Introduction
Avoidance has always been necessary for survival (e.g., [
1]), encompassing ‘any act or series of actions that enables an individual to avoid or anticipate unpleasant or painful situations, stimuli or events, including conditioned aversive stimuli’ [
2]. Avoidance becomes problematic if the avoided stimuli are benign [
3], or when avoidance become excessive, interfering with daily-life functioning [
4,
5]. Avoidance plays a central role in the development (e.g., [
6]), maintenance (e.g., [
7]) and return of fear [
3], and is considered a hallmark feature of specific fears, broader trait anxiety [
8] and anxiety-related difficulties [
3].
Anxiety is a normal emotional response that signals threat. Anxiety can take many forms, such as worrying about certain topics (e.g., global warming), fearful reactions in response to specific feared stimuli (e.g., spiders). Anxiety can be adaptive for a certain developmental phase or given a certain situation, such as an objective trauma. However, disproportional or enduring anxiety can lead to anxiety-related difficulties or even to anxiety disorders (e.g., [
9]). Moreover, anxiety is a central emotion in anxiety-related disorders such as post-traumatic stress disorder (PTSD).
In the short-term, avoidance reduces feelings of anxiety. However, avoidance prevents children from learning that the anticipated threat does not actually occur, thus negatively reinforcing and maintaining the fear in the long run [
5,
10]. For example, children with a fear of dogs might evade an approaching dog, thus avoiding the perceived threat, alleviating the anxiety in the short-term but sustaining the anxiety in the long-term (i.e., not learning that most dogs are benign and thus staying afraid of dogs). Therefore, in the long run, children most likely remain anxious when responding with avoidance [
11]. Additionally, avoidance can hinder adequate emotional processing and learning [
12]. Moreover, a recent systematic review showed that enduring avoidance is predictive of the chronicity of anxiety disorders [
13]. During exposure-based interventions and treatments, children are encouraged to reduce their avoidance. However, after exposure-based interventions or treatment, returning to avoidance may reestablish fear [
3,
14,
15].
Avoidance is a transdiagnostic factor and active therapeutic target for problems with anxiety, such as anxiety-related disorders and PTSD [
4], where the expression of avoidance can either be behavioral, experiential, or both. Behavioral avoidance has a predominantly overt character and occurs when children physically avoid certain situations that increase their anxiety, such as sleeping over at a friend’s house. Experiential avoidance is more covert in nature and occurs when children avoid or adapt unwanted personal experiences (e.g., painful memories), and contexts associated with these unwanted experiences [
16].
Despite the relevance of avoidance in the etiology and continuity of anxiety-related difficulties, convenient measures to assess avoidance in anxious children are scarce. Observational measures, such as Behavioral Avoidance Tests [
17] are prone to biases due to demand characteristics and social desirability, show difficulties with standardization, and are time consuming [
18]. Motion-tracking measures, like the Yale Interactive Kinect Environment Software platform (YIKES, 18), may not possess good cost-to-benefit ratios. Structured interviews, such as the Diagnostic Interview for Mental Disorders in Children and Adolescents (Kinder-DIPS, 19), are time consuming and need trained interviewers. In contrast, questionnaires are convenient, time-efficient measures that possess a good cost-to-benefit ratio.
A number of questionnaires exist to measure avoidance limited to a specific type of anxiety. For example, the Severity Measure for Specific Phobia assesses avoidance related to specific phobia [
20], the Social Anxiety Scale for Children-Revised (SASC-R, 21) and the Social Anxiety Scale for Adolescents (SAS-A, 22) assess avoidance related to social anxiety, and the Screen for Child Anxiety related Emotional Disorders (SCARED, 26, 27) assesses school avoidance. More broadly, the Mutidimensional Anxiety Scale for Children (MASC, 23) and MASC-2 [
24] measure harm avoidance [
25]. A different type of questionnaire on anxiety related avoidance is the Anxiety and Avoidance Scale for Children (AVAC, 28). The AVAC includes only individualized items, making it highly suitable to monitor individual changes in avoidance. The child and parent are asked to report three of the child’s most anxiety provoking situations, to specify the child’s avoidance behavior in each of these situations, and to rate the severity of the child’s anxiety and avoidance in these three situations. Although valuable, none of these questionnaires can be applied to all types of anxiety related avoidance and are suitable to examine individual as well as interindividual changes in avoidance.
