CME review: A cost-utility analysis of laser photocoagulation for extrafoveal choroidal neovascularization

A systematic review on the quality, validity and usefulness of current cost-effectiveness studies for treatments of neovascular age-related macular degeneration

PURPOSE

Ophthalmologists increasingly depend on new drugs to advance their treatment options. These options are limited by restraints on reimbursements for new and expensive drugs. These restraints are put in place through health policy decisions based on cost-effectiveness analyses (CEA). Cost-effectiveness analyses need to be valid and of good quality to support correct decisions to create new treatment opportunities. In this study, we report the quality, validity and usefulness of CEAs for therapies for nAMD.

METHODS

A systematic review in PubMed, EMBASE and Cochrane was performed to include CEAs. Quality and validity assessment was based on current general quality criteria and on elements that are specific to the field of ophthalmology.

RESULTS

Forty-eight CEAs were included in the review. Forty-four CEAs did not meet four basic model quality and validity criteria specific to CEAs in the field of ophthalmology (both eyes analysed instead of one; a time horizon extending beyond 4 years; extrapolating VA and treatment intervals beyond trial data realistically; and including the costs of low-vision). Four CEAs aligned with the quality and validity criteria. In two of these CEAs bevacizumab as-needed (PRN) was more cost-effective than bevacizumab monthly; aflibercept (VIEW); or ranibizumab monthly or PRN. In two CEAs, ranibizumab (PRN or treat and extent) was dominant over aflibercept. In two other CEAs, aflibercept was either more cost-effective or dominant over ranibizumab monthly or PRN.

CONCLUSION

Two of the CEAs of sufficient quality and validity show that bevacizumab PRN is the most cost-effective treatment. Comparing ranibizumab and aflibercept, either treatment can be more cost-effective depending on the assumptions used for drug prices and treatment frequencies. The majority of the published CEAs are of insufficient quality and validity. They wrongly inform decision-makers at the cost of opportunities for ophthalmologists to treat patients. As such, they may negatively influence overall patient outcomes and societal costs. For future ophthalmic treatments, CEAs need to be improved and only published when they are of sufficient quality and validity.

Health State Utility Values for Age-Related Macular Degeneration: Review and Advice

Health state utility values are a major source of uncertainty in economic evaluations of interventions for age-related macular degeneration (AMD). This review identifies and critiques published utility values and methods for eliciting de novo utility values in AMD. We describe how utility values have been used in healthcare decision making and provide guidance on the choice of utility values for future economic evaluations for AMD. Literature was searched using PubMed, and health technology assessments (HTA) were searched using HTA agency websites to identify articles reporting utility values or approaches to derive utility values in AMD and articles applying utilities for use in healthcare decision making relating to treatments for AMD. A total of 70 studies qualified for data extraction, 22 of which were classified as containing utility values and/or elicitation methods, and 48 were classified as using utility values in decision making. A large number of studies have elicited utility values for AMD, although those applied to decision making have focused on a few of these. There is an appreciation of the challenges in the measurement and valuation of health states, with recent studies addressing challenges such as the insensitivity of generic health-related quality of life (HRQoL) questionnaires and utility in the worse-seeing eye. We would encourage careful consideration when choosing utility values in decision making and an explicit critique of their applicability to the decision problem.

SOCIETAL COSTS ASSOCIATED WITH NEOVASCULAR AGE-RELATED MACULAR DEGENERATION IN THE UNITED STATES

PURPOSE

The purpose of this study was to use a cross-sectional prevalence-based health care economic survey to ascertain the annual, incremental, societal ophthalmic costs associated with neovascular age-related macular degeneration.

METHODS

Consecutive patients (n = 200) with neovascular age-related macular degeneration were studied. A Control Cohort included patients with good (20/20-20/25) vision, while Study Cohort vision levels included Subcohort 1: 20/30 to 20/50, Subcohort 2: 20/60 to 20/100, Subcohort 3: 20/200 to 20/400, and Subcohort 4: 20/800 to no light perception. An interviewer-administered, standardized, written survey assessed 1) direct ophthalmic medical, 2) direct nonophthalmic medical, 3) direct nonmedical, and 4) indirect medical costs accrued due solely to neovascular age-related macular degeneration.

