Treatment of ocular hypertension: is it cost effective?

PURPOSE OF REVIEW: The review evaluates the past 18-month literature related to cost-effectiveness of treating ocular hypertension (OHT) and give an opinion of the state of research. RECENT FINDINGS: Three studies question the value of intensive monitoring in OHT and glaucoma. One study suggests that implementing Ocular Hypertension Treatment Study - European Glaucoma Prevention Study (OHTS-EGPS) risk prediction in every day practice overestimates the risk of open-angle glaucoma. While two models suggest that treating all intraocular pressures above 21 mmHg would be cost-saving (but disagree on the impact of this strategy on conversion to glaucoma), another study in turn suggests than we could safely reduce medications in almost half of the patients. Two studies suggest that effective early treatment could decrease follow-up costs in OHT and one modeling study suggests that using laser in preference to medication would be cost effective in glaucoma. SUMMARY: The results of this time-limited review are confusing as they challenge many current beliefs to continue to do more than what we are currently doing. We have a huge gap in understating whether we are currently doing the 'right' things in our every day practices.

Cost-effectiveness of monitoring ocular hypertension based on a risk prediction tool.

BACKGROUND/AIMS: To assess the cost-effectiveness of making treatment decisions for patients with ocular hypertension (OHT) based on a risk prediction (RP) tool in the United Kingdom. METHODS: A discrete event simulation model was constructed to compare the cost-effectiveness of an alternative care pathway in which the treatment decision was guided by a validated RP tool in secondary care against decision-making based on the standard care (SC). Individual patient sampling was used. Patients diagnosed with OHT and with an intraocular pressure of 24 mm Hg or over entered the model with a set of predefined individual characteristics related to their risk of conversion to glaucoma. These characteristics were retrieved from electronic medical records (n=5740). Different stages of glaucoma were modelled following conversion to glaucoma. RESULTS: Almost all (99%) patients were treated using the RP strategy, and less than half (47%) of the patients were treated using the SC strategy. The RP strategy produced higher cost but also higher quality-adjusted life years (QALYs) than the SC strategy. The RP strategy was cost-effective compared with the SC strategy in the base-case analysis, with an incremental cost-effectiveness ratio value of £11 522. The RP strategy had a 96% probability of being cost-effective under a £20 000 per QALY threshold. CONCLUSIONS: The use of an RP tool for the management of patients with OHT is likely to be cost-effective. However, the generalisability of the result might be limited due to the high-risk nature of this cohort and the specific RP threshold used in the study.

Direct cost and predictive factors for treatment in patients with ocular hypertension or early, moderate and advanced primary open-angle glaucoma: the CoGIS study in Germany.

BACKGROUND: The main objectives of this analysis were to assess the treatment costs and to identify major cost drivers and factors predicting direct costs in German patients with ocular hypertension (OHT) or primary open-angle glaucoma (POAG). METHODS: This non-interventional cross-sectional study was conducted in two university hospitals and 13 ophthalmology practices in Germany regions (Bavaria, Rhineland-Palatinate, North Rhine-Westphalia, Hamburg and Mecklenburg-Western Pomerania) between May 2009 and January 2010 to assess resource utilisation in patients with OHT (ICD-10: 40.0) or POAG (ICD-10: 40.1) at early, moderate or advanced stages, according to the European Glaucoma Society classification Guidelines. Treatment patterns and direct costs were evaluated retrospectively for 5 years. Resource utilisation data (medication, hospitalisation, outpatient surgery, visits to ophthalmologists) were abstracted from the charts, and unit costs were applied to estimate direct costs per year (in Euros, 2009), calculated from the perspective of the statutory health insurance in Germany (Gesetzliche Krankenversicherung). Factors predicting costs were assessed in multivariate regression analysis. RESULTS: One hundred and fifty-four patients (17.5% OHT, 27.9% early, 22.7% moderate, and 31.8% advanced POAG), on average 67 years old (SD 11) were included in the study. Average total annual direct costs per patient for OHT were 226 (SD 117), for early POAG 423 (SD 647), moderate 493 (SD 385) and advanced POAG 809 (SD 877). Glaucoma-related medications and hospitalisation represented the two major components of direct costs, increasing with the progression of glaucoma. In addition to treatment switches (p = 0.0001), factors predictive of an increase in total direct costs included the number of hospital interventions (p < 0.0001), disease-state changes since the start of treatment (p = 0.05), and current disease state (p = 0.05). CONCLUSIONS: Direct costs of treatment are higher in glaucoma compared to OHT and further increase in more severe glaucoma states. Additional treatment changes are major contributing factors to the increased treatment costs of glaucoma. If intraocular pressure can be controlled over the long term, progression to moderate and advanced states avoided, and patients remain on initial treatments, treatment costs could decline due to reduced and less expensive healthcare resource utilisation.