In contrast, the Child Avoidance Measure (CAM, 29) is a questionnaire that assesses the level of avoidance related to all types of anxiety and can be used to measure individual and interindividual changes in avoidance. It measures active avoidance, passive avoidance (i.e., overt and covert) and refusal. The questionnaire can be completed by the child, i.e., the Child Avoidance Measure-Self Report (CAMS), as well as by the parent, i.e., the Child Avoidance Measure-Parent Report (CAMP). The original CAMS and CAMP possess good internal and test-retest reliability, concurrent and criterion validity, and treatment sensitivity [
29]. In the current study, we sought to examine the psychometric properties of the Dutch version of the CAMS questionnaires. We expected to confirm the sound psychometric properties of the CAMS using a Dutch version in a Dutch population.
Results
Descriptive Statistics
The community sample (
n = 63) consisted of 41 girls (65%) and 22 boys (35%), with a mean age of 10.38 (
SD = 1.57). The high-anxious sample (
n = 92) consisted of 50 girls (54%) and 42 boys (46%), with a mean age of 9.77 (
SD = 1.55). Both samples included children from various parts of the Netherlands. We checked all of the data for possible gender and age effects. Girls (
M = 36.31,
SD = 16.54) had significantly higher self-report scores on the YAM-5 at baseline than boys (
M = 22.24,
SD = 12.84),
t(58) = -3.143,
p = .003, and after 30 days (Girls:
M = 31.44,
SD = 15.83; Boys:
M = 18.89,
SD = 16.56),
t(48) = -2.58,
p = .013. In addition, parents (CAMP) rated the avoidance scores at baseline higher for girls (
M = 13.05,
SD = 4.68) than for boys (
M = 10.18,
SD = 3.90),
t(61) = -2.10,
p = .040. No other gender effects in either sample were found, all
p’s > 0.10, nor any age effects, all
p’s > 0.05. We also checked the normality of the data. All variables had a distribution that approximated normality, except for daily avoidance with skewness = 2.043, (SE = 0.304), and kurtosis = 4.66 (SE = 0.599). Table
2 shows the descriptive statistics and correlations between variables.
Table 2
Associations between the included constructs at pre- and posttest in the Community Sample
CAMSa baseb
| - | | | | | | | | |
CAMPc base | 0.38** | - | | | | | | | |
AFQ-Yd base | 0.37** | 0.26* | - | | | | | | |
YAM-5e base | 0.22 | 0.34** | 0.57** | - | | | | | |
ADf
| 0.20 | 0.09 | 0.07 | 0.07 | - | | | | |
CAMS postg
| 0.59** | 0.32* | 0.27* | − 0.02 | 0.39** | - | | | |
CAMP post | 0.36** | 0.54** | 0.13 | 0.15 | 0.09 | 0.44** | - | | |
AFQ-Y post | 0.36** | 0.21 | 0.51** | 0.21 | 0.24 | 0.32* | 0.09 | - | |
YAM-5 post | 0.26* | 0.28* | 0.51** | 0.79** | 0.11 | 0.43** | 0.25 | 0.36* | - |
Reliability
In the community sample, the internal consistencies of the CAMS were ⍺ = 0.75 and ICC = 0.74, 95% CI [0.62, 0.83], p < .001 at baseline, and ⍺ = 0.84 and ICC = 0.83, 95% CI [0.75, 0.89], p = .000 after 30 days. The internal consistencies of the CAMP were ⍺ = 0.90 and ICC = 0.89, 95% CI [0.84, 0.93], p = .000 at baseline, and ⍺ = 0.90 and ICC = 0.90, 95% CI [0.86, 0.93], p = .000 after 30 days. The test-retest reliability of the CAMS was ICC = 0.75, 95% CI [0.64, 0.84], p < .001. The test-retest reliability of the CAMP was ICC = 0.90, 95% CI [0.85, 0.93], p = .000. In the high-anxious sample, the internal consistencies of the CAMS were ⍺ = 0.75, and ICC = 0.71, 95% CI [0.61, 0.79], p = .000.