RESULTS

The mean annual societal cost for the Control Cohort was $6,116 and for the Study Cohort averaged $39,910 (P < 0.001). Study Subcohort 1 costs averaged $20,339, while Subcohort 4 costs averaged $82,984. Direct ophthalmic medical costs comprised 17.9% of Study Cohort societal ophthalmic costs, versus 74.1% of Control Cohort societal ophthalmic costs (P < 0.001) and 10.4% of 20/800 to no light perception subcohort costs. Direct nonmedical costs, primarily caregiver, comprised 67.1% of Study Cohort societal ophthalmic costs, versus 21.3% ($1,302/$6,116) of Control Cohort costs (P < 0.001) and 74.1% of 20/800 to no light perception subcohort costs.

CONCLUSION

Total societal ophthalmic costs associated with neovascular age-related macular degeneration dramatically increase as vision in the better-seeing eye decreases.

Cost-Effectiveness Models in Age-Related Macular Degeneration: Issues and Challenges

Age-related macular degeneration (AMD) is a common ophthalmic condition that can have few symptoms in its early stage but can progress to major visual impairment. While there are no treatments for early-stage AMD, there are multiple modalities of treatment for advanced disease. Given the increasing prevalence of the disease, there are dozens of analyses of cost effectiveness of AMD treatments, but methods and approaches vary broadly. The goal of this review was to identify, characterize, and critique published models in AMD and provide guidance for their interpretation. After a literature review was performed to identify studies, and exclusion criteria applied to limit the review to studies comparing treatments for AMD, we compared methods across the 36 studies meeting the review criteria. To some extent, variation was related to targeting different audiences or acknowledging the most appropriate population for a given treatment. However, the review identified potential areas of uncertainty and difficulty in interpretation, particularly regarding duration of observation periods and the importance of visual acuity as an endpoint or a proxy for patient-reported utilities. We urge thoughtful consideration of these study characteristics when comparing results.

The cost-utility of aflibercept for the treatment of age-related macular degeneration compared to bevacizumab and ranibizumab and the influence of model parameters

BACKGROUND

Age-related macular degeneration (AMD) is a blinding disease placing considerable burden on society due to blindness-associated costs. Intravitreal anti-vascular endothelial growth factors (anti-VEGFs) are effective in reducing the incidence of blindness, but at potentially high costs, depending on the cost of the drug used. Aflibercept has been introduced as an anti-VEGF equally effective to ranibizumab, but less costly. For this new drug, new cost-effectiveness analyses are needed, and AMD models used today give biased results. We investigated the cost-effectiveness of aflibercept compared to bevacizumab, ranibizumab, and no treatment and studied the influence of commonly used model parameters.

METHODS

A patient-level, visual acuity-based, 2-eye model was developed. Data on effectiveness were derived from randomized controlled trials evaluating the outcomes of aflibercept, bevacizumab, and ranibizumab. Utility and resource utilization were assessed in interviews with AMD patients. Costs were based on standard health care cost prices. Time horizons were two and five years. A societal perspective was employed.

RESULTS

Over five years, costs associated with aflibercept treatment were <euro>36,030, with 2.15 QALYs. Costs associated with the bevacizumab regimens, ABC study as-needed (PRN); CATT study PRN; and CATT study 1×/month, were <euro>19,367; <euro>26,746; and <euro>30,520, with 2.16; 2.17; and 2.15 QALYs, respectively. Costs associated with ranibizumab PRN and 1×/month were <euro>45,491 and <euro>74,837 with 2.16 and 2.15 QALYs, respectively. 'No treatment' was associated with <euro>9530 and 1.96 QALYs. The incremental cost-effectiveness ratios versus 'no treatment' were: aflibercept-<euro>140,274; bevacizumab-<euro>51,062 (ABC PRN), <euro>83,256 (CATT PRN) and <euro>110,361 (1×/month); ranibizumab-<euro>181,667 (PRN) and <euro>349,773 (1×/month). Results were highly dependent on whether only one or both eyes were included, length of time horizon, and whether the costs of blindness and low-vision were included in the analysis.

CONCLUSIONS

Aflibercept is a cost-effective treatment for AMD over ranibizumab. However, aflibercept is not a cost-effective treatment when compared to bevacizumab. Application of inappropriate model assumptions leads to a biased cost-saving estimate of the cost-effectiveness of aflibercept. Therefore, cost-effectiveness analyses should be conducted with appropriate models.

Cost-effectiveness of bevacizumab and ranibizumab for newly diagnosed neovascular macular degeneration

PURPOSE

We sought to determine the most cost-effective treatment for patients with newly diagnosed neovascular macular degeneration: monthly or as-needed bevacizumab injections, or monthly or as-needed ranibizumab injections.

