Construction of the descriptive system for the assessment of quality of life AQoL-6D utility instrument

Abstract

BackgroundMulti attribute utility (MAU) instruments are used to include the health related quality of life (HRQoL) in economic evaluations of health programs. Comparative studies suggest different MAU instruments measure related but different constructs. The objective of this paper is to describe the methods employed to achieve content validity in the descriptive system of the Assessment of Quality of Life (AQoL)-6D, MAU instrument.MethodsThe AQoL program introduced the use of psychometric methods in the construction of health related MAU instruments. To develop the AQoL-6D we selected 112 items from previous research, focus groups and expert judgment and administered them to 316 members of the public and 302 hospital patients. The search for content validity across a broad spectrum of health states required both formative and reflective modelling. We employed Exploratory Factor Analysis and Structural Equation Modelling (SEM) to meet these dual requirements.Results and DiscussionThe resulting instrument employs 20 items in a multi-tier descriptive system. Latent dimension variables achieve sensitive descriptions of 6 dimensions which, in turn, combine to form a single latent QoL variable. Diagnostic statistics from the SEM analysis are exceptionally good and confirm the hypothesised structure of the model.ConclusionsThe AQoL-6D descriptive system has good psychometric properties. They imply that the instrument has achieved construct validity and provides a sensitive description of HRQoL. This means that it may be used with confidence for measuring health related quality of life and that it is a suitable basis for modelling utilities for inclusion in the economic evaluation of health programs.

Quality of life impact of cardiovascular and affective conditions among older residents from urban and rural communities

“…Self-rated health outcomes were assessed using the Assessment of Quality of Life (AQoL-6D), a 20-item self-report measure of HRQoL and general functioning [46]. The AQoL-6D forms six domains characterised as ‘Independent living’, ‘Relationships’, ‘Mental health’, ‘Coping’, ‘Pain’, and ‘Senses’ [46].…”

Percutaneous Mitral Valve Repair in a High-risk Australian Series

“…General and heart failure-specific quality of life was measure using the Australian Quality of Life index (6 Domain, AQoL-6D) [18,19] and Minnesota Living with Heart Failure questionnaire (MLWHF) [20], respectively. In both the AQoL-6D and MLWHF, a lower score indicates a better quality of life.…”

Lifetime Affective and Alcohol Use Disorder: Impact of Comorbidity on Current Functioning and Service Use in a Rural Population

“…The AQoL-6D is a 20-item self-report instrument designed to provide a sensitive multidimensional evaluation of health related quality of life across six domains: independent living; relationships, mental health, coping, pain and senses [31]. The physical and psychological components of quality of life were identified as two higher order factors of the AQoL-6D using community samples and considered to have satisfactory construct, concurrent and convergent validity [32].…”

“…Addictions with Co-occurring Problems c) Physical and psychological impairment were measured using the Assessment of Quality of Life -6D scale (AQoL-6D) [31]. The AQoL-6D is a 20-item self-report instrument designed to provide a sensitive multidimensional evaluation of health related quality of life across six domains: independent living; relationships, mental health, coping, pain and senses [31].…”