PCR66 How Would the Choice of the Multi-Attribute Utility Instrument Affect the Cost-Effectiveness of Cancer Interventions? A Comparison of the FACT-8D and the AQoL

To compare the performance of the Functional Assessment of Cancer Therapy-Eight Dimension (FACT-8D), a cancer-specific multi-attribute utility instrument derived from the FACT-General (FACT-G) questionnaire, with the Assessment of Quality of Life (AQoL) as a generic instrument. Health-related quality of life (HRQoL) data were drawn from a randomised controlled trial of a home-based rehabilitation program compared to usual care in lung cancer (ANZCTRN 12614001268639). Both the AQoL and the FACT-Lung (FACT-L) were adminsitered at baseline, 9 weeks and 6 months of the trial. The FACT-8D utility values were derived using the algorithm developed by King et al (2021). The utility values from the two instruments were compared and assessed for correlation and agreement at baseline, and the quality-adjusted life-years (QALYs) gained over time was calculated. A cost-utility analysis from an Australian health system perspective was conducted. At baseline, mean utility values derived from the FACT-8D (0.68, 95% CI: 0.63-0.73) were higher and statistically different compared to the values from the AQoL (0.66, 95% CI: 0.61-0.71). The correlation between the two instruments was moderate (Pearson’s correlation = 0.69); but the agreement was low (Lin’s concordance correlation coefficient = 0.69). The intervention was found to be less effective but cost saving compared with usual care. There was a slight difference in the QALYs gained when using the FACT-8D over the AQoL (-0.009 vs -0.011), and a higher incremental net monetary benefit ($1,476 vs $1,388). This is the first study to compare the FACT-8D and the AQoL. There was divergence in the utility values and QALYs estimated using the two instruments; however, the intervention was cost-effective irrespective of the instrument used. Deriving the FACT-8D from the FACT-G or related FACIT questionnaire may offer an alternative and efficient method to measure HRQL in cancer trials; however, further testing of the instrument in practice is required.