DESIGN

Cost-effectiveness analysis.

PARTICIPANTS

Hypothetical cohort of 80-year-old patients with newly diagnosed neovascular macular degeneration.

METHODS

Using a mathematical model with a 20-year time horizon, we compared the incremental cost-effectiveness of treating a hypothetical cohort of 80-year-old patients with newly diagnosed neovascular macular degeneration using monthly bevacizumab, as-needed bevacizumab, monthly ranibizumab, or as-needed ranibizumab. Data came from the Comparison of Age-related macular degeneration Treatment Trial (CATT), the Medicare Fee Schedule, and the medical literature.

MAIN OUTCOME MEASURES

Costs, quality-adjusted life-years (QALYs), and incremental costs per QALY gained.

RESULTS

Compared with as-needed bevacizumab, the incremental cost-effectiveness ratio of monthly bevacizumab is $24,2 357/QALY. Monthly ranibizumab gains an additional 0.02 QALYs versus monthly bevacizumab at an incremental cost-effectiveness ratio of >$10 million/QALY. As-needed ranibizumab was dominated by monthly bevacizumab, meaning it was more costly and less effective. In sensitivity analyses assuming a willingness to pay of $100,000/QALY, the annual risk of serious vascular events would have to be ≥2.5 times higher with bevacizumab than that observed in the CATT trial for as-needed ranibizumab to have an incremental cost-effectiveness ratio of <$100,000/QALY. In another sensitivity analysis, even if every patient receiving bevacizumab experienced declining vision by 1 category (e.g., from 20/25-20/40 to 20/50-20/80) after 2 years but every patient receiving ranibizumab retained their vision level, as-needed ranibizumab would have an incremental cost-effectiveness ratio of $97,340/QALY.

CONCLUSIONS

Even after considering the potential for differences in risks of serious adverse events and therapeutic effectiveness, bevacizumab confers considerably greater value than ranibizumab for the treatment of neovascular macular degeneration.

Epidemiology of major eye diseases leading to blindness in Europe: a literature review

The objective of this work was to study the epidemiology of major eye diseases leading to blindness in Europe through a systematic literature review. The literature search was performed using the Medline database (PubMed), with MeSH and free text search terms. Inclusion criteria for the studies were: (a) performed on a healthy population of Caucasian origin aged between 50 and 75 years; (b) diagnosed by ophthalmological examination in accordance with the International Classification of Diseases 10; (c) contained a detailed description of the sampling and diagnostic procedures and data resources; (d) sample size>500, and (e) published between 1990 and 2008. The results of 57 studies on the prevalence and incidence of age-related macular degeneration, diabetic retinopathy and glaucoma are reported, providing an up-to-date and comprehensive overview of these diseases in Europe from an epidemiological perspective.

Cost effectiveness of treatments for wet age-related macular degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness in people aged ≥50 years. Wet AMD in particular has a major impact on patient quality of life and imposes substantial burdens on healthcare systems. This systematic review examined the cost-effectiveness data for current therapeutic options for wet AMD. PubMed and EMBASE databases were searched for all articles reporting original cost-effectiveness analyses of wet AMD treatments. The Centre for Reviews and Dissemination and Cochrane Library databases were searched for all wet AMD health technology assessments (HTAs). Overall, 44 publications were evaluated in full and included in this review. A broad range of cost-effectiveness analyses were identified for the most commonly used therapies for wet AMD (pegaptanib, ranibizumab and photodynamic therapy [PDT] with verteporfin). Three studies evaluated the cost effectiveness of bevacizumab in wet AMD. A small number of analyses of other treatments, such as laser photocoagulation and antioxidant vitamins, were also found. Ranibizumab was consistently shown to be cost effective for wet AMD in comparison with all the approved wet AMD therapies (four of the five studies identified showed ranibizumab was cost effective vs usual care, PDT or pegaptanib); however, there was considerable variation in the methodology for cost-effectiveness modelling between studies. Findings from the HTAs supported those from the PubMed and EMBASE searches; of the seven HTAs that included ranibizumab, six (including HTAs for Australia, Canada and the UK) concluded that ranibizumab was cost effective for the treatment of wet AMD; most compared ranibizumab with PDT and/or pegaptanib. By contrast, HTAs at best generally recommended pegaptanib or PDT for restricted use in subsets of patients with wet AMD. In the literature analyses, pegaptanib was found to be cost effective versus usual/best supportive care (including PDT) or no treatment in one of five studies; the other four studies found pegaptanib was of borderline cost effectiveness depending on the stage of disease and time horizon. PDT was shown to be cost effective versus usual/best supportive care or no treatment in five of nine studies; two studies showed that PDT was of borderline cost effectiveness depending on baseline visual acuity, and two showed that PDT was not cost effective. We identified no robust studies that properly evaluated the cost effectiveness of bevacizumab in wet AMD.

