C 2006) Journal of Psychopathology and Behavioral Assessment, Vol. 28, No. 1, March 2006 ( DOI: 10.1007/s10862-006-4538-x
DSM-IV Attention Deficit Hyperactivity Disorder Symptoms: Agreement Between Informants in Prevalence and Factor Structure at Different Ages Juan Antonio Amador-Campos,1,3 Maria Forns-Santacana,1 Joan Gu`ardia-Olmos,2 and Maribel Per´o-Cebollero2 Accepted February 5, 2005
The agreement between teachers’ and parents’ ratings of the prevalence of DSM-IV attention deficit hyperactivity disorder (ADHD) symptoms and the concordance of the factor structure of ADHD symptoms was analyzed in a sample of 653 Spanish schoolchildren aged 4 to 12 divided into two age groups. The prevalence of ADHD symptoms ranged between 0.66 and 16.73% and was higher when the rater was the teacher. Agreement between parents and teachers was low. Confirmatory factor analysis (CFA) shows a slightly better fit for the three-factor model (Inattention, Hyperactivity and Impulsivity) than for the two-factor model (Inattention and Hyperactivity–impulsivity), except for parents’ ratings in the sample of children under six. CFA using a multitrait–multimethod model (CFA-MTMM) shows similar results. KEY WORDS: Attention deficit hyperactivity disorder; DSM-IV symptoms; agreement between informants; confirmatory factor analysis.
The prevalence of attention deficit hyperactivity disorder (ADHD) in schoolchildren has been estimated to be between 3 to 6% (American Psychiatric Association [APA], 1994, 2000). Estimated prevalence rates vary for many reasons: the use of different criteria for diagnosis, the method or instrument of data collection (e.g., rating scales or interview), the sources of information (e.g., parents, teachers, or children, or combinations of the three), the symptom threshold, and sample characteristics (Amador, Forns, & Martorell, 2001; Gadow, Sprafkin, & Nolan, 2001; Gimpel & Kuhn, 2000; Gomez, Harvey, Quick, Scharer, & Harris, 1999; Nolan, Gadow, & Sprafkin, 2001; Pineda et al., 1999). Prevalences established from rating scales are often higher than those obtained using interviews and DSM-IV
diagnostic criteria. For example, Pineda et al., (1999) found a prevalence rate for ADHD of 18.2% in preschool children, 22.5% in children aged 6 to 11, and 7.3% in children aged 12 to 17, all rated by parents in the course of interviews. But when the DSM-IV diagnostic criteria are applied, the prevalence is approximately 5% (Baumgaertel, Wolraich, & Dietrich, 1995; Keenan & Wakschlag, 2000). In general, the prevalence rate for schoolchildren ranges between 5 and 10% (Scahill & SchwabStone, 2000; Verhulst, van der Ende, Ferdinand, & Kasius, 1997; Wolraich, Hannah, Baumgaertel, & Feurer, 1998). Diagnosis of ADHD requires that symptoms must be present in two or more settings—e.g., at school, or work, and at home (APA, 2000). This means that information must be gathered from different informants. Information from parents and teachers on ADHD symptoms is extremely useful in the assessment and diagnosis of ADHD (Barkley, 1998). However, a major problem is the low agreement between informants. Different sources may report large variations in the frequency and severity of symptoms and the information they provide may even be contradictory (Burns, Walsh, & Gomez, 2003; Crystal,
1 Departament
de Personalitat, Avaluaci´o i Tractament Psicol´ogics, Facultat de Psicologia, Universitat de Barcelona, Barcelona, Spain. 2 Departament de Metodologia de les Ci` encies del Comportament, Facultat de Psicologia, Universitat de Barcelona, Barcelona, Spain. 3 To whom correspondence should be addressed at Departament de Personalitat, Avaluaci´o i Tractament Psicol`ogics, Facultat de Psicologia, Universitat de Barcelona, Passeig de la Vall d’Hebron, 171. 08035, Barcelona, Spain; e-mail:
[email protected].
