Psychometric (unweighted) or Utility (weighted)?
As generic instruments, the AQoL questionnaires are applicable to all public health and clinical interventions, and can be used in different ways.
As a 'psychometric' measure: Each instrument can be used to derive a simple psychometric score for health related quality of life (HRQoL) and to provide profile scores on the different dimensions or items of the descriptive systems. The score is derived by adding the unweighted response order of each question.
As a 'utility' measure: When utilities are computed, these instruments can provide dimension scores and an overall index of the health state utility which can be used in economic evaluations, and specifically, cost-utility analysis requiring the computation of quality-adjusted life years (QALYs). The ‘utilities’ are, in effect, preference weights and final utility scores should reflect peoples’ preferences more accurately than unweighted aggregates.
The following example question about feeling sad demonstrates the two ways of scoring:
Please choose the appropriate instrument, statistical package and instructions, then download the algorithms to calculate your scores.
Utility algorithms (weighted)
Right click on the hyperlink, as indicated below, to access the zip files containing the algorithms for instruments as required
AQoL-8D utility algorithms
This zip file contains an instruction page and the SPSS and STATA algorithms for AQoL-8D
VisQoL Scoring psychometric and standardised - Excel
NB: Correction to the AQoL-6D algorithms
AQoL-6D for adults versus AQol-6D ADOLESCENT Utility Scores
In the OPIC study adolescent utilities for Australia, New Zealand, Fiji and Tonga were derived by adjusting the AQoL-6D scores for Australian adults. The original 6D utility study estimated 9 separate models.
The aqol.com.au website now recommends the scoring algorithm reproduced from model 6 for adults and the algorithm from model 1 for adolescents. This implies that adolescent scores calculated from model 1 should not, in principle, be compared with adult scores calculated from model 6 (or model 9, the original model recommended in Richardson et al 2007).
Model 1 scores may be obtained from the formula:
AQoL-6D (model 1) = [AQoL-6D (Multiplicative)]0.59
This may be further adjusted to obtain the adolescent scores described in Moodie et al. (2010).