Protocol for a randomised controlled trial to estimate the effects and costs of a patient centred educational intervention in glaucoma management.

BACKGROUND: Poor glaucoma education is thought to be a causative factor of non-adherence to glaucoma therapy. However, the multi-factorial nature of non-adherent behaviour may explain the failure of purely educational interventions to achieve significant improvement in adherence. Behaviour Change Counselling (BCC) allows both the imparting of information and assessment of patient ambivalence to medication use and may elicit behaviour change in order to achieve better adherence. The chronic and complex nature of glaucoma means that patient non-adherence to glaucoma therapy does not easily correlate with measureable objective clinical endpoints. However, electronic medication monitoring offers an objective method of measuring adherence without reliance on clinical endpoints. METHODS/DESIGN: The study is a randomised controlled trial (RCT) with glaucoma (open angle) or ocular hypertension patients attending a glaucoma clinic and prescribed travoprost. The study will determine whether additional glaucoma education using BCC is beneficial and cost effective in improving adherence with glaucoma therapy. An 8-month follow-up period, using an electronic adherence monitoring device (Travalert dosing aid, TDA), will indicate if the intervention is likely to be sustained in the longer term. Additionally, a cost-effectiveness framework will be used to estimate the cost benefit of improving adherence. The development of a novel intervention to deliver glaucoma education using BCC required practitioner training and fidelity testing. Five practitioners were successfully trained to become Glaucoma Support Assistants able to deliver the BCC intervention. The research group had prior clinical and investigative experience in this setting, and used multiple strategies to design a method to address the study objectives. DISCUSSION: This RCT, using BCC to improve adherence to ocular hypotensive therapy, to our knowledge is the first within this disease area. Using a variety of adherence measures allows examination of the known inaccuracies of patient self-report with respect to glaucoma medication. The novel BCC component has undergone fidelity testing using BECCI and the BCC template will ensure conformity to a standardised intervention. TRIAL REGISTRATION: Current Controlled Trials: ISRCTN89683704.

Modeling complex treatment strategies: construction and validation of a discrete event simulation model for glaucoma.

OBJECTIVE: Discrete event simulation (DES) modeling has several advantages over simpler modeling techniques in health economics, such as increased flexibility and the ability to model complex systems. Nevertheless, these benefits may come at the cost of reduced transparency, which may compromise the model's face validity and credibility. We aimed to produce a transparent report on the construction and validation of a DES model using a recently developed model of ocular hypertension and glaucoma. METHODS: Current evidence of associations between prognostic factors and disease progression in ocular hypertension and glaucoma was translated into DES model elements. The model was extended to simulate treatment decisions and effects. Utility and costs were linked to disease status and treatment, and clinical and health economic outcomes were defined. The model was validated at several levels. The soundness of design and the plausibility of input estimates were evaluated in interdisciplinary meetings (face validity). Individual patients were traced throughout the simulation under a multitude of model settings to debug the model, and the model was run with a variety of extreme scenarios to compare the outcomes with prior expectations (internal validity). Finally, several intermediate (clinical) outcomes of the model were compared with those observed in experimental or observational studies (external validity) and the feasibility of evaluating hypothetical treatment strategies was tested. RESULTS: The model performed well in all validity tests. Analyses of hypothetical treatment strategies took about 30 minutes per cohort and lead to plausible health-economic outcomes. CONCLUSION: There is added value of DES models in complex treatment strategies such as glaucoma. Achieving transparency in model structure and outcomes may require some effort in reporting and validating the model, but it is feasible.

Cost effectiveness of travoprost versus a fixed combination of latanoprost/timolol in patients with ocular hypertension or glaucoma: analysis based on the UK general practitioner research database.

