Screening for lead poisoning by fingerstick in suburban pediatric practices

OBJECTIVE

To assess the false-positive rate of blood lead determinations on samples obtained by fingerstick from children screened in private suburban and rural practices.

METHODS

Screening capillary lead samples were obtained by fingerstick; children with capillary lead levels of 0.7 mumol/L (15 micrograms/dL) or greater were recalled for a confirmatory venous lead test that served as the criterion standard. Parents completed a five-question risk assessment questionnaire at the time of initial screening.

SETTING

Four private suburban to rural practices that serve predominantly white, middle-class populations.

PARTICIPANTS

Children seen for routine care between August 1992 and February 1993 (N = 1085; 98% between 6 months and 6 years of age).

RESULTS

Capillary lead level was 0.7 mumol/L (15 micrograms/dL) or greater in 35 children (3% of total sample); venous lead samples were obtained in 30 patients. Nine of the elevated capillary lead results were true-positives (venous lead = 0.7, 0.8, 0.8, 0.9, 0.9, 0.9, 1.1, 1.1, and 1.7 mumol/L [15, 17, 17, 18, 18, 18, 22, 22, and 35 micrograms/dL]); parents of only two of these children answered yes to any question on the risk assessment questionnaire. Although the false-positive rate of the capillary lead screening test was 70% (21/30) in this setting, only 2% of the total sample had a false-positive screening test (an average of fewer than one false-positive per month per practice). Screening by fingerstick allowed phlebotomy to be avoided for 97% of the children.

CONCLUSION

Fingerstick screening for lead poisoning is a reasonable alternative to direct venous testing within private suburban and rural practices, provided that care is taken to avoid specimen contamination, that appropriate caution is used in the interpretation of screening test results, and that medical and environmental interventions are based on the results of confirmatory venous testing.

The accuracy of children's reports with anatomically correct dolls

The accuracy of children's reports of alleged sexual abuse during interviews with anatomically correct dolls is the focus of considerable controversy. This study used an analog experience to measure empirically the accuracy of reports in a relevant, but controlled setting: the forensic medical examination for suspected sexual abuse. Twenty-one 3- to 7-year-old children were interviewed about what occurred during previous examinations with open-ended questions, open-ended questions with anatomically correct dolls, and direct questions with the dolls. Children provided significantly more accurate reports and fewer omissions with direct questions using the dolls compared with either of the two open-ended sections, but there was no significant difference in the number of false reports across the three sections of the interview. These results suggest that anatomically correct dolls may bolster the recall of children's memory in the setting of direct questions without prompting false reports.

A randomized, controlled trial of a school-based, multi-faceted AIDS education program in the elementary grades: the impact on comprehension, knowledge and fears

OBJECTIVE

Several educational theorists have suggested that young children are unlikely to benefit from detailed instruction regarding AIDS prevention because of inherent developmental cognitive limitations. This study aims to determine whether AIDS education in the elementary grades can advance young children's understanding of this illness.

METHODS

A randomized, controlled trial was used to measure the impact of a 3-week, multifaceted AIDS education program on conceptual understanding, factual knowledge, and fears about AIDS in 189 students in grades kindergarten through 6th. The ASK (AIDS Survey for Kids), a standardized, semistructured interview that measures conceptual understanding, factual information, and fears about AIDS, was administered before and after the intervention.

RESULTS

Children in the intervention group, as compared to those in the control group, showed significant (P < .0001) gains in their level of understanding of the concepts of causality and prevention of AIDS. These results were unaffected by controlling for grade, gender, race, socioeconomic status, and verbal fluency. The gains in children's understanding of causality of AIDS represented at least 2 years' growth in the level of conceptual sophistication and persisted at a follow-up evaluation several months later. After the intervention, more children (P < .001) in the intervention group than in the control group accurately identified causes of AIDS in response to open-ended questions: germ/germ theory (41% vs 13%), mother-to-infant transmission (54% vs 15%), blood transmission (83% vs 40%), and sexual transmission (56% vs 30%). Fewer than half as many children in the intervention group responded incorrectly to each of five direct questions about transmission of HIV through casual contact. The intervention did not increase children's fears about the illness.

CONCLUSIONS

A short, developmentally based, multifaceted AIDS education program in the elementary grades can advance children's conceptual understanding and factual knowledge about AIDS and decrease their misconceptions about casual contact as a means of acquiring the illness, without increasing their fears. Significant advances in conceptual understanding about AIDS can be achieved through direct educational interventions.

