Cost-Effectiveness of Latanoprost and Timolol Maleate for the Treatment Of

1,2 1 3 LNCLSTUDY CLINICAL Cost-effectiveness of WC Stewart , JA Stewart and MA Mychaskiw latanoprost and timolol maleate for the treatment of glaucoma in Scandinavia and the United Kingdom, using a decision- analytic health economic model

Abstract Sweden 988 985 SEK; Denmark 351 641; and the UK 4751 GBP. Purpose To assess the cost-effectiveness of Conclusions Over 5 years, in the UK timolol latanoprost or timolol in glaucoma treatment is the cost-effective option, whereas in in Norway, Sweden, Denmark (Scandinavia) Scandinavia latanoprost may be the cost- and the United Kingdom (UK). effective alternative to timolol. Methods A Markov model was constructed to Eye (2009) 23, 132–140; doi:10.1038/sj.eye.6702964; perform a cost-effectiveness analysis. Health published online 24 August 2007 states were ‘stable’ and ‘progressed’ glaucoma, and transition probabilities for both primary Keywords: cost; latanoprost; timolol; Markov open-angle and exfoliation glaucoma were derived from the medical literature. Practice 1PRN Pharmaceutical patterns were obtained from surveys completed by 54 ophthalmologists Research Network, LLC, Introduction Charleston, SC, USA geographically dispersed throughout each country. Country specific unit costs were used The most commonly used first-line agents 2 Carolina Eye Institute, for medications, patient visits, diagnostics, worldwide to treat glaucoma are timolol University of South Carolina, and therapeutic procedures. maleate and the F a prostaglandin analogues. Columbia, SC, USA 2 Results Over the life of the model Generally, prostaglandin analogues are believed 3Pfizer Inc., New York, NY, latanoprost was less expensive than timolol by to have the advantage over timolol of being 1 USA 5.3–7.6% (Scandinavia) and 2.1% (UK). more efficacious and more convenient to dose. Following adjustments, therapy in the original However, in Europe timolol is frequently Correspondence: timolol-treated cohort was slightly more prescribed as first-line therapy since, due to the WC Stewart, effective in each country with a difference in availability of generics, it generally is less 1 Southpark Circle, 0.003–0.015 years to progression of glaucoma expensive per bottle than the prostaglandin Suite 110, Charleston, SC 29407, USA existing between latanoprost. This may have analogs. However, other factors exist that might Tel: þ 843 762 6500; resulted from the model design, which increase the cost of timolol therapy long-term. Fax: þ 843 762 7444. reflected that physicians ultimately control Previous studies have shown that latanoprost E-mail: [email protected] most patients’ glaucoma over 5 years by (XalatanTM, Pfizer Inc., New York, NY, USA), adding or changing therapy. The associated the first prostaglandin analogue made available, Received: 24 February 2007 incremental cost-effectiveness ratios for is a more persistent therapy (remaining Accepted in revised form: 1–6 22 July 2007 latanoprost vs timolol generated by the unaltered) compared to timolol. Published online: 24 August Scandinavian and the UK models, Consequently, treatment with timolol more 2007 respectively, were: Norway 351 396 NOK; often may necessitate therapy changes Cost-effectiveness of latanoprost and timolol maleate WC Stewart et al 133

potentially due to side effects or compliance problems.1 were assumed to have early glaucomatous damage In addition, since the prostaglandin analogs are more consistent with being begun on monotherapy. effective in reducing the intraocular pressure, timolol We based our utility weights on different levels of treatment might require the addition of a second glaucoma published by Kobelt16 using 0.84 for mild medication.7 visual loss, 0.72 for advanced (the second progressed Accordingly, both the lower persistency rate and state). Since our model required an intermediate stat