Face validity and inter-rater reliability of the Danish version of the modified Yale Preoperative Anxiety Scale.

INTRODUCTION Preoperative anxiety is common in children and it is associated with an adverse post-operative outcome. The modified Yale Preoperative Anxiety Scale (m-YPAS) was developed to assess preoperative anxiety in children. The purpose of this study was to translate and adapt the m-YPAS to Danish cultural and linguistic conditions and to test its face validity and inter-rater reliability in a clinical setting. MATERIAL AND METHODS Translation was done in accordance with the WHO guidelines. Face validity and linguistic challenges were resolved in a focus group with five nurse anaesthetists. Inter-rater reliability for the subscales in the m-YPAS was determined at two different time points by using weighted kappa (κw) statistics, whereas agreement on the overall weighted scores was calculated using the intraclass correlation coefficient (ICC). The inter-rater reliability test was done by a paediatric anaesthesiologist consultant, a psychiatrist and the first author. RESULTS The Danish version of the m-YPAS was considered suitable and its face validity was satisfactory. Inter-rater reliability analysis revealed that inter-observer agreement among three independent raters was good (induction 1: κw: 0.63-0.98, ICC = 0.92; induction 2: κw: 0.72-0.96, ICC = 0.92). CONCLUSION Standardised and validated assessment tools are needed to evaluate interventions to reduce preoperative anxiety in children. A Danish version of the m-YPAS now exists, and preliminary testing has demonstrated a satisfactory face validity and inter-rater reliability. FUNDING The study was supported by grants from TrygFonden (Grant number: j.no.7-11-1292). TRIAL REGISTRATION The Danish Data Protection Agency, the Central Denmark Region, has approved the study (j.no.: 2007-58-0010).