Two-year treatment patterns and costs in glaucoma patients initiating treatment with prostaglandin analogs

OBJECTIVE To determine treatment patterns and costs over a two-year period among new initiators of topical prostaglandin analogs in a managed care population by retrospective cohort analysis of an insurance claims database. METHODS Patients who initiated therapy with a prostaglandin analog between September 2006 and March 2007 were identified. The use of monotherapy and adjunctive therapies were compared by index prostaglandin. Days to initiation of adjunctive therapy and rates of glaucoma surgical procedures were also calculated. Medical costs (antiglaucoma medications and ophthalmic visits) over the two-year period were estimated. RESULTS The analysis identified 5018 patients with at least one prostaglandin analog prescription (bimatoprost, n = 747; latanoprost, n = 1651; benzalkonium chloride (BAK)-free travoprost, n = 203). The majority (51%-54%) had repeat prescriptions. Among those with repeat prescriptions, 52% were female (not significant) and mean age was 64 years (P < 0.01). Rates of adjunctive therapy use varied across groups (bimatoprost 51%, latanoprost 37%, and BAK- free travoprost 35%, P < 0.0001). Median and mean days to initiation of adjunctive therapy were 83 and 140 for bimatoprost, 101 and 181 for latanoprost, and 113 and 221 for BAK- free travoprost. Two-year medical costs were $3147, $2843, and $2557 for patients initiating treatment with bimatoprost, latanoprost, and BAK-free travoprost, respectively. Use of glaucoma surgical procedures across the treatment groups was similar over the two-year period. CONCLUSIONS Over a two-year period, the rate and time to initiation of adjunctive therapy use, as well as medical costs, varied between index prostaglandins. However, the rate of glaucoma surgical interventions did not vary significantly across index medications.