Cost-effectiveness of ranibizumab for the treatment of neovascular age-related macular degeneration in Germany: Model analysis from the perspective of Germany's statutory health insurance system

BACKGROUND

In clinical trials, ranibizumab has been associated with stabilization and even improvement of visual acuity among patients with neovascular age related macular degeneration (AMD), but its use is also associated with considerable costs.

OBJECTIVE

The aim of this work was to compare ranibizumab with best supportive care or photodynamic therapy (PDT) for AMD by means of economic cost-utility and cost-effectiveness analysis from the perspective of Germany's Statutory Health Insurance System.

METHODS

Visual acuity data from the Anti-VEGF (vascular endothelial growth factor) Antibody for the Treatment of Predominantly Classic Choroidal Neovascularization in AMD (ANCHOR) and Minimally Classic/Occult Trial of the Anti-VEGF Antibody Ranibizumab in the Treatment of Neovascular AMD (MARINA) studies were applied, based on a ranibizumab dose of 0.5 mg. A Markov model simulated visual acuity and costs over 10 years (discounted at 3%). The base-case analysis assumed 5 injections per year over 2 years. Treatment costs were based on year-2008 euros (using German prices) and recommendations for procedure reimbursement from a public health insurance perspective. To assess cost-effectiveness, costs per year of legal blindness avoided (ie, vision-year gained [VYG]) and per quality-adjusted life-year (QALY) were calculated. The model assumed each patient's affected eye had better sight than the other eye, and the 2 comparators against which ranibizumab treatment was assessed were best supportive care and PDT. The robustness of the results was investigated in a univariate sensitivity analysis of all relevant parameters and a multivariate probabilistic sensitivity analysis. The multivariate 95% CIs for incremental cost-effectiveness ratios were obtained by conducting 1000 Monte Carlo simulations.

RESULTS

Compared with best supportive care, costs per VYG for ranibizumab were euro6767 in occult choroidal neovascularization (CNV) and euro6020 in minimally classic CNV. In classic CNV, costs were euro5734/VYG for ranibizumab compared with supportive care and euro778/VYG for ranibizumab compared with PDT. Costs per QALY for ranibizumab treatment for occult, minimally classic CNV, and classic CNV were euro22,320, euro22,538, and euro25,036, respectively, and euro3294 for classic CNV compared with PDT. Results were sensitive to the cost of blindness, injection frequency, and duration. The multivariate 95% CIs for the incremental cost effectiveness ratios were euro14,438 to euro41,110/QALY for occult CNV, euro13,463 to euro43,614/QALY for minimally classic CNV, and euro15,634 to euro51,106/QALY for classic CNV.

CONCLUSION

In this model analysis using costs and clinical trial data from Germany, ranibizumab appeared to be a cost-effective treatment option for all angiographic subtypes of neovascular AMD, from the perspective of Germany's Statutory Health Insurance System.

The quality of pharmacoeconomic evaluations of age-related macular degeneration therapeutics: a systematic review and quantitative appraisal of the evidence

AIM

To appraise the quality of published pharmacoeconomic studies of therapeutic interventions for age-related macular degeneration (AMD).

METHODS

Systematic review of the literature and evaluation of study quality using the Quality of Health Economic Studies instrument. A systematic search of the English-language literature for economic studies of therapeutic interventions for AMD from 1990 to March 2008 was performed.

RESULTS

A total of 3637 articles were initially identified. Only 24 met eligibility criteria and were rated using the Quality of Health Economic Studies. The mean quality overall rating was 61.6, with quality scores ranging from 18 to 92. There was a higher mean quality score in the studies designed as clinical trials versus observational type designed studies (mean=74.7(11.4), 52.6 (16.5) respectively, p=0.002) and studies in which the statistical analyses were clearly presented versus studies in which the statistical analyses were not so clear (mean=74.3 (12.3), 53.1 (16.1) respectively, p=0.004). Interestingly, government funded studies exhibited a similar mean quality score to studies that were funded by industry (mean=71.0 (15.1), 61.7 (18.5) respectively, p=0.25). A general linear model was fitted using those independent variables which were significantly associated with quality score. The variables 'study design' and 'statistics presented clearly' were found to be jointly significant and explained nearly 70% of the variation in the dependent variable (R(2)=0.68).