Field trial for autistic disorder in DSM-IV

OBJECTIVE

This project focused on the development of the definition of autism for DSM-IV.

METHOD

Multiple sites were involved in obtaining information regarding 977 patients with the following clinician-assigned diagnoses: autism (N = 454), other pervasive developmental disorders (N = 240), and other disorders (N = 283). A standard coding system was used, and the raters (N = 125) had a range of experience in the diagnosis of autism. Patterns of agreement among existing diagnostic systems were examined, as was the rationale for inclusion of other disorders within the class of pervasive developmental disorders.

RESULTS

The DSM-III-R definition of autism was found to be overly broad. The proposed ICD-10 definition most closely approximated the clinicians' diagnoses. Inclusion of other disorders within pervasive developmental disorders appeared justified. Partly on the basis of these data, modifications in the ICD-10 definition were made; this and the DSM-IV definition are conceptually identical.

CONCLUSIONS

The resulting convergence of the DSM-IV and ICD-10 systems should facilitate both research and clinical service.

Screening for lead poisoning in an urban pediatric clinic using samples obtained by fingerstick

OBJECTIVE

To assess the false positive rate of blood lead (BPb) determinations on samples obtained by fingerstick from children screened in an urban clinic.

METHOD

From a single fingerstick (N = 1573), blood was collected in a capillary tube for determining lead concentration (CPb) by graphite furnace and an additional sample was absorbed onto a filter paper for determining lead concentration (FPb) by atomic absorption spectrophotometry with Delves cup. Zinc protoporphyrin (ZPP) was measured immediately and a confirmatory venous lead (VPb) specimen was obtained at the same visit if the ZPP was > or = 35 micrograms/dL (0.6 mumol/L); children with either a CPb or FPb > or = 15 micrograms/dL (0.7 mumol/L) were later recalled for determining VPb.

RESULTS

For the 172 children who had a VPb on the same day as the screening tests, the false positive rates (95% confidence intervals) at a lead threshold of 15 micrograms/dL (0.7 mumol/L) were: CPb, 13.5% (6.7-20.3); FPb, 19.1% (11.8-26.4). Analyses using all 679 screens with a paired venous specimen (mean delay between screen and venous testing = 30 days) yielded much higher false positive rates (CPb, 31.3%; FPb, 46.0%).

CONCLUSIONS

Screening for lead poisoning is feasible within an urban pediatric clinic by direct measurement of lead concentration in blood samples obtained by fingerstick. The false positive rate that can be obtained is acceptable given the precision of measuring BPb concentration. Practitioners using a staged screening protocol may incorrectly attribute a higher false positive rate to the screening tests, when much of the error may be due to the temporal variability of BPb resulting from both biologic variability in BPb concentration and intermittent exposures.

Re-examining threats to the reliability and validity of putative brain-behavior relationships: new guidelines for assessing the effect of patients lost to follow-up

It often happens in behavioral and biomedical research that subjects in prospective, multiple assessment investigations, including clinical trials, are lost to follow-up evaluations. The purpose of this report is to outline a model that will enable the investigators to determine the extent to which results based upon the maintained cohort can be generalized to the attrited cohort, or those subjects lost to follow-up. While our proposed model derives from a specific application pertaining to changes in personality and affect behaviors following left and right hemisphere stroke, it should apply, with appropriate study-specific modifications, to a wide range of follow-up research designs in neuropsychology, behavioral science more generally, and other areas of biomedical research.

Multiple comparison methods: establishing guidelines for their valid application in neuropsychological research

This comment serves to provide a rationale for research clinical neuropsychologists to decide: (1) under what conditions multiple comparison methods are required; and (2) what specific guidelines can be used to distinguish conditions favoring a given multiple comparison technique over its competitors. The topic is discussed both for the parametric and nonparametric case, as well as for post hoc tests following both statistically significant main effects and interactions.

Understanding of acquired immunodeficiency syndrome by elementary school children--a developmental survey

OBJECTIVES

The developmental process by which young children acquire an understanding of the concepts of causality, treatment, and prevention of illness as related to acquired immunodeficiency syndrome (AIDS) is poorly understood. Previous studies have focused on adolescent populations and have measured the facts that children seem to know rather than their understanding of relevant concepts. Such approaches are likely to overestimate the child's true level of understanding and obscure significant misconceptions. The aims of this project are to measure directly the level of understanding of the concepts of causality, treatment, and prevention of AIDS in healthy, elementary school children and to assess the sociodemographic variables associated with their conceptual understanding.

