Principal component analysis of the Norwegian version of the quality of life in late-stage dementia scale

Dement Geriatr Cogn Disord. 2014;37(5-6):265-75. doi: 10.1159/000356497. Epub 2013 Dec 14.

Abstract

Aims: To investigate which factors the Quality of Life in Late-Stage Dementia (QUALID) scale holds when used among people with dementia (pwd) in nursing homes and to find out how the symptom load varies across the different severity levels of dementia.

Methods: We included 661 pwd [mean age ± SD, 85.3 ± 8.6 years; 71.4% women]. The QUALID and the Clinical Dementia Rating (CDR) scale were applied. A principal component analysis (PCA) with varimax rotation and Kaiser normalization was applied to test the factor structure. Nonparametric analyses were applied to examine differences of symptom load across the three CDR groups.

Results: The mean QUALID score was 21.5 (±7.1), and the CDR scores of the three groups were 1 in 22.5%, 2 in 33.6% and 3 in 43.9%. The results of the statistical measures employed were the following: Crohnbach's α of QUALID, 0.74; Bartlett's test of sphericity, p <0.001; the Kaiser-Meyer-Olkin measure, 0.77. The PCA analysis resulted in three components accounting for 53% of the variance. The first component was 'tension' ('facial expression of discomfort', 'appears physically uncomfortable', 'verbalization suggests discomfort', 'being irritable and aggressive', 'appears calm', Crohnbach's α = 0.69), the second was 'well-being' ('smiles', 'enjoys eating', 'enjoys touching/being touched', 'enjoys social interaction', Crohnbach's α = 0.62) and the third was 'sadness' ('appears sad', 'cries', 'facial expression of discomfort', Crohnbach's α 0.65). The mean score on the components 'tension' and 'well-being' increased significantly with increasing severity levels of dementia.

Conclusion: Three components of quality of life (qol) were identified. Qol decreased with increasing severity of dementia.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Dementia / diagnosis
  • Dementia / psychology*
  • Female
  • Humans
  • Male
  • Nursing Homes*
  • Principal Component Analysis*
  • Quality of Life / psychology*
  • Severity of Illness Index