Purpose
The aim of the study was to further validate the Assessment of Quality of life at the End of Life (AQEL) questionnaire, to explore whether conceptually consistent scales could be confirmed and how the instrument relates to other widely used and validated HRQL instruments.
Methods
A total of 106 patients with lung cancer in palliative care completed the 20-item AQEL, the EORTC QLQ-C30, Hospital Anxiety and Depression Scale (HADS), Sense of Coherence (SOC-13) and Social Support Survey (SSS). Construct validity of the AQEL was tested by multitrait scaling, principal components analysis, inter-scale correlations and known-groups comparisons.
Results
Five scales were supported by multitrait scaling: Basic function, Activity, Emotional function, Cognitive function and Existential needs, with satisfactory (>.7) internal consistency for the latter three and intermediate (>.5) for the remaining two. A Social support scale was supported by principal components analysis, but exhibited a low internal consistency. Items on health care issues and physical symptoms worked best as individual items. Expected correlations with other instruments were found for all scales. Activity was sensitive to different levels of functioning as defined by performance status.
Conclusions
This study provided some evidence for the validity of the AQEL and its feasibility in patients with cancer in palliative care.