Validity
The correlation between child and parent report was ICC = 0.26, 95% CI [0.17, 0.38], p < .001, at baseline. After 30 days, the child-parent correspondence was ICC = 0.37, 95 CI [0.27, 0.49], p = .000.
With respect to the convergent validity in the community sample, results showed significant positive correlations between CAMS and AFQ-Y8 scores both at baseline r = .37, p = .005, and after 30 days, r = .32, p = .015. Regarding the convergent validity in the high-anxious sample, we found no association between the CAMS scores and the avoidance score of the SCID-5-Junior, r = .17, p = .113.
Regarding the ecological validity there were no significant correlations between the baseline CAMS or CAMP scores and daily avoidance, both p’s > 0.10. However, CAMS scores at the end of the 30-day period had a significant positive correlation with daily avoidance, r = .39, p = .003.
Finally, regarding testing the discriminant validity between the community and high-anxious sample, it appeared that the community sample (M = 11.68, SD = 4.75) had significantly lower avoidance scores than the high-anxious sample (M = 14.04, SD = 4.71), t(174 ) = 3.18, p = .002; d = 0.50. Findings were not different after normalizing scores.
Discussion
Avoidance is key in the development, maintenance and renewal of fear, and is considered a hallmark feature in child anxiety. Various interventions and treatments for childhood anxiety aim at reducing avoidance (e.g., exposure). Of the available Dutch language questionnaires to measure specific types of anxiety related avoidance (e.g., [
21-
24,
26,
27]), none are designed to measure avoidance across all types of anxiety presentations. Therefore, this study examined the psychometric properties of the Dutch version of the Child Avoidance Measure Self-report (CAMS, 19) in community and high-anxiety children in the Netherlands.
Overall, we confirmed the sound psychometric properties of the original CAMS/CAMP [
29], using the Dutch translation. With respect to the reliability, the internal consistencies of the child-version of the CAM (CAMS) ranged from acceptable to good and the test-retest reliability was good. The internal consistencies of the parent-version (CAMP) ranged from good to excellent and the test-retest reliability was excellent.
Regarding the validity of the child-version of the CAM, results were mixed but encouraging. We found a small association between the children and parents as informants. Although this may seem weaker than one might expect, it is in line with other studies investigating child-parent agreement in reporting emotional and behavioural problems [
43]. Generally, the more observable a behaviour is, the higher the agreement between self- and proxy reports. Possibly, due to the more covert avoidance items in the CAM, the agreement between the informants may be weaker. As such, it is of importance to include child-reports in less observable child problems, such as avoidance.
The assessment of the convergent validity revealed a significant moderate positive relation between the CAMS and the AFQ-Y8. Though generally speaking the cut-off showing adequate convergent validity is a strong correlation (i.e., > 0.50) [
44], we consider the current correlations (0.37 and 0.32 on baseline and post-test, respectively) as encouraging results for supporting validity, as the AFQ-Y8 measures only experiential avoidance whereas the CAMS measures a more broadly defined construct of avoidance, including not only experiential but also behavioural avoidance. However, the avoidance levels assessed with the CAMS did not converge with the avoidance levels assessed with the diagnostic interview SCID-5-Junior. This is most likely due to the fact that the CAMS assesses overall, daily life avoidance related to anxiety, whereas the diagnostic tool examines avoidance only after the child reports severe anxiety. Additionally, the CAMS examines the level of avoidance, whereas the diagnostic tool only assesses whether avoidance is present (yes/no). This may indicate that the avoidance levels of the SCID-5-Junior reflect the diversity of anxiety problems (i.e., being anxious about and avoiding a variety of entities), rather than the depth of the avoidance symptoms.