METHODS

Using a new, developmentally based, semistructured interview protocol (ASK, AIDS Survey for Kids), 361 children (57% black, 24% Hispanic, 19% white) in kindergarten through sixth grade at four public schools in New Haven, CT were interviewed. Responses to questions about causality, treatment, and prevention were scored for each of three illnesses (AIDS, and for comparison, colds and cancer) based on the level of conceptual sophistication of the response, irrespective of its factual accuracy.

RESULTS

Scores for each of the concepts were highly intercorrelated and were correlated most strongly with grade level (R = .31 to .50, P < .0001 for each of these correlations, with the exception of the treatment of AIDS). Gender, race, and socioeconomic status did not contribute significantly to the variance observed for any of the concept scores in a linear regression model. Over-all, children's level of understanding of causality was significantly less sophisticated for AIDS than for colds (P < .0001); their level of conceptual understanding for the causality of AIDS was not significantly different from that of cancer (P = .9).

CONCLUSIONS

Children's understanding of causality, treatment, and prevention of AIDS, as measured by the ASK, follows the same developmental sequence reported for children's understanding of general physical illness. Sociodemographic variables, such as race, gender, and socioeconomic status do not affect children's level of sophistication of these developmental concepts. These results have implications for the creation of developmentally appropriate and effective AIDS education curricula for primary and elementary grades. They also offer guidance to health care providers in their efforts to educate parents and young children about this important topic.

Quantifying social development in autism

OBJECTIVE

This study was concerned with the development of quantitative measures of social development in autism.

METHOD

Multiple regression equations predicting social, communicative, and daily living skills on the Vineland Adaptive Behavior Scales were derived from a large, normative sample and applied to groups of autistic and nonautistic, developmentally disordered children. Predictive models included either mental or chronological age and other relevant variables.

RESULTS

Social skills in the autistic group were more than two standard deviations below those predicted by their mental age; an index derived from the ratio of actual to predicted social skills correctly classified 94% of the autistic and 92% of the nonautistic, developmentally disordered cases.

CONCLUSIONS

The findings are consistent with the idea that social disturbance is central in the definition of autism. The approach used in this study has potential advantages for providing more precise measures of social development in autism.

Three diagnostic systems for autism: DSM-III, DSM-III-R, and ICD-10

ICD-10 draft research criteria for childhood autism were applied to a previously published data set comparing DSM-III and DSM-III-R to clinicians' diagnoses of autism. The ICD-10 approach paralleled clinicians' patterns of diagnosis and, to a lesser extent, the DSM-III system. Relative to either clinicians, DSM-III, or ICD-10 the DSM-III-R system overdiagnosed the presence of autism. Implications for research and for future revision of diagnostic criteria are discussed.

Assessing the reliability of clinical scales when the data have both nominal and ordinal features: proposed guidelines for neuropsychological assessments

The purpose of this article is to present, for the first time, a comprehensive methodology for assessing the reliability of a clinical scale that is frequently utilized in neuropsychological research and in biomedical studies, more generally. The dichotomous-ordinal scale is characterized by a single category of "absence" and two or more ordinalized categories of "presence" of a symptom trait, state, or behavior, and it also has special properties that need to be understood in order for its reliability to be appropriately assessed. Using the Brief Psychiatric Rating Scale (BPRS) as a clinical example, we cover the principles of expressing scale reliability in terms of a dichotomy ("absence" - "presence" of a given BPRS symptom); as a trichotomy ("none"; "mild to moderate" symptomatology; and "severe" symptomatology); and as the full 7-category dichotomous-ordinal scale: "none," "very mild," "mild," "moderate," "moderately severe," "severe," and "extremely severe." Criteria are presented that can be used to evaluate which of these three formats produces the most reliable results. Finally, we address, with a second sample, the important issue of replication, or whether the original reliability findings generalize to other independent populations.

The outpatient treatment of depression. Implications of outcome research for clinical practice

Multiple studies have demonstrated that individual psychotherapy, pharmacotherapy, and the two in combination are all effective treatments for depressed outpatients. However, the implications of these data for clinical practice have been incompletely considered, and the often drawn mistaken conclusion is that they support routine treatment with psychotherapy and pharmacotherapy together. Analyses of treatment success rates, treatment failure rates, and treatment dropout rates indicate that combined treatment offers no advantage over treatment with psychotherapy alone and only modest advantage over treatment with pharmacotherapy alone. Routine use of combined treatment, therefore, exposes patients to unnecessary costs and side effects. The data suggest that psychotherapy alone should usually be the initial treatment.

