Psychometric properties of the Spence Children’s Anxiety Scale with young adolescents

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Abstract

The psychometric properties of the Spence Children’s Anxiety Scale (SCAS) were examined with 875 adolescents aged 13 and 14 years. This self-report measure was designed to evaluate symptoms relating to separation anxiety, social phobia, obsessive-compulsive disorder, panic-agoraphobia, generalized anxiety, and fears of physical injury. Results of confirmatory and exploratory factor analyses supported six factors consistent with the hypothesized subtypes of anxiety. There was support also for a model in which the first-order factors loaded significantly on a single second-order factor of anxiety in general. The internal consistency of the total score and sub-scales was high, and 12-week test–retest reliability was satisfactory. The SCAS correlated strongly with a frequently used child self-report measure of anxiety and significantly, albeit at a lower level, with a measure of depression.

Introduction

Anxiety disorders are a relatively common problem among adolescents. Studies suggest a point prevalence of around 5–10%, and lifetime prevalence around 20%, with estimates varying according to the population, measure, and level of impairment used to determine presence of a disorder (Essau, Conradt, & Petermann, 2000; Fergusson, Horwood, & Lynskey, 1993; Lewinsohn et al., 1993; Shaffer, Fisher, Dulcan, & Davies, 1996). Researchers and clinicians have become increasingly aware of the significance of anxiety disorders in adolescence, in terms of adverse social and educational outcomes and risk of persistence through to adulthood (Spence, 2001). This has been accompanied by a recent increase in research into the treatment and prevention of adolescent anxiety. However, research into development of reliable and valid methods for assessment of anxiety in adolescents has lagged behind.

Self-report represents an important method of assessing adolescent anxiety, given that many aspects of anxiety represent subjective cognitive and emotional experiences that are not open to observation by others. To date, the content of most self-report anxiety measures has focused on the general aspects of trait or state anxiety or specific fears. Commonly used measures include the Revised Children’s Manifest Anxiety Scale (RCMAS; Reynolds & Richmond, 1978), the State-Trait Anxiety Inventory for Children (Spielberger, 1973) and the Fear Survey Schedule for Children—Revised (Ollendick, 1983). While providing valuable information relating to general aspects of anxiety or fears, these measures do not produce data relating to occurrence or severity of anxiety symptoms relevant to specific anxiety disorder categories as described in diagnostic classification systems such as DSM-IV (American Psychiatric Association, 1994). Furthermore, traditional child and adolescent self-report measures of anxiety represent downward extensions of adult anxiety scales, and include items that may be of less relevance to anxiety in younger populations.

Recently, clinical researchers have sought to develop symptom specific instruments that correspond to DSM-IV anxiety disorder categories and that include items developed for child and adolescent populations. Such measures include the Multidimensional Anxiety Scale for Children (March et al., 1997; March, Sullivan, & Parker, 1999), the Screen for Child Anxiety Related Emotional Disorders (Birmaher et al., 1997) and its revision (Muris, Merckelbach, Schmidt, & Mayer, 1999) and the Spence Children’s Anxiety Scale (Spence, 1998). The psychometric properties of these measures have been shown to be good, with empirical support for test–retest reliability and internal consistency (Muris, Gadet, Moulaert, & Merckelbach, 1998; Muris, Merckelbach, van Brakel, Mayer, & van Dongen, 1998; Muris et al., 1999; Muris, Schmidt, & Merckelbach, 2000).

The present study focuses on the psychometric properties of the Spence Children’s Anxiety Scale with young adolescents. The SCAS assesses the young person’s perception of the frequency with which they experience symptoms relating to obsessive-compulsive disorder, separation anxiety, social phobia, panic/agoraphobia, generalized anxiety/overanxious disorder and fears of physical injury. The original paper describing development of the SCAS involved a large sample of Australian children aged 8–12 years (Spence, 1998). Spence (1998) demonstrated high internal consistency for the total score and factor scores, acceptable 6-month test–retest reliability, and high concurrent validity with the RCMAS. SCAS scores also differed significantly between clinically diagnosed anxious versus non-anxious children, with sub-scale scores reflecting the type of presenting anxiety disorder in the clinical sample. Results of the confirmatory and exploratory factor analyses were supportive of the DSM-IV constructs of anxiety disorders, but with first-order factors loading strongly on a higher-order factor of anxiety in general. Muris et al. (2000) also found evidence to support the strong psychometric properties of the SCAS with Dutch 7–19-year-olds. This study, although supporting reliability and concurrent validity of the SCAS with adolescents, did not examine the factor structure of the SCAS with an adolescent sample specifically. Results showed that the hypothesized six, correlated factor model provided a good fit of the SCAS data with 7–19-year-olds. In contrast, no satisfactory model was found for the SCARED when all its sub-scales were included in the confirmatory factor analysis. However, the sample used in the Muris et al. (2000) study ranged from 7 to 19 years and confirmatory factor analysis was not conducted for separate age groups. Also, their study did not examine the possibility of a higher-order factor of anxiety for the SCAS.

