Dental fear and BII fear

The CFSS-DS is a validated psychometric instrument for assessing dental fear in children which has been widely used, and found to have good reliability and validity in different populations, including that of Scandinavia (4, 43, 74, 98, 99). The instrument may be used in two different versions, either by self-rating by the child or by parental ratings. Self-ratings by the children were used in this thesis to strengthen the reliability and validity, as scales completed by parents/guardians have shown moderate agreement between child and parental ratings on self-reports (16). For the child version, cut-off scores between 37 and 42 have been used (16, 48, 100). In the present thesis, the score above 38 was chosen for both Study I and II, similar to the cut-off score used in a Swedish study (containing a small sample with child self-ratings) (16). Another study used one standard deviation (SD) above the mean as a cut-off value when children completed the CFSS-DS (97). If this method had been used in the present study, it would have lowered the cut-off value and consequently would have increased the prevalence of dental fear. Furthermore, different cut-off scores by age and sex for the parent rated CFSS-DS scale have revealed cut-off scores lower than the standard cut-off scores (16). Accordingly, the use of standard

cut-off scores in the prevalence estimation of dental fear might have underestimated the fear level.

The IS-c and MQ-c assessing fear of injections and blood-injury fear in children, respectively, were constructed and validated in a Swedish sample of 8- to 17-year-old children and adolescents (N=677). In the study, norm data were obtained and psychometric properties were evaluated (42). Both scales had excellent

psychometric properties and were found to be appropriate for use both in research and as a clinical tool. A limitation was that the scales did not have a validated cut-off score for measuring a high level of fear.

The IS-c, MQ-c and CFSS-DS were all in Norwegian. The Norwegian versions were based on the Swedish versions, as the two Scandinavian languages are closely related to each other. The scales had been translated from Swedish to Norwegian and were then back-translated.

Even though psychometric self-report scales are recommended for assessing fear in children, and widely used, the validity of using self-reported scales in 10- to 16-year-olds must be interpreted with caution. Their responses depend not only on their age, but also on their stages of development in cognitive, social and emotional terms (101).

4.1.2.3 Behavioural Avoidance Test

The BAT (Paper 3, Table 1) was used to measure behavioural changes, and has previously been used in adults (67). Similar versions adapted for specific phobias including other BII phobias have been utilized for both children and adults (66, 70).

As avoidance is known to be one among other important diagnostic criteria of a phobia, measures of change in avoidance behaviour are considered useful for assessing this disorder. However, the BAT used in this study involved the invasive and possibly painful procedure of intra-oral injection. Combined with the lack of an established therapeutic alliance to the external dentist, the test may be experienced

differently for children than for adults, possibly due to differences in cognitive development. As trust and a therapeutic alliance are key aspects during CBT (63, 101), further research should evaluate whether the BAT for intra-oral injection phobia in children is developmentally appropriate.

4.1.2.4 Cognitions during the BAT

The "Cognitions during the BAT" was assessed in order to evaluate cognitive changes that occurred together with behavioural alterations after teatment. Although the reliability and validity of the "Cognitions during the BAT" was found satisfactory in adults (67), the questionnaire was not necessarily developmentally appropriate for children. One may speculate as to whether some of the youngest children may have had difficulties differentiating between the present situation and future events when responding to the questionnaire. This could possibly have led to conservative results of the positive and negative cognitions during the test.

4.1.2.5 Time since last intra-oral injection

The variable "time since last intra-oral injection" introduces possible recall bias.

Therefore, the response options <1 year ago and ≥1 year ago were combined, yielding the variable "experiences with dental injections". The response options were

dichotomized into "yes" and "no", to limit recall bias and increase reliability. Most of the pupils (59.4%) (Study I) could remember having experienced an intra-oral injection. Correspondingly, the PDS in Hordaland County reported the percentage of 10- to 16-year-olds in 2014with no prior caries experience to be approximately 47%.

This percentage adds support to the validity of the pupils reported experience with intra-oral injections. However, among those who reported not having experienced an intra-oral injection or those who did not recall one, some may actually have received intra-oral injections. The recollections by these children may be influenced by a variety of factors. If the situation was not perceived as particularly fearsome, the

children could have forgotten about it. On the other hand, if the situation was perceived as extremely fearsome, some children could have supplanted the experience or could have dissociated, resulting in not remembering the intra-oral injection experience (13).