23 C 2006 Springer Science+Business Media, Inc. 0882-2689/06/0300-0023/0
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Amador-Campos, Forns-Santacana, Gu`ardia-Olmos, and Per´o-Cebollero
Ostrander, San Chen, & August, 2001; Fischer, Barkley, Fletcher, & Smallish, 1993; Wolraich et al., 2004). The degree of concordance is higher when the observers see the subject in the same context (that is, it is higher between the child’s father and mother or between the teacher and an observer in the classroom than between a parent and a teacher). The mean correlations vary between .24 for different contexts and .60 for the same context (Achenbach, McConaughy, & Howell, 1987; Clarke, Lewinsohn, Hops, & Seeley, 1992; Hinshaw, Han, Erhardt, & Huber, 1992). The agreement also varies according to the sample (clinically referred or community children) and to the measures used (ratings scales or interview, see Boyle et al., 1997; Crystal et al., 2001: Wolraich et al., 2004). Biederman, Faraone, Milberger, and Boyle (1993) found average correlations of .22 between parents’ and teachers’ ratings of ADHD symptoms assessed using questions derived from the Diagnostic Interview for Children and Adolescents, DICA (Reich & Welner, 1990). Mitsis, McKay, Schulz, Newcorn, and Halperin (2000) gathered information from parents and teachers of a group of 74 referred children using the structured interview Diagnostic Interview for Children, DISC (Shaffer, Fisher, Dulcan, & Davies, 1996). These authors found that the agreement between the ratings made by both types of informants was moderate and slightly higher for all the ADHD symptoms (r = .42) than for the hyperactivity– impulsivity symptoms (r = .39) or for the inattention symptoms alone (r = .30). The concordance between parents and teachers regarding the diagnosis of any subtype of ADHD was modest (kappa = .20), and the percentage of agreement with respect to the type of disorder was low: 3.9% for the combined type (ADHD-C), 3.6% for the predominantly inattentive type (ADHD-I), and 1.8% for the predominantly hyperactive–impulsive type (ADHD-HI). Antrop, Roeyers, Oosterlaan, and Van Oost (2002) analyzed the concordance between the information provided by teachers and parents in a group of children with diagnoses of ADHD and found correlations of .13 for inattention symptoms and .09 for hyperactivity– impulsivity symptoms. The degree of agreement between parents and teachers regarding the presence or absence of this disorder was low: Cohen’s kappa was .04 for ADHD-I, and k = −.08 for ADHD-HI; the percentage of agreement was 7.4% in both cases. Wolraich et al. (2004) found low agreement between parent and teacher reports of ADHD symptoms in a sample of 243 children in elementary school (grades K-4) who were at risk for ADHD. Parent and teacher agreement on a DSM-IV based questionnaire was low: Inattentive (r = .34, k = .27), Hyperactive/impulsive (r = .27, k = .22), and Combined
(r = .31, k = .07). In general, the agreement between parents’ and teachers’ ratings of ADHD symptoms is moderate, being higher for clinically referred children than for community children. As regards the diagnosis of subtypes of the condition, the agreement between parents and teachers is low. Several studies point out that the symptoms of ADHD change during the developmental process. In community populations, parents and teachers consider that the youngest children (preschoolers) show more hyperactivity and impulsivity than inattention (Amador et al., 2001; Barkley, Fischer, Edelbrock, & Smallish, 1990; Brito, Pinto, & Lins, 1995; DuPaul et al., 1997; DuPaul et al., 1998; Gomez et al., 1999; Rohde et al., 2001; Pineda et al., 1999). Inattention, overactivity and impulsivity behaviors are common in many preschoolers. Some of these behaviors are frequent and intensive enough to worry parents and teachers, but they tend to be temporary and recede with time. In the cases where these behaviors are frequent and intense enough to warrant ADHD diagnosis, the condition persists during childhood or adolescence in only 48% of cases (Barkley, 1998). If the frequency of ADHD manifestations or dimensions varies according to age, it would be fruitful to analyze the concordance between the ratings of ADHD symptoms made by teachers and parents of preschool and school age children. Several recent studies have used Confirmatory Factor Analysis (CFA) to analyze the factor structure of the ratings of the DSM-IV-ADHD symptoms provided by parents and teachers (Amador, Forns, Martorell, Gu`ardia, & Per´o, 2004; Beisser, Dion, & Gotowiec, 2000; Burns, Boe, Walsh, Sommers-Flanagan, & Teegarden, 2001; Collet, Crowley, Gimpel, & Greenson, 2000; DuPaul et al., 1997; DuPaul et al., 1998; Gomez et al., 1999; Gomez, Burns, Walsh, & Alves de Moura, 2003; Molina, Smith, & Pelham, 2001; Rohde et al., 2001, and Wolraich et al., 2003). These studies showed that the two-factor model of ADHD symptoms (Inattention and Hyperactivity– impulsivity) provided a good fit; however, other authors have found that the three-factor model (Inattention, Hyperactivity and Impulsivity) provided a slightly better fit than the two-factor model (eg. Gomez et al., 1999). Gomez et al. (2003), and Burns et al. (2003) used a multitrait–multisource design to analyze the construct validity of parents’ and teachers’ ratings of ADHD symptoms and the amount of trait, source, and error variance. They found that trait and source accounted for almost all the variance in parents’ and teachers’ ratings and that source variance was equal to or much stronger than trait effects for symptom clustering, concluding that “teachers are better able to detect the hyperactive/impulsive trait than parents and that parents are better able to detect the
DSM-IV Attention Deficit Hyperactivity Disorder Symptoms inattention trait than the teachers” (Burns et al., 2003, p. 538). The aim of this study is to analyze: (1) the agreement between teachers and parents in the prevalence of Inattention, Hyperactivity–impulsivity and total ADHD symptoms; (2) the factor structure of DSM-IV-ADHD symptoms for two different age groups of Spanish children: preschoolers (4 and 5 years), and school age children (over 6 years of age).