CONCLUSIONS

Our analysis reveals that the methodological quality of the health economic analysis of AMD therapeutic interventions in the literature is suboptimal. There is considerable variation in methodological rigour between the articles, and we have identified several attributes that are predictive of study quality.

The quality of pharmacoeconomic evaluations of age-related macular degeneration therapeutics: a systematic review and quantitative appraisal of the evidence

AIM

To appraise the quality of published pharmacoeconomic studies of therapeutic interventions for age-related macular degeneration (AMD).

METHODS

Systematic review of the literature and evaluation of study quality using the Quality of Health Economic Studies instrument. A systematic search of the English-language literature for economic studies of therapeutic interventions for AMD from 1990 to March 2008 was performed.

RESULTS

A total of 3637 articles were initially identified. Only 24 met eligibility criteria and were rated using the Quality of Health Economic Studies. The mean quality overall rating was 61.6, with quality scores ranging from 18 to 92. There was a higher mean quality score in the studies designed as clinical trials versus observational type designed studies (mean=74.7(11.4), 52.6 (16.5) respectively, p=0.002) and studies in which the statistical analyses were clearly presented versus studies in which the statistical analyses were not so clear (mean=74.3 (12.3), 53.1 (16.1) respectively, p=0.004). Interestingly, government funded studies exhibited a similar mean quality score to studies that were funded by industry (mean=71.0 (15.1), 61.7 (18.5) respectively, p=0.25). A general linear model was fitted using those independent variables which were significantly associated with quality score. The variables 'study design' and 'statistics presented clearly' were found to be jointly significant and explained nearly 70% of the variation in the dependent variable (R(2)=0.68).

CONCLUSIONS

Our analysis reveals that the methodological quality of the health economic analysis of AMD therapeutic interventions in the literature is suboptimal. There is considerable variation in methodological rigour between the articles, and we have identified several attributes that are predictive of study quality.

A Hybrid Cohort Individual Sampling Natural History Model of Age-Related Macular Degeneration: Assessing the Cost-Effectiveness of Screening Using Probabilistic Calibration

Background. Age-related macular degeneration (AMD) is a leading cause of visual impairment and blindness. It is likely that treatment of AMD at earlier stages is more effective than later treatment; thus, screening for AMD should be considered. The aim of this study was to develop a natural history model of AMD to estimate the cost-effectiveness of screening. Methods. A hybrid cohort/individual sampling decision analytic model was developed. Primary data sets, expert elicitation, and data from the literature were used to populate the model. To incorporate joint parameter uncertainty, and to populate unobservable parameters, an innovative form of probabilistic calibration was applied to a range of output parameters. Results. In the reference case, annual screening from age 60 y is the most cost-effective option, although this is subject to high levels of uncertainty. Alternative, age-specific utility values show that screening is predicted to be less cost-effective, assuming interventions that reduce progression to wet AMD moderately improve the cost-effectiveness of screening, whereas the addition of anti—vascular endothelial growth factor therapy for juxtafoveal or subfoveal wet AMD lesions improves the cost-effectiveness of screening significantly. Conclusions. The extent of the uncertainty around the mean results, and the additional resources and possible reorganization of services required to implement screening, indicate that it may be preferable to reduce the level of uncertainty before implementing screening for AMD. Initial actions may be best targeted at assessing how routine data may be used to describe clinical presentation, a screening pilot study, and a secondary costing study.

An introduction to decision analysis in the economic evaluation of the prevention and treatment of vision-related diseases

Economic evaluation in the form of reports of cost-effectiveness of the treatment and prevention of disease has only recently found widespread application in the visual sciences. While economic evaluation takes a number of forms: cost-minimization analysis, cost-benefit analysis, and cost-effectiveness analysis--it is the latter that is seen most often in the evaluation of vision-related health programs. Cost-effectiveness analysis is in particular seen most commonly in its very particular form of cost-utility analysis. Decision analysis is the analytic method most commonly used to perform cost-effectiveness analysis. In decision analysis, the expected cost and effectiveness of a health program are estimated in a rigorous fashion. In this report, we take the reader through the process of decision analysis including building the tree; populating the model with parameters for risk, cost and benefit; estimating expected cost and benefit; and deterministic and probabilistic sensitivity analysis. Examples employed include prominent studies of the cost-effectiveness of photodynamic therapy for treatment of neovascular macular degeneration and the treatment ocular hypertension to prevent glaucoma.