OBJECTIVE: This study aimed to compare the cost effectiveness of travoprost versus a fixed combination of latanoprost/timolol as first-line therapies for ocular hypertension or glaucoma. METHODS: Patient charts were extracted from the UK General Practitioner Research Database. Patients with ocular hypertension or glaucoma who received first-line treatment with either travoprost or latanoprost/timolol and were followed up for >6 months were included. Treatment failure was defined as a treatment change or a glaucoma intervention (laser therapy or surgery). Time to treatment failure was compared using a Cox model and adjusted by the propensity score method. RESULTS: Eligible patients received either travoprost (n=639) or latanoprost/timolol (n=176). Their mean age was 70 years at diagnosis and 48.2% of patients were male. Patient characteristics did not differ significantly between treatment groups. Treatment failure rates at 1 year were 31.3% (travoprost) and 39.4% (latanoprost/timolol) and yielded a hazard ratio for failure in favour of travoprost (0.75; p<0.04) after adjusting for age, sex, co-morbidities and duration of follow-up. Adjusted annual costs of glaucoma management were significantly (p<0.001) less with travoprost (pound215.86) than with latanoprost/timolol (pound327.83). CONCLUSIONS: In everyday practice, travoprost was maintained longer than latanoprost/timolol as first-line therapy for glaucoma. The mean daily costs of travoprost were 50.8% less per patient than those of latanoprost/timolol. Despite adjustments, these results might be confounded, at least partially, by disease severity.

Cost-effectiveness of treating ocular hypertension.

PURPOSE: To assess the cost-effectiveness of treating ocular hypertension (OHT) in the United States. DESIGN: A Markov model was constructed to perform a cost-effectiveness analysis. PARTICIPANTS: Patients with OHT. METHODS: The health states considered were stable OHT and glaucoma. Practice patterns for the model were derived from the Ocular Hypertension Treatment Study (OHTS), and transition probabilities were derived from previous literature. Specific unit costs used for medications, patient visits, and diagnostic and therapeutic procedures were obtained from Blue Cross/Blue Shield. The time horizon was 5 years. Costs were discounted at 3% per annum. MAIN OUTCOME MEASURE: Long-term cost effectiveness of treating OHT to prevent the development of glaucoma. RESULTS: The incremental cost-effectiveness ratio (ICER) for all OHT patients to prevent 1 case from progressing to primary open-angle glaucoma was $89,072. However, the minimally cost-effective ICER level after adjustment for risk factors identified by multivariate analysis in the OHTS were: 20 years above the average of 56 years, ICER of $45,155; 4 mmHg above the average pressure of 25 mmHg, ICER of $46,748; 40 microm less than the average central corneal thickness of 573 mum, ICER of $36,683; and a vertical cup-to-disc ratio of 0.2 wider than the average of 0.4, ICER of $35,633. CONCLUSIONS: Based on the results and practice patterns of the OHTS, treating all OHT patients seems not to be cost-effective. However, treating selective OHT patients with risk factors identified in the OHTS, for example, advancing age, higher pressures, thinner central corneal thickness, and wider vertical cup-to-disc ratios, does seem to be cost-effective for preventing the onset of glaucomatous damage.

The costs of treating glaucoma with combinations of topical drugs in Spain.

PURPOSE: This study describes the treatment in ordinary clinical practice in Spain of patients with glaucoma with a two-drug combination therapy. The authors present the treatment outcome as endof-period intraocular pressure (IOP) and the calculated direct medical costs over a 2-year period. METHODS: Data were extracted retrospectively from patient charts recording the use of all medical resources related to glaucoma. Costs were estimated using unit costs from public sources (2005). Descriptive cost analysis according to combination treatment at baseline was performed. RESULTS: The study included 216 patients from 21 centers. Around half of the patients were started on a beta-blocker/prostaglandin analogue combination, while the rest received various other combinations containing either an alpha2-agonist or a carbonic anhydrase inhibitor. Across the seven groups considered, there was a statistically significant difference in the costs of the least and the two most costly groups, while the confidence intervals were overlapping in all other pairwise comparisons. The least costly drug combination was brimonidine/timolol. Assessing IOP at the end of follow-up, all the groups were equally effective (overlapping confidence intervals). In a multivariate regression analysis, the drug combination did not have an independent, significant impact on total direct medical costs, drug costs, or end-of-period IOP. Significant determinants of these variables were surgical interventions and one or more changes of drug combination during the follow-up. CONCLUSIONS: Costs are determined by the response to treatment. Inadequate response triggers treatment changes and sometimes eventually surgical interventions, thereby increasing costs significantly.

Shared Cared for Stable Glaucoma Patients: Economic Benefits and Patient-centered Outcomes of a Feasibility Trial.

