A parent-report measure of children’s anxiety: psychometric properties and comparison with child-report in a clinic and normal sample

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Abstract

This study examined the psychometric properties of the parent version of the Spence Children’s Anxiety Scale (SCAS-P); 484 parents of anxiety disordered children and 261 parents in a normal control group participated in the study. Results of confirmatory factor analysis provided support for six intercorrelated factors, that corresponded with the child self-report as well as with the classification of anxiety disorders by DSM-IV (namely separation anxiety, generalized anxiety, social phobia, panic/agoraphobia, obsessive–compulsive disorder, and fear of physical injuries). A post-hoc model in which generalized anxiety functioned as the higher order factor for the other five factors described the data equally well. The reliability of the subscales was satisfactory to excellent. Evidence was found for both convergent and divergent validity: the measure correlated well with the parent report for internalizing symptoms, and lower with externalizing symptoms. Parent–child agreement ranged from 0.41 to 0.66 in the anxiety-disordered group, and from 0.23 to 0.60 in the control group. The measure differentiated significantly between anxiety-disordered children versus controls, and also between the different anxiety disorders except GAD. The SCAS-P is recommended as a screening instrument for normal children and as a diagnostic instrument in clinical settings.

Introduction

In the past few years, research on the assessment of childhood anxiety has focused on constructing child self-report questionnaires that are related to the commonly used classification system of DSM-IV (American Psychiatric Association, 1994). Prior to this, questionnaires did not examine specific anxiety disorders, but were typically designed to measure indicators of anxiety in general. Moreover, they were generally derived from adult anxiety measures rather than being based on child specific items.

The need for a child self-report questionnaire following the DSM-classification was evident and led to the development of measures such as the Spence Children’s Anxiety Scale (SCAS; Spence, 1997) and the Screen for Child Anxiety Related Emotional Disorders (SCARED; Birmaher et al., 1997). Both instruments have recently been studied on their psychometric qualities, both separately as well as in relation to each other. Satisfactory reliability is a basic and essential requirement for an assessment instrument. For individual assessment purposes, Cronbach’s alpha’s of at least 0.80 have been recommended, whereas for research purposes reliabilities of 0.70 or higher may suffice (Nunnally, 1978). Further, a sound instrument should preferably show different types of validity. Convergent validity should be reflected by relatively high correlations with instruments that are meant to measure similar constructs whereas divergent validity should be demonstrated by relatively low correlations with instruments measuring other variables. In addition, clinical practice requires that an instrument can differentiate between anxiety disorders and normal controls, and ideally also between the distinct anxiety disorders.

The results for the SCAS and the SCARED produced support for the classification of anxiety disorders according to the DSM-IV and demonstrated their psychometric properties to be acceptable (Essau, Muris and Ederer, 2002, Muris, Merkelbach, Ollendick, King and Bogie, 2002).

Although the SCAS and the SCARED display many similarities, they also show some differences. First, the SCAS was developed as a screening instrument in normal populations, whereas the SCARED was developed in clinical populations. Second, the SCAS contains 38 items and was intended to measure symptoms of the following DSM-IV anxiety disorders: (1) panic disorder/agoraphobia, (2) generalized anxiety disorder, (3) social phobia, (4) separation anxiety disorder, (5) obsessive–compulsive disorder, and (6) some specific fears, mainly fear of physical injury/animals. The original SCARED, consisting of 85 items and subsequently reduced to 41 items (Birmaher et al., 1997), was developed to measure symptoms of (1) panic disorder, (2) generalized anxiety disorder, (3) social phobia, (4) separation anxiety disorder and (5) school phobia (the latter not being a DSM-IV anxiety disorder). So, despite fewer items, the SCAS shows a broader scope and a closer connection with the DSM-IV structure than the original version of the SCARED. This situation inspired some researchers (Muris, Merkelbach, Van Brakel and Mayer, 1999, Muris, Schmidt and Merckelbach, 2000) to present adaptations of the SCARED, including 66 items, with symptoms of obsessive–compulsive disorder and PTSS added, but in recent studies only the 41-item, five subscale version is used. Third, the correlation between the social phobia subscales of both questionnaires appeared to be unexpectedly low (r=0.37 in Muris et al., 1999; r=0.58 in Muris et al., 2002; r=0.59 in Essau et al., 2002), suggesting that they measure different aspects of social phobic fears; the SCARED predominantly measures fear of meeting unfamiliar people, whereas the social phobia items in the SCAS are more closely related to the DSM-IV social phobia criteria, such as fear of social or performance situations and fear of negative evaluation (Essau et al., 2002). Finally, the SCAS is rated on a four-point scale with a broader range of possible answers (ranging from 0=never to 3=always), while the present 41-item version of the SCARED is rated on a three-point scale (0=almost never, 1=sometimes, 2=often). In sum, both questionnaires have their own merits for the assessment of anxiety symptoms, although the SCAS seems to be broader in scope and in range in severity of symptoms.

