Background

Idiopathic pulmonary fibrosis (IPF) is a debilitating chronic lung disease with a high symptom burden, which has a substantial impact on health-related quality of life (HRQoL). Our study aimed to assess the performance of the EuroQol five-dimension (EQ-5D-5L) and the Assessment of Quality of Life- eight-dimension (AQoL-8D) questionnaires in measuring HRQoL as utility values (HSUVs) in an Australian IPF cohort.

Methods

Data were collected from participants of the Australian IPF Registry (AIPFR) using self-administered surveys which included the EQ-5D-5L and the AQoL-8D. Clinical data and disease specific HRQoL instruments were collected from the AIPFR. Performance of the two instruments was evaluated based on questionnaire practicality, agreement between the two instruments and test performance (internal and construct validity).

Results

Overall completion rates for the EQ-5D-5L and AQoL-8D were 96% and 85% respectively. Mean (median) HSUVs were 0.65 (0.70) and 0.69 (0.72) for the EQ-5D-5L and AQoL-8D respectively. There was reasonable agreement between the two instruments based on the Bland-Altman plot mean difference (-0.04) and intraclass correlation coefficient (0.84), however there were some differences. A larger range of values was observed with the EQ-5D-5L when compared to the AQOL-8D (-0.57-1.00 vs 0.16-1.00). The EQ-5D-5L had a greater divergent sensitivity and efficacy in relation to assessing HSUVs between clinical groupings. The AQoL-8D however had a higher sensitivity to measure psychosocial aspects of HRQoL in IPF.

Conclusion

The EQ-5D-5L exhibited better performance when compared to AQoL-8D in persons with IPF. This may be attributable to the high symptom burden which is physically debilitating to which the EQ-5D-5L may be more sensitive.