Impact of noncompliance with urate-lowering drug on serum urate and gout-related healthcare costs: administrative claims analysis*

ABSTRACTObjective: To determine the association between allopurinol compliance and serum urate (sUA) level; and examine the association between sUA and gout-related healthcare costs in a large managed care population.Research design and methods: This retrospective administrative claims analysis examined subjects with gout (≥2 medical claims with ICD-9-CM diagnosis code 274.xx or ≥1 claim with a gout diagnosis and ≥1 pharmacy claim for allopurinol, probenecid, colchicine, or sulfinpyrazone) between January 1, 2002 and March 31, 2004. Each subject was observed during 1-year pre-index and 1-year post-index periods.Main outcome measures: Outcomes were allopurinol medication possession ratio (MPR) and compliance (MPR ≥ 0.80), sUA (mg/dL), and gout-related healthcare costs. ‘Post-allopurinol’ sUA was measured during three periods after the first observed allopurinol fill: 30–89 days; 90–149 days; ≥150 days. A baseline sUA on or before the start of the post-index period was also identified. Outcomes were stratif...