PURPOSE: The purpose of this article is to assess the quality of care and economic benefits of a shared care model managing patients with stable glaucoma in a primary eye care (PEC) clinic compared with a tertiary specialist outpatient clinic (SOC) in Singapore. PATIENTS AND METHODS: A randomized equivalence feasibility trial was preformed comparing the PEC with SOC models. Participants recruited from the SOC had no visual field progression or change in management for at least 3 years, were on a maximum of a single glaucoma medication, had no previous tube-shunt implant and were at least 3-year posttrabeculectomy surgery.Primary outcomes were clinical assessment and management, economic benefits, and patient satisfaction. Differences were analyzed using equivalence testing and generalized odds ratios. RESULTS: The trial included 233 patients, consisting of 42.1% glaucoma disc suspects (PEC: 47.4%; SOC: 36.8%), 27.5% primary angle closure suspects (PEC: 25.0%; SOC: 29.9%), 13.7% with ocular hypertension (PEC: 13.8%; SOC: 13.7%), 3.9% with primary angle closure glaucoma (PEC: 4.3%; SOC: 3.4%), and 3.0% with primary open angle glaucoma (PEC: 1.7%; SOC: 4.3%). Glaucoma clinical care for patients at PEC was as good as SOC [rate difference, 6.83%; 95% confidence interval (CI), 2.84-11.12) and management (rate difference, 7.69%; 95% CI, 3.21-12.17). In 23 cases (9.9%), 5.2% at PEC and 14.5% at SOC, there was disconcordance with the gold standard of senior consultant. Patient satisfaction at the PEC was equally high when compared with SOC (generalized odds ratio, 1.43; CI, 0.50-2.00). Direct costs per patient visit were 43% lower at PEC compared with SOC. CONCLUSION: Managing stable glaucoma patients at a primary care setting is a cost saving, safe, and effective shared care while enhancing professional collaboration between hospital and community settings.

Changing Initial Glaucoma Medical Therapy Increases Healthcare Resource Utilization.

PURPOSE: To determine the frequency and economic impact of changing initial glaucoma therapy for patients with newly diagnosed open-angle glaucoma (OAG) or ocular hypertension (OHT). METHODS: This retrospective longitudinal cohort study identified individuals within a large managed care network in the United States, who were newly diagnosed with OAG or OHT from 2001 to 2012 and were prescribed either a topical beta blocker (BB) or a prostaglandin analog (PGA). Claims data were analyzed over the 12-month period following their index prescription to determine physician prescribing habits, healthcare resource utilization patterns, and sociodemographic factors which may have contributed to changing the initial treatment strategy. RESULTS: A total of 15,019 beneficiaries were identified with newly diagnosed OAG or OHT and whose index therapy was either a topical BB or PGA. Among these enrollees 80.9% were started on PGAs, while 19.1% were started on BBs. Of these beneficiaries, 29.2% of those started on PGAs and 39.5% of those started on BBs underwent a change in therapy within 12 months of their index prescription. Those in the topical BB treatment group had a 38% increased odds of changing glaucoma therapy relative to those started on PGAs (odds ratio [OR] 0.61, 95% CI:0.56-0.68). Patients who changed therapy required more frequent office visits (P < 0.0001) and incurred higher median eye care related charges (P < 0.0001) compared to those who remained on the index therapy unchanged. CONCLUSIONS: Changing initial ocular hypotensive therapy is common. Individuals who undergo a change in therapy required more frequent face-to-face monitoring and incurred higher healthcare related costs. Identifying strategies capable of optimizing the process of initiating ocular hypotensive therapy are appealing and possess the potential to improve patient outcomes and reduce healthcare costs.

A multicenter, retrospective pilot study of resource use and costs associated with severity of disease in glaucoma.

