the health budget.

Integrating assessment data from multiple informants.

OBJECTIVE: To examine the consequences for measurement of child psychiatric disorder (conduct and oppositional disorders) of not integrating the data on the same individual from different informants compared with integrating the information from parents and teachers, using three different strategies. METHOD: Data for the study came from problem checklist assessments done by parents and teachers of children aged 6 to 16 years (N = 1,134) selected with known probability from a general population sample and from structured interviews obtained in a stratified random subsample (n = 251). RESULTS: As expected, parent-teacher agreement was low. The pattern of associated features of disorder was found to vary markedly in parent-identified compared with teacher-identified disorder. Furthermore, combining informants had the disadvantage of masking the distinctive patterns of associated features noted in informant-specific disorders. Finally, by treating disorder as informant-specific, the internal properties of the measure are not generally inferior to those obtained by combining informants in various ways. CONCLUSION: Child psychiatric disorders should be conceptualized as informant-specific phenomena.

Factors predicting use of mental health and social services by children 6-16 years old: findings from the Ontario Child Health Study.

Correlates of mental health and social service utilization are examined based on Ontario Child Health Study data. Findings indicate that psychiatric disorder as a predictor of service use may be confounded by school performance and parental use of services, thus calling into question the extent to which program planning should be based on prevalence rates of child psychiatric disorder. Children from low-income families tend to make greater use of available services, suggesting that programs need to be tailored more specifically to their needs.

Evaluation of the Diagnostic Interview for Children and Adolescents for use in general population samples.

This article presents evaluative data on the use of the Diagnostic Interview for Children and Adolescents-Revised (DICA-R) to classify DSM-III-R disorders in the general population. Data for the analyses came from a probability sample (N = 251) of parent-child/adolescent dyads aged 6 to 16 separately administered the DICA-R on two occasions, 10- to 20 days apart, by trained lay interviewers and child psychiatrists. Data are presented on prevalence, test-retest reliability, parent-child/adolescent agreement, and trained lay interviewer-child psychiatrist agreement. High prevalences of oppositional defiant disorder derived from parent assessments and overanxious disorder and dysthymia derived from adolescent assessments suggest that these disorders may be overidentified. Interview data provided by 6- to 11-year olds to classify the internalizing disorders were too unreliable to be useful. Agreement between parent-child/adolescent dyads was generally low while agreement between trained lay interviewers-child psychiatrists was generally high.

Follow-up of psychiatric and educational morbidity among adopted children.

OBJECTIVE: The purpose of this study is to evaluate longitudinally the strength of association between adoptive status and psychiatric and educational morbidity and substance use. METHOD: This study makes use of data from the 1983 Ontario Child Health Study and 1987 follow-up. This community survey of children (4- to 16-years-old in 1983, 8- to 20-years-old in 1987) included a subpopulation of adopted children. The primary outcomes measured were psychiatric disorder, poor school performance, and substance use. RESULTS: Adoption, identified in 1983, in boys was a significant marker for psychiatric disorder in 1987. Adoption was not a significant risk indicator for educational morbidity or substance use in 1987. In the multivariate analyses, adoptive status demonstrated no independent influence on 1987 educational morbidity or substance use. However, adoptive status, in the presence of poor school performance in 1983, was a significant risk indicator for psychiatric disorder in 1987. CONCLUSIONS: Adopted children did not do significantly worse than nonadopted children over time in terms of educational morbidity or substance use, but adopted boys demonstrated a significantly increased risk of psychiatric disorder versus nonadopted boys.

Evaluation of the original Ontario Child Health Study scales.

This article presents evaluative information on the use of the original Ontario Child Health Study scales to serve as original-level measures of conduct disorder, hyperactivity and emotional disorder among children in the general (non clinic) population. Problem checklist assessments were obtained from parents and teachers of children aged six to 16 and youth aged 12 to 16 drawn from a general population (n = 1,751); and a mental health clinic sample (n = 1,027) in the same industrialized, urban setting. The results showed that the original OCHS scales possess adequate psychometric properties to be used as original-level measures of disorder. Correlations between individual items and their hypothesized scales were very strong, indicating convergent validity, while correlations between the same items and other (non hypothesized) scales were lower, indicating discriminant validity. Item analyses indicated that individual scale items possess both convergent and discriminant validity. Although the scales were skewed to the positive end of the continuum, they demonstrated good internal consistency (all estimates > or = 0.74) and test-retest (all estimates > or = 0.65) reliability. Finally, three different validity analyses confirmed hypotheses about how the original OCHS scales should perform if they provide useful measures of disorder.

Predicting substance use in early adolescence based on parent and teacher assessments of childhood psychiatric disorder: results from the Ontario Child Health Study follow-up.

This article examines relationships between psychiatric disorder, poor school performance, family dysfunction and low family income in a cohort of 8-12-year-olds and use of tobacco, marijuana and hard drugs 4 years later. Conduct disorder assessed by teachers predicted use of alcohol and hard drugs, while low family income and poor school performance predicted use of tobacco. Neither attention-deficit disorder nor emotional disorder was related to adolescent substance use. Although behavioural deviance in childhood is associated with adolescent substance use, it has limited potential for identifying groups at risk in the general population for purposes of preventing substance use in later years.

Correlates of children's use of physician and dentist services: Ontario Child Health Study follow-up.

OBJECTIVE: (1) To explore the correlates of dental and medical care utilization for children in Ontario and (2) to explore the stability of correlates of medical care use over time. METHOD: Data from the Follow-up Survey of the Ontario Child Health Study were used. Since likelihood of use of both dental and medical care clustered within households, one randomly chosen child per household, aged 8-16 years, contributed data to the analysis. Bivariate associations between use of services and descriptors of the child and his/her family were examined. RESULTS: Younger age, urban residents and parental perception of poorer health or hay fever/asthma increased the odds of a child receiving medical care in the previous six months. Dental care utilization was associated with younger age of child, higher education of mother and high family income. CONCLUSIONS: Across time, consistency was observed in the factors linked to children's use of medical services. Perceived need, the child's age and an urban location are related to greater probability of use.