METHOD Participants The sample comprised 653 preschool and schoolchildren (375 girls, 57.4%, and 278 boys, 42.6%), rated by teachers and parents, randomly selected from 48 classrooms in six partially State-funded schools in the city of Barcelona (Spain). The age range was from 4 to 12 years old—48 to 144 months—(M = 98.46; SD = 27.62 months; M = 98.57; SD = 28.11 months, for boys and girls, respectively). The sample was divided into two groups according to age: 151 children younger than 6 (between 48 and 71 months) and 502 older than 6 (between 72 and 144 months). The socioeconomic status of the sample was in the medium range according to the Hollingshead index (1975). Questionnaires were initially sent to the parents and teachers of 1200 children, of which 1018 were returned, representing an overall response rate of 84.83%. Of the questionnaires returned, 896 (88.02%) were completed by teachers and 775 (76.13%) by parents. Of the parents’ ratings, 51.2% were completed by the child’s mother, 18.3% by the father, and 30.5% by both parents. Both teachers and parents completed the questionnaires in 653 cases (64.15%).
Measure A bilingual Spanish–Catalan questionnaire was prepared consisting of 18 items from the ADHD symptom list published in DSM-IV (APA, 1994). The items were worded in the same way as the description of the symptoms in the DSM-IV, except for the omission of the term “often.” The first nine items included inattention symptoms and the other nine referred to hyperactivity and impulsivity. For each item, parents and teachers selected the answer that best described the frequency of the behavior being rated. The frequency of each type of behavior or symptom was scored on a four-point Likert scale ranging
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from 0 (Not true at all, never, seldom) to 3 (Very much true, very often, very frequent). The items rated 2 or 3 were taken to indicate presence of the symptom. To calculate the number of Inattention (ADHD-I) and Hyperactivity–impulsivity (ADHDHI) symptoms, the number of items rated 2 or 3 was added in each of these dimensions. The highest score for ADHD-I or ADHD-HI was thus 9 and the lowest 0. For the total symptoms of ADHD (ADHD-C), the maximum total score was 18 and the minimum 0. Children with scores of six or over on ADHD-I or ADHD-HI were assigned to the ADHD-I group or the ADHD-HI group respectively; children with six or more symptoms on both ADHD-I and ADHD-HI were included in the ADHD-C group. Procedure Parents and teachers received the questionnaire in a closed envelope, with a letter requesting their voluntary and unpaid collaboration in a developmental study of certain behaviors in their children/pupils. The informants were not told explicitly that the questionnaire referred to problems of inattention, hyperactivity and impulsivity. Parents and teachers were asked to evaluate the items according to the habitual behavior of their children or pupils over the last six months. To ensure that teachers were sufficiently familiar with their students, data collection was scheduled for the second semester. Data Analysis Prevalence The prevalence of Inattention symptoms (ADHDI), Hyperactivity–impulsivity symptoms (ADHD-HI), and Total ADHD symptoms (ADHD-C) was studied separately for parents and teachers. McNemar’s χ 2 and Cohen’s kappa coefficients were computed to assess interinformant agreement. This analysis was performed with the sample as a whole and with the two age groups in which the sample was divided (
