EQ-5D-3L full health state discriminates between drug and placebo in clinical trials of systemic lupus erythematosus.

OBJECTIVES

The objectives of this study were to investigate the discriminative ability of EQ-5D-3L full health state (FHS) in clinical trials of SLE, and to identify factors associated with FHS after treatment.

METHODS

Data from the BLISS-52 (NCT00424476) and BLISS-76 (NCT00410384) trials of belimumab (N = 1684) were utilized. FHS was defined as a response of no problems in all five EQ-5D-3L dimensions, yielding an index score of 1. The Pearson's χ2 or Fisher's exact test was employed for comparisons, and logistic regression for adjustments and assessment of independence.

RESULTS

We demonstrated higher EQ-5D-3L FHS frequencies among patients given standard therapy (ST) plus the licensed belimumab dose vs ST alone (26.1% vs 19.4%; P = 0.001; week 52), and within SRI-4 responders vs non-responders (27.0% vs 19.8%; P < 0.001; week 52) from weeks 36 to 52. In multivariable regression analysis, SLEDAI-2K (OR: 0.90; 95% CI: 0.87, 0.94; P < 0.001) and SLICC/ACR Damage Index (OR: 0.79; 95% CI: 0.69, 0.91; P = 0.001) scores were independently associated with lower FHS frequencies at week 52, while adding monthly infusions of belimumab 10 mg/kg to ST favoured FHS perception (OR: 1.60; 95% CI: 1.15, 2.24; P = 0.006). Add-on belimumab 10 mg/kg yielded higher FHS frequencies in antimalarial users vs non-users (29.9% vs 20.1%; P = 0.011), and in anti-dsDNA- and anti-Sm- positive vs negative patients (31.4% vs 13.4%; P < 0.001 and 33.0% vs 22.6%; P = 0.010, respectively), whereas no significant differences were observed in patients given ST alone.

CONCLUSION

EQ-5D-3L FHS distinguished belimumab from placebo and responders from non-responders, and exhibited known-group validity in subgroup analysis. FHS may prove a useful patient-reported outcome in SLE studies.