Both measures are, however, limited to child self-report. In the assessment of childhood disorders, it is both common and recommended to include multiple informants, most commonly children, parents and teachers. Each informant may contribute information about different aspects of the disorder, thus complementing each other. Diagnostic interviews most often include both parents and children (e.g. the Anxiety Disorders Interview Schedule Child and Parent Version: ADIS-C/P; Albano & Silverman, 1994). Also, some well-known and widely used ‘general’ child behavior questionnaires have both child and parent versions and include some items relating to anxiety (e.g. the Youth Self Report and the Child Behavior Checklist: YSR and CBCL; Achenbach, 1991). However, both parent diagnostic interviews, such as the ADIS-C/P and more general parent questionnaires for child behavior, such as the CBCL, have their limitations in the clinical assessment of childhood anxiety. Structured interviews are time-consuming and parent questionnaires such as the CBCL do not provide sufficient detail regarding specific symptoms of anxiety disorders. There is a need for a relatively quick, but sufficiently detailed, reliable and valid parent questionnaire that provides a screen to identify children and adolescents who show high levels of anxiety symptoms across a range of anxiety disorders, and for whom a more detailed structured, clinical interview may then be warranted.

The issue of agreement between parent and child report is notoriously problematic in clinical assessment, with correlations as low as 0.25 for parent–child agreement for some measures of child behavior problems (Achenbach, McConaughty, & Howell, 1987). Parent–child agreement was found to be larger when the behavior is observable (Jensen, Traylor, Xenakis and Davis, 1988, March, Parker, Sullivan and Stallings, 1997), and to be smaller for internalizing symptoms than for externalizing behavior (Rey, Schrader, & Morris-Yates, 1992). In line with this, Birmaher et al. (1997) published some data about a parent version of the SCARED and reported a relatively low correspondence between parent and child: r=0.33 for the total scale, with the subscales ranging from r=0.20 for social phobia to 0.47 for SAD.

With regard to age, studies show contradictory findings, but Achenbach et al. (1987) concluded that parent child agreement is higher for younger children than for adolescents. Similarly, within the field of anxiety disorders lower age has been associated with higher parent–child agreement (Rapee, Barrett, Dadds, & Evans, 1994).

Low correlations between child and parent reports do not automatically lead to the conclusion that the validity of the instruments is questionable. It must be noted that the measures often correlate well with other measures of the same construct when completed by the same informant. For instance, for the SCAS (child questionnaire), convergent validity was high with regard to another child self-report on anxiety, but weaker with regard to parental reports of the child’s internalizing and withdrawal symptoms (Spence, 1998). One possible explanation for poor parent–child agreement is that parents and children are not assessing the same underlying constructs when they complete the questionnaire. Perhaps, parents and children conceptualize anxiety differently, leading to a different pattern of responses. Examination of the factorial structure of a measure across different informants may cast some light on this possibility. To date, studies examining the comparability of the factor structure in parent and child measures are scarce. Cole, Hoffman, Tram, and Maxwell (2000) found the factor structure in a global anxiety questionnaire, the Revised Children’s Manifest Anxiety Scale (RCMAS; Reynolds & Richmond, 1978), to be similar in child and parent reports, but not equivalent. They found three-factor solutions in both child and parent report, with two comparable factors, but the third factor was different for the different informants. Cole et al. (2000) suggested that parents and children focus on somewhat different aspects of anxiety and depression, originating from different underlying factors. Given that the RCMAS represents a general measure for child anxiety symptoms, it is possible that a questionnaire such as the SCAS that is based on well-defined clusters of symptoms, will manifest more similar factors across informants.