OBJECTIVE: To examine resource consumption and the direct costs of treating glaucoma at different disease severity levels. DESIGN: Observational, retrospective cohort study based on medical record review. PARTICIPANTS: One hundred fifty-one records of patients with primary open-angle or normal-tension glaucoma, glaucoma suspect, or ocular hypertension (age > or =18 years) were randomly selected from 12 sites in the United States and stratified according to severity based on International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patients had to have been followed up for a minimum of 5 years. Patients with concomitant ocular disease likely to affect glaucoma treatment-related resource consumption were excluded. METHODS: Glaucoma severity was assessed and assigned using a 6-stage glaucoma staging system, modified from the Bascom Palmer (Hodapp-Anderson-Parrish) system. Clinical and resource use data were collected from the medical record review. Resource consumption for low-vision care and vision rehabilitation was estimated for patients with end-stage disease based on specialist surveys. For each stage of disease, publicly available economic data were then applied to assign resource valuation and estimate patient-level direct costs from the payer perspective. MAIN OUTCOME MEASURES: Average annual resource use and estimated total annual direct cost of treatment were calculated at the patient level and stratified by stage of disease. Direct costs by specific resource types, including ophthalmology visits, glaucoma surgeries, medications, visual field examinations, and other glaucoma services, were also assessed. RESULTS: Direct ophthalmology-related resource use, including ophthalmology visits, glaucoma surgeries, and medication use, increased as disease severity worsened. Average direct cost of treatment ranged from $623 per patient per year for glaucoma suspects or patients with early-stage disease to $2511 per patient per year for patients with end-stage disease. Medication costs composed the largest proportion of total direct cost for all stages of disease (range, 24%-61%). CONCLUSIONS: The study results suggest that resource use and direct cost of glaucoma management increase with worsening disease severity. Based on these findings, a glaucoma treatment that delays the progression of disease could have the potential to significantly reduce the health economic burden of this chronic disease over many years.

Management of ocular hypertension: a cost-effectiveness approach from the Ocular Hypertension Treatment Study.

PURPOSE: The Ocular Hypertension Treatment Study (OHTS) demonstrated that medical treatment of people with intraocular pressure (IOP) of > or =24 mm Hg reduces the risk of the development of primary open-angle glaucoma (POAG) by 60%. There is no consensus on which people with ocular hypertension would benefit from treatment. DESIGN: Cost-utility analysis with the use of a Markov model. METHODS: We modeled a hypothetic cohort of people with IOP of > or =24 mm Hg. Four treatment thresholds were considered: (1) Treat no one; (2) treat people with a > or =5% annual risk of the development of POAG; (3) treat people with a > or =2% annual risk of the development of POAG, and (4) treat everyone. The incremental cost-effectiveness ratio was evaluated. RESULTS: The incremental cost-effectiveness ratios for treatment of people with ocular hypertension were 3670 US dollars per quality adjusted life-year (QALY) for the Treat > or =5% threshold and 42,430 US dollars/QALY for the Treat > or =2% threshold. "Treat everyone" cost more and was less effective than other options. Assuming a cost-effectiveness threshold of 50,000 to 100,000 US dollars/QALY, the Treat > or =2% threshold would result in the most net health benefit. The decision was sensitive to the incidence of POAG without treatment, treatment effectiveness, and the utility loss because of POAG. CONCLUSION: Although the treatment of individual patients is largely dependent on their attitude toward the risk of disease progression and blindness, the treatment of those patients with IOP of > or =24 mm Hg and a > or =2% annual risk of the development of glaucoma is likely to be cost-effective. Delay of treatment for all people with ocular hypertension until glaucoma-related symptoms are present appears to be unnecessarily conservative.

Cost-effectiveness of monotherapy treatment of glaucoma and ocular hypertension with the lipid class of medications.

PURPOSE: Cost-effectiveness evaluation of monotherapy with the newer lipid class of intraocular pressure (IOP)-lowering medications in glaucoma and ocular hypertension. DESIGN: Retrospective pharmacoeconomic analysis. METHODS: Analysis included all published studies measuring IOP reduction from untreated baseline with once-daily bimatoprost (Lumigan), latanoprost (Xalatan), or travoprost (Travatan) monotherapy in patients with elevated IOP. Percentage IOP reduction at the final study visit was calculated using the early morning IOP measurement to control for diurnal variation in IOP. Patient-weighted average percentage IOP reductions were computed for each medication. Cost per 2.5-ml bottle was determined using PriceAlert 2005 (February). Cost-effectiveness was defined as monthly cost of medication per patient-weighted average 1% reduction in IOP. RESULTS: Studies included 951 bimatoprost, 1598 latanoprost, and 765 travoprost patients. The AWP in February, 2005 for a 2.5-ml bottle was 62.10 dollars for bimatoprost, 61.29 dollars for latanoprost, and 62.19 dollars for travoprost. Patient-weighted average IOP reduction was 32.4% for bimatoprost, 29.6% for latanoprost, and 29.0% for travoprost. Calculated cost-effectiveness was 1.92 dollars for bimatoprost, 2.07 dollars for latanoprost, and 2.14 dollars for travoprost. Incremental cost-effectiveness ratio (ICER) analysis showed an incremental cost of 0.29 dollars for each additional 1% IOP reduction provided by bimatoprost over latanoprost. The rank order of the cost-effectiveness of the drugs (bimatoprost > latanoprost > travoprost) was robust in sensitivity analyses to cost and efficacy. CONCLUSIONS: On the basis of AWP and patient-weighted average percentage IOP reduction in published studies, bimatoprost had the most favorable cost-effectiveness among the drugs compared. Cost-effectiveness should be considered along with traditional clinical safety and efficacy measures to make individual and group healthcare decisions.