The present study extends previous research by examining the factor structure of the SCAS with a large sample of 13- and 14-year-old adolescents. It was hypothesized that data would be best explained by a six, correlated factor model in which questionnaire items loaded upon factors relating to social phobia, separation anxiety, obsessive-compulsive problems, panic/agoraphobia, fears of physical injury and generalized anxiety disorder, broadly consistent with DSM-IV anxiety disorders. Four models were compared, namely: (i) a single factor, (ii) six, uncorrelated factors, (iii) six, correlated factors, and (iv) six factors, loading onto a single second-order factor. It was predicted that the six factors would be strongly intercorrelated, given evidence of high levels of comorbidity between child anxiety disorders (Anderson & McGee, 1994). Further, in line with results of Spence, 1997, Spence, 1998, it was predicted that this high degree of intercorrelation between factors would be explained by a single, higher-order factor of anxiety in general. The study also examined the internal consistency, 12-week test–retest reliability and convergent and divergent validity of the SCAS in terms of association with measures of child anxiety and depression.

Section snippets

Participants

All participants (N=875) were aged 13 or 14 years (mean age 13.51 years, S.D.=.51 years) living in the metropolitan area of Brisbane, Australia. The sample included 472 males (54%) and 403 females (46%). Participants were drawn from six co-educational, independent, private schools within the Brisbane area, and schools were selected to represent varying levels of socio-economic advantage and religious affiliation. Students were predominantly from Anglo-Saxon families, with English as their

Confirmatory factor analysis

Confirmatory factor analysis was conducted to determine whether the factor structure of the measure did indeed reflect the six dimensions of anxiety disorder that the SCAS purported to evaluate. The data were examined using EQS (Bentler, 1995) with elliptical reestimated least squares (ERLS) estimation using the correlation matrix. ERLS estimation was selected given that tests of normality revealed evidence of significant positive skewness and kurtosis among many of the questionnaire items.

Discussion

The present study examined psychometric properties of the SCAS with a young adolescent population. In keeping with the findings for children, confirmatory factor analysis with the young adolescent age group demonstrated that a model with six correlated factors provided a good fit of the data. Strong support was found for a six-correlated factor model involving six factors related to panic/agoraphobia, social phobia, separation anxiety, obsessive-compulsive problems, generalized anxiety and

References (39)

  • T.H. Ollendick

    Reliability and validity of the Revised Fear Survey Schedule for Children (FSSC-R)

    Behavior Research and Therapy

    (1983)
  • H. Orvaschel et al.

    Children and depression: the children of depressed parents; the childhood of depressed patients; depression in children

    Journal of Affective Disorders

    (1980)
  • D. Shaffer et al.

    The NIMH Diagnostic Interview Schedule for Children Version 2.3 (DISC-2.3): description, acceptability, prevalence rates, and performance in the MECA study

    Journal of the American Academy of Child and Adolescent Psychiatry

    (1996)
  • S.H. Spence

    A measure of anxiety symptoms among children

    Behavior Research and Therapy

    (1998)
  • Achenbach, T. M. (1991). Manual for the Child Behavior Checklist/4–18 and 1991 Profile. Burlington, VT: University of...
  • American Psychiatric Association. (1994). Diagnostic and Statistical Manual of Mental Disorders (4th ed.). Washington,...
  • Anderson, J. C. (1994). Epidemiological issues. In: T. H. Ollendick, N. J. King, et al. (Eds.), International handbook...
  • J.C. Anderson et al.

    Structural equation modeling in practice: a review and recommended two-step approach

    Psychological Bulletin

    (1988)
  • Anderson, J. C., & McGee, R. (1994). Comorbidity of depression in children and adolescents. In: W. M. Reynolds & H. F....
  • Cited by (0)

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