Given the potential value of a parental questionnaire measure of childhood anxiety, as noted above, the present study was designed to examine the psychometric properties of the parent version of the SCAS. Factor structure and psychometric properties such as internal consistency, convergent and divergent validity were investigated. The study included two samples of Dutch and Australian normal and clinically referred children with a wide age range, different anxiety disorders, and a variety of co-morbid disorders.

Section snippets

Participants

Participants in this study were children aged from 6 to 18 yr and their parents. The groups consisted of anxiety-disordered children and normal controls, from three different settings: Macquarie University and Queensland University in Australia, and the University of Groningen in the Netherlands. The demographic variables of these six subgroups are shown in Table 1. The data from these groups were pooled into one anxiety-disordered group and one normal control group. In addition to comparisons

Preliminary analyses

In the anxiety disordered group, 399 mothers and 322 fathers filled out the questionnaires independently, and 82 parents filled them out together. The normal control group had 40 mother reports, 18 father reports, and 221 reports of parents that filled out the questionnaires together. Father and mother scores on the subscales of the SCAS-P were highly correlated, with correlations varying from 0.51 (generalized anxiety) to 0.73 (separation anxiety). Correlations of 0.50 and higher indicate that

Discussion

This paper presents the psychometric properties of the SCAS-P, a parent completed measure derived from the SCAS, a child questionnaire designed to assess children’s symptoms of anxiety along the structure of the DSM-IV. Based on 484 anxiety disordered children and 264 normal controls, the results suggest that the SCAS-P shows generally good psychometric properties and that it seems highly useful for both research and clinical purposes, especially when combined with the child version. The first

References (46)

  • R.M Rapee et al.

    Reliability of the DSM-III-R childhood anxiety disorders using structured interview: interrater and parent-child agreement

    Journal of the American Academy of Child and Adolescent Psychiatry

    (1994)
  • J.M Rey et al.

    Parent-child agreement on children’s behaviours reported by the Child Behavior Checklist (CBCL)

    Journal of Adolescence

    (1992)
  • S.H Spence et al.

    The structure of anxiety symptoms among preschoolers

    Behavior Research and Therapy

    (2001)
  • S.H Spence

    A measure of anxiety symptoms among children

    Behavior Research and Therapy

    (1998)
  • Abbott, M.J., Gaston, J., & Rapee, R.M. (2002). Bibliotherapy in the treatment of children with anxiety disorders....
  • Achenbach,T.M. (1991). Integrative guide for the 1991 CBCL/4-18, YSR, and TRF profiles. Burlington, VT: University of...
  • T.M Achenbach et al.

    Child/adolescent behavioral and emotional problems: Implications of cross-informant correlations for situational specificity

    Psychological Bulletin

    (1987)
  • A.M Albano et al.

    Anxiety Disorders Interview Schedule for DSM-IV, child version: clinician manual

    (1994)
  • American Psychiatric Association

    Diagnostic and Statistical Manual of Mental Disorders

    (1994)
  • A Boomsma et al.

    The robustness of LISREL modeling revisited

  • P Bouldin et al.

    Utilizing parent report to investigate young children’s fears: a modification of the Fear Survey Schedule for Children-II: a research note

    Journal of Child Psychology and Psychiatry and Allied Disciplines

    (1998)
  • S.R Briggs et al.

    The role of factor analysis in the development and evaluation of personality scales

    Journal of Personality

    (1986)
  • M.W Browne et al.

    Alternative ways of assessing model fit

    Sociological Methods and Research

    (1992)
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