Demographic, clinical, and psychosocial predictors of the reliability of mothers' clinical judgments

The purpose of this study was to investigate to what extent selected adverse demographic, clinical, and psychosocial data measured at the 2-week well child visit could predict poorer reliability of mothers' judgments during acute illness episodes over the next 32 months. The study was a randomized trial of the Acute Illness Observation Scales (AIOS); 369 mothers participated, 183 in the intervention group using the Acute Illness Observation Scales and 186 in the control group using a three-point global assessment scale. There were 704 acute illnesses judged simultaneously and independently by mothers and pediatricians. Standard Pearson r correlations were performed between the independent variables, taken singly and in all possible combinations, and the dependent variable, reliability of mothers' judgments as measured by weighted kappa (kappa W). Group assignment was entered as an independent variable. Analyses were performed separately for all first, second, and third acute illness visits to control for any "practice effect" (analysis 1). To control for consistency of observers, the first, second, and third visits of mothers with three visits were also analyzed (analysis 2). Depending on the visit number, adverse demographic, clinical, and psychosocial characteristics did correlate with poorer reliability independent of group assignment. The correlations ranged from small (analysis 1, first visit, multiple variable r2 = 4%) to large (analysis 2, second visit, multiple variable r2 = 29%). Controlling for both visit number and consistency of observers vs visit number alone (analysis 2 vs analysis 1) increased multivariate correlations to kappa W. The results support the untoward impact that adverse demographic, clinical, and psychosocial factors have on mothers' clinical judgment. These data may assist pediatricians in identifying parents who might benefit from more intensive teaching and support about acute illness episodes in their children.

Establishing the reliability and validity of neuropsychological disorders with low base rates: some recommended guidelines

The issues of low prevalence in the context of the diagnosis of neuropsychological disorders in the larger community is discussed. Guidelines are proposed for producing reliability and validity estimates which are clinically, as well as statistically meaningful.

Observer variability in echo-Doppler measurements of portal flow in cirrhotic patients and normal volunteers

The intraobserver and interobserver variability in measuring the portal vein flow by the echo-Doppler technique was evaluated in a blind controlled study. A total of 22 cirrhotic patients and 14 normal volunteers were examined by two skilled operators using duplex Doppler within a period of 1-3 mo (6 cirrhotics and 7 normal volunteers by both observers). Area, mean velocity, and flow were measured (4 measurements: A, B on day 1; C, D on day 2). The intraclass correlation coefficient was used to assess both the statistical and clinical significance of intraobserver and interobserver agreement for the measurements of these three parameters. The level of intraobserver agreement for each parameter on normal subjects and cirrhotics was obtained from the two measurements on the same day and from the two measurements at the same time on consecutive days. Overall agreement between the four measurements was also calculated. Levels of interobserver agreement were obtained by calculating separately the intraclass correlation coefficient from each of the four pairs by measurements made on the same subject by the two observers over the same period of 2 days. The coefficient of variation was also used to compare the variability in these measurements. Overall, intraobserver agreement on normal subjects varied from good to excellent for observer 1, and from fair to good for observer 2. On cirrhotic patients, observer 1 was excellent at all times for all parameters. Observer 2 had lower intraclass correlation coefficient values, especially for velocity on consecutive days. For the best of the two observers on the portal flow, the coefficient of variation in cirrhotic patients ranged from 2%-30% with a mean +/- SEM of 12% +/- 4%. No acceptable interobserver agreement was found between the two observers in either of the two samples of subjects. These results support the use of this technique mainly for the determination of rapid and large changes in portal hemodynamics within a short period of time. The technique seems to have low precision in monitoring chronic changes in portal hemodynamics.

Mothers' clinical judgment: a randomized trial of the Acute Illness Observation Scales

The purpose of this study was to investigate whether the reliability, sensitivity, and specificity of mothers' judgments about acute illnesses in their children could be improved by using the Acute Illness Observation Scales (AIOS). At the 2-week well child care visit in a primary care center and a private practice, 369 mothers were divided at random into an intervention group (n = 183) and a control group (n = 186). A teaching film and booklet were used to educate mothers in the intervention group about the AIOS; control group mothers were taught a 3-point global scoring system for evaluating the chance of serious illness. In the 32 months of follow-up, 704 acute illnesses were evaluated in tandem and independently by mothers and pediatricians before the history and physical examination; 20 of these illnesses were serious. The judgments of the intervention group were more reliable than those of the control group (weighted kappa = 0.50 vs 0.26, respectively), as was the specificity of their judgments (85% vs 52%, respectively; p less than 0.0001). No difference was noted in the sensitivity of intervention group and control group mothers' judgments (80% vs 90%, respectively). Teaching parents to assess specific clinical information, as represented in the AIOS, has its greatest effect on the reliability and specificity, not the sensitivity, of their judgments. Such teaching could lead to fewer unnecessary office visits during acute illnesses.