Laser photocoagulation for neovascular age-related macular degeneration

BACKGROUND

Laser photocoagulation was the first treatment introduced to try to halt the progression of neovascular age-related macular degeneration (AMD), in which newly formed vessels or choroidal neovascularisation (CNV) grow under the macula leading to the occurrence of a scotoma or blind spot in the central visual field.

OBJECTIVES

The aim of this review was to examine the effects of laser photocoagulation for neovascular AMD.

SEARCH STRATEGY

We searched the CENTRAL, MEDLINE, EMBASE, LILACS, NRR and ZETOC in March 2007.

SELECTION CRITERIA

We included randomised trials of laser photocoagulation in people with CNV due to AMD.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data. The risk ratio (RR) of severe visual loss (loss of six or more lines of visual acuity) was estimated at three months and two years after treatment.

MAIN RESULTS

Fifteen trials were included in the review (2064 participants). Three types of photocoagulation were used in the trials: direct photocoagulation of the entire CNV (11 trials), perifoveal photocoagulation (one trial) and grid photocoagulation (three trials). In 12 trials the control group was observation only. One trial compared photocoagulation to submacular surgery and two trials compared different lasers. Data on the progression of visual loss could be extracted from five of the eight trials of direct photocoagulation of the CNV versus observation. The treatment effect was in the direction of harm in all studies at three months follow up (RR 1.41, 95% confidence intervals (CI) 1.08 to 1.82). After two years the treatment effect was in the direction of benefit (RR 0.67, 95% CI 0.53 to 0.83). These studies were clinically heterogeneous with participants having CNV lesions in different locations and different baseline visual acuities. There was little evidence of statistical heterogeneity at three months but substantial statistical heterogeneity at two years. However, all treatment effects in the individual trials were in the direction of benefit. One study comparing perifoveal photocoagulation or observation of subfoveal CNV found benefits that were statistically significant only at two years (RR 0.36, 95% CI 0.18 to 0.72). Other comparisons did not demonstrate differences.

AUTHORS' CONCLUSIONS

In the medium to long term laser photocoagulation of CNV slows the progression of visual loss in people with neovascular AMD. However, it is associated with an increased risk of visual loss immediately after treatment and this period may be longer in people with subfoveal AMD. With the advent of modern pharmacological therapies, and concern for the impact of iatrogenic scotoma in subfoveal CNV, laser photocoagulation of subfoveal CNV is not recommended. No studies have compared photocoagulation with modern pharmacological agents for AMD for non-subfoveal CNV.

Value-based medicine and interventions for macular degeneration

PURPOSE OF REVIEW

The aim of this article is to review the patient value conferred by interventions for neovascular macular degeneration.

RECENT FINDINGS

Value-based medicine is the practice of medicine based upon the patient value (improvement in quality of life and length of life) conferred by an intervention. For ophthalmologic interventions, in which length-of-life is generally unaffected, the value gain is equivalent to the improvement in quality of life. Photodynamic therapy delivers a value gain (improvement in quality of life) of 8.1% for the average person with classic subfoveal choroidal neovascularization, while laser photocoagulation for the same entity confers a 4.4% improvement in quality of life. Preliminary data suggest the value gain for the treatment of occult/minimally classic choroidal neovascularization with ranibizumab is greater than 15%. The average value gain for statins for the treatment of hyperlipidemia is 3.9%, while that for the use of biphosphonates for the treatment of osteoporosis is 1.1% and that for drugs to treat benign prostatic hyperplasia is 1-2%.

SUMMARY

Interventions, especially ranibizumab therapy, for neovascular macular degeneration appear to deliver an extraordinary degree of value compared with many other interventions across healthcare.

Cost-effectiveness of vitamin therapy for age-related macular degeneration

OBJECTIVE

To determine the cost-effectiveness of vitamin therapy (antioxidants plus zinc) for all indicated patients diagnosed with age-related macular degeneration (AMD).

