Recent trends in pirfenidone and nintedanib use for idiopathic pulmonary fibrosis in Australia

The economic burden of idiopathic pulmonary fibrosis in Australia: a cost of illness study

PURPOSE

Idiopathic pulmonary fibrosis (IPF) is a type of interstitial lung disease found mostly in elderly persons, characterized by a high symptom burden and frequent encounters with health services. This study aimed to quantify the economic burden of IPF in Australia with a focus on resource utilization and associated direct costs.

METHODS

Participants were recruited from the Australian IPF Registry (AIPFR) between August 2018 and December 2019. Data on resource utilization and costs were collected via cost diaries and linked administrative data. Clinical data were collected from the AIPFR. A "bottom up" costing methodology was utilized, and the costing was performed from a partial societal perspective focusing primarily on direct medical and non-medical costs. Costs were standardized to 2021 Australian dollars ($).

RESULTS

The average annual total direct costs per person with IPF was $31,655 (95% confidence interval (95% CI): $27,723-$35,757). Extrapolating costs based on prevalence estimates, the total annual costs in Australia are projected to be $299 million (95% CI: $262 million-$338 million). Costs were mainly driven by antifibrotic medication, hospital admissions and medications for comorbidities. Disease severity, comorbidities and antifibrotic medication all had varying impacts on resource utilization and costs.

CONCLUSION

This cost-of-illness study provides the first comprehensive assessment of IPF-related direct costs in Australia, identifies the key cost drivers and provides a framework for future health economic analyses. Additionally, it provided insight into the major cost drivers which include antifibrotic medication, hospital admissions and medications related to comorbidities. Our findings emphasize the importance of the appropriate management of comorbidities in the care of people with IPF as this was one of the main reasons for hospitalizations.

Assessment of health-related quality of life in Australian patients with idiopathic pulmonary fibrosis: a comparison of the EQ-5D-5L and the AQoL-8D

PURPOSE

Idiopathic pulmonary fibrosis (IPF) is a progressive and 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 suitability of the EuroQol five-dimension (EQ-5D-5L) and the Assessment of Quality of Life- eight-dimension (AQoL-8D) questionnaires in measuring HRQoL as health state utility values (HSUVs) in an Australian IPF cohort.

METHODS

Data for estimation of health state utility values (HSUVs) were collected from participants of the Australian IPF Registry (AIPFR) using self-administered surveys which included the EQ-5D-5L and the AQoL-8D. Data on lung function 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 fundamental differences. A larger range of values was observed with the EQ-5D-5L (-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 demonstrated superior 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.