OBJECTIVES

: Our main aim was to quantify the health state utility values (HSUVs) for Australians with Idiopathic Pulmonary Fibrosis (IPF) and to identify the factors affecting these HSUVs.

METHODS

Participants from the Australian IPF Registry (AIPFR), with data on EuroQoL five dimension – five level (EQ-5D-5L) profiles were included. As no published Australian value set for the EQ-5D-5L existed, we used a methodology described by van Hout et al to map the EQ-5D-5L responses to EQ-5D-3L. The HSUVs were calculated using the ‘EQ-5D’ package for R (version 3.6.2). Pulmonary function tests (PFTs) were used to classify disease severity and three systems for classification were used: Gender, Age, Physiology Staging (GAP); Composite Physiological Index (CPI); and Forced Vital Capacity percent predicted (FVC%). Stepwise multivariate linear regression was then used to assess the relationship between HSUVs, disease severity, comorbidities, types of treatment, age and sex. Statistical significance was set as a p-value ≤0.05 (two-tailed).

RESULTS

: A total of 155 participants provided data for the analysis. HSUVs ranged from 0.01 to 1.00. Mean HSUVs for all participants was 0.70 (95% CI: 0.67−0.72). In general, HSUVs decreased with increasing disease severity under all disease classification systems. Persons in the youngest (<60 years) and oldest (>80 years) age groups had the lowest mean HSUVs, 0.67. Mean HSUVs were slightly lower in females than in males, 0.66 (0.62−0.72) and 0.71 (0.68−0.74). Multivariable linear regression also demonstrated a negative association between HSUVs and number of comorbidities, ranging from 0.11 to 0.12 units lower with >2 comorbidities.

CONCLUSIONS

: We have generated HSUVs for Australians with IPF and demonstrated that disease severity and having more than two comorbidities was associated with lower HSUV. Our findings support early diagnosis and treatment to slow or prevent IPF progression; and identification and treatment of associated comorbidities to potentially improve HRQL of people with IPF.