Norwegian version of the rating anxiety in dementia scale (RAID-N): a validity and reliability study

Dementia-specific anxiety scales in the Norwegian language are lacking; the aim of this study was to investigate the validity and inter-rater reliability of a Norwegian version of the Rating Anxiety in Dementia (RAID-N) scale.

The validity of the RAID-N was tested in a sample of 101 patients with dementia from seven Norwegian nursing homes. One psychogeriatrician (n = 50) or a physician with long experience with nursing home patients (n = 51) 'blind' to the RAID-N score diagnosed anxiety according to DSM-5 criteria of generalised anxiety disorder (GAD). A receiver operating characteristic (ROC) analysis assessed the best cut-off point for the RAID-N, and the area under the curve (AUC) was calculated. Inter-rater reliability was tested in a subgroup of 53 patients by intraclass correlation (ICC) and Cohen's kappa.

Twenty-eight of 101 (27.7%) met the GAD criteria. The mean RAID-N score for patients with GAD was 16.1 (SD 6.3) and without GAD, 8.8 (SD 6.5) (p < 0.001). A cut-off score of ≥12 on the RAID-N gave a sensitivity of 82.1%, specificity of 70.0%, and 73.3% accuracy in identifying clinically significant GAD in patients with dementia. Inter-rater reliability on overall RAID-N items was good (ICC = 0.82), Cohen's kappa was 0.58 for total RAID-N score, with satisfactory internal consistency (Cronbach's alpha = 0.81).

The RAID-N has fairly good validity and inter-rater reliability, and could be useful to assess GAD in patients with dementia. Further studies should investigate the optimal RAID-N cut-off score in different settings.