DESIGN

We compared the impacts of vitamin therapy with those of no vitamin therapy using a computerized, stochastic, agent-based model. The model simulated the natural history of AMD and patterns of ophthalmic service use in the United States in a cohort from age 50 years until 100 or death.

PARTICIPANTS AND/OR CONTROLS

The model created 20 million simulated individuals. These individuals each received both the intervention (vitamin therapy after diagnosis) and the control (no vitamin therapy). Expected outcomes generated when vitamins were taken after diagnosis were compared with the expected outcomes generated when they were not.

METHODS

The model created individuals representative of patients in the U.S. Incidence of early AMD was based on published studies, as was vision loss and response to choroidal neovascularization therapies. Post-incident disease progression was governed by previously unpublished data drawn from the Age-Related Eye Disease Study.

MAIN OUTCOME MEASURES

Extent of disease progression, years and severity of visual impairment, cost of ophthalmic care and nursing home services, and quality-adjusted life years (QALYs). Costs and benefits were considered from the health care perspective and discounted using a 3% rate. The analysis was run for 50 years starting in 2003.

RESULTS

Compared with no therapy, vitamin therapy yielded a cost-effectiveness ratio of $21,387 per QALY gained and lowered the percentage of patients with AMD who ever developed visual impairment in the better-seeing eye from 7.0% to 5.6%.

CONCLUSIONS

Our model demonstrates that vitamin therapy for AMD improves quality of life at a reasonable cost.

Age-related macular degeneration: economic burden and value-based medicine analysis

It can be estimated that 17,100 new cases of neovascular (wet) AMD and 180,000 new cases of geographic-atrophy (dry) AMD occur in Canada annually. In addition to having a devastating effect on patients' lives, the condition causes significant adverse consequences for the economy. The deleterious effect of AMD on quality of life is markedly underestimated by ophthalmologists who treat patients with AMD, by non-ophthalmic physicians and by the public. In fact, patients with different degrees of severity of AMD have a perceived impairment of their quality of life that is 96% to 750% greater than the impairment estimated by treating ophthalmologists. Mild AMD causes a 17% decrease in the quality of life of the average patient, a decrease similar to that encountered with symptomatic human immunodeficiency virus infection or moderate cardiac angina. Moderate AMD produces a 40% decrease in quality of life, a decrease similar to that associated with permanent renal dialysis or severe cardiac angina. Very severe AMD causes a 63% decrement in quality of life, a decrease similar to that encountered with advanced prostatic cancer with uncontrollable pain or a severe stroke that leaves a person bedridden, incontinent and requiring constant nursing care. The adverse economic consequences of AMD include an annual $2.6 billion negative impact on Canada's gross domestic product. The return on investment is high for both current AMD therapies and research into new treatment modalities.

Treatment of age-related macular degeneration

Age-related macular degeneration (AMD) is the greatest cause of legal blindness in the western world. Established treatments include argon laser photocoagulation of extrafoveal choroidal neovascularisation (CNV) and photodynamic therapy of selected sub-foveal CNV. Newer approaches are targeting the angiogenic pathway in CNV development. Currently, other treatment modalities, such as radiotherapy and transpupillary thermotherapy do not have a clear role to play. Surgical options are experimental and only available in some centres for selected patients. Prevention of AMD remains elusive. Dietary supplements may have a role, while statins and prophylactic laser photocoagulation of drusen remain experimental. This paper explains the principles behind these approaches.

Verteporfin

Photodynamic therapy (PDT) with verteporfin (Visudyne), a photosensitising protoporphyrin derivative, is used in the management of subfoveal choroidal neovascularisation (CNV) secondary to age-related macular degeneration (AMD) or pathological myopia (PM). PDT with verteporfin over 1 and 2 years reduces the decline in visual acuity in patients with classic-containing subfoveal CNV secondary to AMD. Verteporfin is generally well tolerated by most patients. Verteporfin is also effective in patients with CNV secondary to PM, although data in this indication are limited and further controlled studies are required. Although verteporfin has shown efficacy in patients with occult AMD-related subfoveal CNV lesions in early trials, data are currently limited on its first-line use in this indication; fully published data from the Verteporfin In Occult (VIO) trial are therefore awaited with interest. Verteporfin should be considered as a first-line treatment in patients with predominantly classic subfoveal CNV secondary to AMD, and in patients with smaller minimally classic subfoveal CNV lesions. It may also be considered an option for the treatment of patients with occult AMD-related subfoveal CNV in whom visual acuity decreases or predominantly classic features develop over time.