Estimated comparative costs of achieving a 20% reduction in intraocular pressure with bimatoprost or latanoprost in patients with glaucoma or ocular hypertension.

BACKGROUND: Although the probability of treatment success should be the primary factor guiding the choice of an intraocular pressure (IOP)-lowering medication, treatment cost is also important to physicians, patients and third-party payers. The objective of the present study was to compare the cost effectiveness of bimatoprost with that of latanoprost in the treatment of glaucoma and ocular hypertension. METHODS: Estimated yearly costs and cost per treatment success for bimatoprost ophthalmic solution 0.03% once daily (Lumigan), Allergan, Inc., Irvine, CA, USA) were compared with those for latanoprost ophthalmic solution 0.005% once daily (Xalatan), Pfizer, Inc., New York, NY, USA). The pharmacoeconomic model was based on medical resource costs and the percentage of patients achieving > or =20% decrease in IOP from baseline at 8:00 am, 12:00 pm and 4:00 pm after 6 months of treatment (clinical success rate). Calculations were also made using the average success rate throughout the day and the average success rate minus the percentage of patients who withdrew from treatment as a result of adverse events. RESULTS: After 6 months of treatment, the clinical success rates were significantly higher with bimatoprost than with latanoprost (p < or = 0.003). The average expected yearly cost per patient was similar for bimatoprost (US1151 dollars) and latanoprost (US1193 dollars). The cost per treatment success, however, averaged US568 dollars less with bimatoprost (US1501 dollars/success) than with latanoprost (US2069 dollars/success). This was true even when the percentage of patients who withdrew from treatment as a result of adverse events was subtracted from the clinical success rate. CONCLUSION: The greater efficacy of bimatoprost resulted in a lower cost per treatment success than was seen with latanoprost. This remained true even when responder rates were adjusted by subtracting the percentage of patients who withdrew from treatment as a result of adverse events.

Bimatoprost: a pharmacoeconomic review of its use in open-angle glaucoma and ocular hypertension.

Bimatoprost (Lumigan) is a prostamide analogue used for the reduction of elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension. In comparative clinical trials of up to 1 year in duration, administration of 0.03% bimatoprost ophthalmic solution once daily was more effective than 0.5% timolol twice daily and at least as effective as the prostaglandin analogues 0.005% latanoprost and 0.004% travoprost once daily in terms of reducing IOP and/or achieving target IOP levels. Bimatoprost was also more effective than twice-daily administration of 0.5%/2% timolol/dorzolamide in patients refractory to topical timolol therapy. Although generally well tolerated, bimatoprost is associated with a higher incidence of conjunctival hyperaemia than latanoprost, timolol or the combination of timolol and dorzolamide. Three fully published modelled cost-effectiveness analyses of bimatoprost evaluating cost per treatment success in patients with glaucoma or ocular hypertension have been conducted in the US. The analyses incorporated results of randomised, multicentre clinical trials and used a 1-year time horizon. In the treatment algorithm used in the models, patients not achieving target IOP levels with bimatoprost or comparator required additional medical visits and adjunctive therapy. Bimatoprost was associated with lower costs per treatment success than latanoprost, timolol or timolol/dorzolamide across a range of clinically relevant target IOPs. Results were sensitive to changes in treatment success rates and/or drug acquisition costs. Along with the inherent limitations of economic models, other possible criticisms of the analyses are the use of selected IOP data, and the lack of inclusion of costs associated with conjunctival hyperaemia or other adverse effects of therapy. Various other cost-effectiveness analyses of bimatoprost are available, primarily as abstracts and/or posters. In general, most of these studies have also been favourable for bimatoprost, despite having been conducted in different countries and/or from different perspectives. In conclusion, in patients with open-angle glaucoma or ocular hypertension, bimatoprost is an effective and generally well tolerated therapeutic option, albeit with a relatively high incidence of conjunctival hyperaemia. Although results of modelled cost-effectiveness analyses should be interpreted with due consideration of the limitations of the studies, available pharmacoeconomic data generally support the use of bimatoprost as a cost-effective treatment in this patient population.