High agreement but low kappa: I. The problems of two paradoxes

In a fourfold table showing binary agreement of two observers, the observed proportion of agreement, p0, can be paradoxically altered by the chance-corrected ratio that creates kappa as an index of concordance. In one paradox, a high value of p0 can be drastically lowered by a substantial imbalance in the table's marginal totals either vertically or horizontally. In the second pardox, kappa will be higher with an asymmetrical rather than symmetrical imbalanced in marginal totals, and with imperfect rather than perfect symmetry in the imbalance. An adjustment that substitutes kappa max for kappa does not repair either problem, and seems to make the second one worse.

The Structured Clinical Interview for DSM-III-R Dissociative Disorders: preliminary report on a new diagnostic instrument

The authors describe the Structured Clinical Interview for DSM-III-R Dissociative Disorders (SCID-D), which investigates five groups of dissociative symptoms (amnesia, depersonalization, derealization, identity confusion, and identity alteration) and systematically rates both the severity of individual symptoms and the evaluation of overall diagnosis of dissociative disorder. Preliminary findings from a study of 48 subjects with and without psychiatric diagnoses indicate good to excellent reliability and discriminant validity for the SCID-D as a diagnostic instrument for the five dissociative disorders and as a tool for the evaluation of dissociative symptoms encountered within nondissociative syndromes.

High agreement but low kappa: II. Resolving the paradoxes

An omnibus index offers a single summary expression for a fourfold table of binary concordance among two observers. Among the available other omnibus indexes, none offers a satisfactory solution for the paradoxes that occur with p0 and kappa. The problem can be avoided only by using ppos and pneg as two separate indexes of proportionate agreement in the observers' positive and negative decisions. These two indexes, which are analogous to sensitivity and specificity for concordance in a diagnostic marker test, create the paradoxes formed when the chance correction in kappa is calculated as a product of the increment in the two indexes and the increment in marginal totals. If only a single omnibus index is used to compared different performances in observer variability, the paradoxes of kappa are desirable since they appropriately "penalize" inequalities in ppos and pneg. For better understanding of results and for planning improvements in the observers' performance, however, the omnibus value of kappa should always be accompanied by separate individual values of ppos and pneg.

Blood cultures in private pediatric practice: an eleven-year experience

We describe an 11-year experience with bacteremia in a two-physician suburban private pediatric practice. Patients studied were ages 3 to 24 months with a body temperature of greater than or equal to 39.4 degrees C and nonfocal illness. During these 11 years, 23 such babies had bacteremia, 21 with Streptococcus pneumoniae. Three risk factors for bacteremia were identified: absolute neutrophil counts greater than or equal to 10,500/microliters; cool season (November to April), and Yale observation score greater than 10. The positive predictive values for bacteremia were 33, 41 and 57%, respectively, when (1) absolute neutrophil count was greater than or equal to 10,500, (2) absolute neutrophil count was greater than or equal to 10,500 and it was the cool season, and (3) all 3 risk factors existed. Of 158 babies at low risk for bacteremia by these criteria, none was treated and none developed serious complications of bacteremia. Eight of the 23 bacteremic infants received no expectant antibiotic therapy and 15 received presumptive amoxicillin treatment in dosages ranging from 20 to 174 mg/kg/day. Twelve bacteremic infants either were not treated or received dosages of 100 mg/kg/day or less; complications developed in 5 of the 12 (persistent bacteremia, 2; facial cellulitis, 3). The remaining 11 bacteremic babies received approximately 150 mg/kg/day (range, 136 to 174) and none had complications (P = 0.03 by Fisher's exact test). The costs of identifying and treating infants suspected of having possible occult bacteremia were examined.

DSM-III and DSM-III-R diagnoses of autism

The authors examined the reliability, sensitivity, and specificity of DSM-III and DSM-III-R criteria for autism in relation to each other and to clinical diagnoses in 114 children and adults (52 diagnosed by clinicians' best judgment as autistic and 62 as nonautistic but developmentally disordered). They used a standard, structured coding scheme to evaluate each patient. The reliability of specific criteria was generally high. Although DSM-III criteria were highly specific, they were less sensitive; the reverse was true for DSM-III-R. The authors conclude that the diagnostic concept of autism in DSM-III-R appears to have been substantially broadened.