Background/Purpose Gout flare prevention relies heavily on urate-lowering therapies (ULT) such as allopurinol (ALP) and febuxostat (FBX) but clinical decision-making in patients with moderate to severe chronic kidney disease (CKD) is complicated by significant comorbidity. This study compared healthcare expenditure in ALP and FBX initiators after diagnosis with gout and CKD.
Methods Gout patients (ICD-9-CM 274.xx), aged >18, with concurrent CKD (stage 3, 4), were selected from the MarketScan® databases (January 2009-June 2012) upon ALP or FBX initiation. Patients were followed until disenrollment, discontinuation of the qualifying ULT or use of the alternate study agent. Patients initiating on ALP were subsequently propensity score (PS) matched (1:1) to patients initiating on FBX. Mean monthly healthcare cost (2012 US$) was calculated in aggregate and for 4 disease specific conditions: gout, renal, diabetes (DM) and cardiovascular (CV). Five generalized linear models (GLM) were developed, each controlling for PS, to identify the incremental costs (vs ALP) associated with initiation on FBX after prior exposure to ALP and without prior exposure to ALP.
Results PS matching yielded two cohorts, each with 1,486 patients (65% male, mean (SD) age 67.4 (12.8)). Post-match, 75% of patients had stage 3 CKD, 83% CV disease and 42% DM. The post-match sample was well-balanced on numerous comorbidities and medication exposures with the following exception. Fifty percent of FBX initiators had baseline exposure to ALP while only 3% of ALP initiators had baseline exposure to FBX. There were no differences (p=0.27) in follow-up gout flare frequency. There were no significant differences in mean monthly per patient expenditure, unadjusted, ($1,490 ALP, $1,525 FBX, p=0.8). CV, renal, DM and gout specific costs represented, respectively, 31%, 14.3%, 13% and 10.9% of total cost.
GLM model results suggest that FBX users with recent ALP exposure incurred significantly (p<0.01) more cost than ALP users while FBX users without recent exposure to ALP incurred significantly (p<0.01) less cost than ALP users. Multivariate models also found that both FBX cohorts, with and without recent exposure to ALP, had significantly (p<0.0001) higher gout-specific cost, due almost entirely to higher FBX acquisition cost. However, increased gout-specific expenditure in the FBX cohort without recent ALP exposure was offset by significantly lower CV (p<0.0001) and renal- (p<0.0001) related cost. There were no significant differences, adjusted, in either renal or CV costs between the ALP cohort and FBX patients with baseline exposure to ALP. Similarly, there was no significant difference in DM-related expenses between any of the cohorts.
Conclusion The use of FBX in first- and second-line settings may confound outcome evaluation since FBX use after ALP failure may suggest more aggressive disease. Gout patients with concurrent CKD, initiating on FBX in a first-line setting incurred significantly less total cost than patients initiating on ALP. Higher acquisition cost for treatment with FBX should not be a barrier to appropriate treatment, especially in patients with co-morbid CV and renal conditions.
Disclosure:
G. Mitri,
Takeda Pharmaceuticals International,
3;
E. Wittbrodt,
Takeda Pharmaceuticals International,
3;
R. Turpin,
Takeda Pharmaceuticals International,
3;
B. Tidwell,
Takeda Pharmaceuticals International,
5;
K. Schulman,
Takeda Pharmaceuticals International,
5.
« Back to 2014 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/real-world-cost-comparison-of-urate-lowering-therapies-in-patients-with-gout-and-moderate-to-severe-chronic-kidney-disease/