Considerations in developing model-based economic evaluations of glaucoma treatment.

PURPOSE: To facilitate future glaucoma model development and to provide guidance for decision-makers evaluating them, we provide an overview of an innovative glaucoma model and highlight important modeling considerations. CONSIDERATIONS: The considerations that were addressed include: disease outcome that is both relevant and meaningful to current clinical practice; diversity in treatment options and practices; incorporation of therapy discontinuation; and consideration of the variability in patient response to treatment. MODEL SCOPE: A state-transition, Monte Carlo simulation model was developed to simulate the management and treatment of patients with glaucoma and/or ocular hypertension. The model examines strategies involving sequential use of up to 6 pharmacologic interventions. Transitions are based on the monthly probability that a patient is no longer "successfully maintained" on therapy, which can be a consequence of lack of intraocular pressure control, adverse events, lack of compliance, or lack of persistence. Outputs of the model include months on each treatment, frequency of therapy switches, days of intraocular pressure control, frequency of ophthalmologist visits, frequency of surgery, and glaucoma-related costs. The model allows the user to specify country-specific treatment strategies, survival on therapy, surgical rates, practice patterns, and costs. CONCEPT APPLICATION: The model presented offers insights into accommodating patient and clinician variability through the use of persistence distributions. It will facilitate future glaucoma model development and provide insight for decision-makers who must evaluate model-based analyses of the economic value of glaucoma interventions.

Resource use and costs for a glaucoma screening program in Austria: an 8-year review: a cost-consequence analysis based on the Salzburg-Moorfields Collaborative Glaucoma Study.

PURPOSE: The aim of this study is to report costs, detection rates, and resources needed for detection of primary open angle glaucoma and related diseases in a glaucoma screening program in Salzburg, Austria, over a period of 8 years. METHODS: The Salzburg-Moorfields Collaborative Glaucoma Study performed a complete ophthalmologic examination on a total of 4864 subjects within a study period of approximately 8 years (98 months). The total numbers reported are total number of subjects screened at the initial examination and follow-up examinations; total working hours and estimated working hours per visit for one ophthalmologist and two medical assistants; direct costs per visit; detection rates for subjects; and corresponding costs per true positive case diagnosed with definite primary open angle glaucoma (POAG), early POAG, POAG suspect, ocular hypertension (OHT), and glaucoma artefact. RESULTS: Within the screening period of 98 months, a total of 9427 examinations and second verification checks were performed: 5466 at the initial examination, 404 at the 1-year follow-up, 815 at the 2-year follow-up, 339 at the 3-year follow-up, 225 at the 4-year follow-up, 1059 at the 5-year follow-up, 996 at the 6-year follow-up, 118 at the 7-year follow-up, and 5 at the 8-year follow-up. The total amount of time spent for screening was 23,814 working hours. We estimate the costs per visit at EUR 123 for each initial examination, EUR 28 for each second confirmation check, and EUR 95 per follow-up examination. The following detection rates were observed: definite POAG: 1.7% (95% CI: 1.3-2.2%), early POAG: 2.9% (95% CI: 2.3-3.5%), POAG suspect: 8.5% (95% CI: 7.6-9.4%), OHT: 2.2% (95% CI: 1.7-2.7%), glaucoma artefact or other causes: 5.8% (95% CI: 5.1-6.6%), normal cases: 79% (95% CI: 78-80%). CONCLUSIONS: Direct costs per visit were considerably higher than those reported in the Netherlands or the United Kingdom. If a health care provider decides to perform a glaucoma screening within this setting, the costs for the detection of a new case are EUR 7250 for definite POAG, EUR 4250 for early POAG, EUR 1450 for POAG suspect, EUR 5600 for OHT, EUR 2100 for glaucoma artefact case, and EUR 156 for a normal case.

Monitoring ocular hypertension, how much and how often? A cost-effectiveness perspective.