With respect to the ecological validity, the baseline CAMS was not related to daily avoidance. Though, after completing the daily avoidance diary for 30 days, the CAMS had a moderate positive relation with daily avoidance. Similarly, the baseline CAMS was not related to child anxiety, whereas we found a moderate positive relation between the CAMS and child anxiety after filling in the daily avoidance diary for 30 days. Interestingly, whereas the CAMS avoidance levels within the community sample were not related to baseline scores of daily avoidance or child anxiety, there were positive associations between the CAMS avoidance levels on the one hand and daily avoidance and child anxiety on the other hand after 30 days. We want to tentatively suggest that an increased awareness and understanding of the concept of avoidance over the 30 days may explain the presence of a positive associations after 30 days, while these variables were unrelated at baseline. That is, filling in the avoidance diaries for 30 days may have increased the children’s awareness and understanding of the concept of avoidance. Measurement reactivity is particularly common in diary studies [
45], and response shifts towards descriptions that are more realistic or accurate have been reported in diary studies (e.g., [
46]).
Finally, the community sample had lower levels of avoidance than the high-anxious sample. The instrument thus seems to discriminate the levels of avoidance in children who exhibit anxiety problems and those who do not. This finding supports the CAMS’ discriminant validity.
Theoretical and Clinical Implications
This results of this study support the validity of using the CAMS questionnaire in community samples as well as high-anxious samples. Also, we demonstrated the usefulness of the Dutch version of the CAMS. An important theoretical and clinical observation we made, was the poor agreement between levels of avoidance measured with the avoidance questionnaire and the diagnostic tool. If clinicians want to gain insight into children’s avoidance levels, using an avoidance questionnaire in addition to a diagnostic interview seems to be of added value. Future studies are needed to gain more insight into the unique information resulting from using questionnaires or diagnostic interviews.
Limitations
The findings of this study should be interpreted in light of its limitations. First of all, we did not include a sample of clinically anxious children, which limits the generalizability of the findings. Nevertheless, we did include a sample of children from the general population, as well as a sample of children who were high-anxious. In both samples, the psychometric properties are promising, which is encouraging. Second, the results of the avoidance diary should be interpreted with care. Although the avoidance diary was associated with the CAMS at day 30, supporting the diary’s validity, the diary seemed to be a relatively insensitive measure for daily child avoidance. That is, most children reported little to no avoidance over the 30-day period. This may be due to the dichotomous answering option (yes/no avoidance), which could have led children to report only severe instances of avoidance. Third, the 30-day period might not have been long enough to capture avoidance in a community sample. Since a diary is worthwhile to gaining insight into the ecological validity of a questionnaire in a relatively easy and non-invasive manner, developing more extensive diaries (e.g., including daily avoidance rating scales) is an interesting venue, as well as using a diary in a high- or clinically-anxious population where avoidance in daily life is more prevalent. Fourth, although the sample sizes are large enough according to the power analysis, we believe that a larger sample size would be valuable for psychometric studies on assessment tools. Fifth, the community sample was recruited via convenience sampling, whereas the ‘high-anxious’ sample was not, which could result in differences between groups that we are not able to identify or correct.
Summary
Avoidance is considered a hallmark feature in child anxiety, but convenient measures are scarce. This study examined the psychometric properties of the Child Avoidance Measure (CAM) in a Dutch population, focusing mainly on the child-version. We included children 8 to 13 years old from the community sample as well as a sample of high-anxious children. Regarding the child-version, the internal consistencies were acceptable to good, and its test-retest reliability moderate. The validity analyses showed encouraging results. High-anxious children had higher avoidance scores than children from a community sample. Regarding the parent-version, both the internal consistency and test-retest validity were excellent. Overall, this study supported the sound psychometric properties and usefulness of the CAM. Future studies should focus on the psychometric properties of the Dutch CAM in a clinical sample, assess its ecological validity more extensively, and examine more psychometric features of the parent-version.
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