OBJECTIVE: To assess the efficiency of alternative monitoring services for people with ocular hypertension (OHT), a glaucoma risk factor. DESIGN: Discrete event simulation model comparing five alternative care pathways: treatment at OHT diagnosis with minimal monitoring; biennial monitoring (primary and secondary care) with treatment if baseline predicted 5-year glaucoma risk is ≥6%; monitoring and treatment aligned to National Institute for Health and Care Excellence (NICE) glaucoma guidance (conservative and intensive). SETTING: UK health services perspective. PARTICIPANTS: Simulated cohort of 10 000 adults with OHT (mean intraocular pressure (IOP) 24.9 mm Hg (SD 2.4). MAIN OUTCOME MEASURES: Costs, glaucoma detected, quality-adjusted life years (QALYs). RESULTS: Treating at diagnosis was the least costly and least effective in avoiding glaucoma and progression. Intensive monitoring following NICE guidance was the most costly and effective. However, considering a wider cost-utility perspective, biennial monitoring was less costly and provided more QALYs than NICE pathways, but was unlikely to be cost-effective compared with treating at diagnosis (£86 717 per additional QALY gained). The findings were robust to risk thresholds for initiating monitoring but were sensitive to treatment threshold, National Health Service costs and treatment adherence. CONCLUSIONS: For confirmed OHT, glaucoma monitoring more frequently than every 2 years is unlikely to be efficient. Primary treatment and minimal monitoring (assessing treatment responsiveness (IOP)) could be considered; however, further data to refine glaucoma risk prediction models and value patient preferences for treatment are needed. Consideration to innovative and affordable service redesign focused on treatment responsiveness rather than more glaucoma testing is recommended.

Variation in Number of Doses, Bottle Volume, and Calculated Yearly Cost of Generic and Branded Latanoprost for Glaucoma.

PURPOSE: To evaluate discrepancies in doses per bottle, bottle fill volume, and cost among branded and generic formulations of latanoprost. DESIGN: Comparative economic analysis. METHODS: This study was conducted at the Ruiz Department of Ophthalmology and Visual Science at The University of Texas Health Science Center at Houston (UTHealth). Four regionally available latanoprost formulations were measured. Number of drops per bottle and actual bottle fill volume were measured for a calculated sample size (10 bottles). Annual cost (using average wholesale price), days use per bottle, drops per milliliter, and number of bottles used per year were calculated. Data were summarized using mean and standard deviation; 1-way analysis of variance and post hoc Tukey's studentized range test were used for comparing means among manufacturers. RESULTS: Pfizer's branded lantanoprost, Xalatan (New York, New York, USA), had the largest fill volume (P < .001). Pfizer had the highest yearly cost at $1198 (P < .001), whereas Akorn (Lake Forest, Illinois, USA) and Bausch & Lomb (Rochester, New York, USA) had the lowest ($184 and $201, respectively). Pfizer and Bausch & Lomb had the most drops per bottle (87.3 and 88.7, respectively), which was statistically more (P < .001) than either Akorn or Sandoz (Princeton, New Jersey, USA) (77.6 and 76.6, respectively), but there was no statistical difference among the standard deviation of drops per bottle (Levene 0.14). CONCLUSIONS: Annual cost and number of doses per bottle, factors important to patients, vary significantly depending on the manufacturer of latanoprost. Practitioners can better advise patients by being aware of these differences.

The economic burden of glaucoma and ocular hypertension: implications for patient management: a review.

This paper reviews the burden and economic consequences of glaucoma upon healthcare systems and patients, especially elderly patients. An extensive review of the literature was conducted, primarily using MEDLINE, but also by examining selected article reference lists, relevant websites and the proceedings of specialised conferences. All relevant articles and documents were analysed. Glaucoma is characterised by destruction of the optic nerve. It is most often a continuous, chronic eye disease and the most frequent diagnosis is primary open angle glaucoma (POAG). POAG is mostly associated with intraocular hypertension which can be delayed by medication, surgery or laser therapy. The prevalence rate of glaucoma is about 1% in the population >50 years of age. The rate increases with age and is higher in Black and Hispanic populations. Glaucoma affects more than 67 million people worldwide. Cost-of-illness studies have shown the importance of this disease, on which more than pound300 million was spent in the UK in 2002. Most of the costs (45%) were associated with direct medical costs, but direct nonmedical costs (20%) and indirect costs (35%) were also not negligible. Recent economic studies have shown a dramatic increase in the number of patients with glaucoma receiving treatment but a reduction in use of surgical procedures to treat the condition, especially as first-line therapy. The greater part of medical expenditure is now on medication, with new, more potent, better tolerated, but more costly drugs replacing older and less expensive medications. Treatment costs are directly related to the severity of disease and the number of different treatments used; they are also negatively correlated with treatment efficacy in reducing intraocular pressure. However, long-term economic benefits that may be associated with use of more potent new drugs (by delaying institutionalisation) have never been documented. Glaucoma screening has also been found not to be cost effective, although these results should be reconsidered in the light of new data.