Predicting intraocular pressure change before initiating therapy: timolol versus latanoprost

Cost-Utility Analysis of a Medication Adherence-Enhancing Educational Intervention for Glaucoma

OBJECTIVE

To evaluate the cost utility of a glaucoma medication-enhancing intervention compared to standard of care over a lifetime from the United States Department of Veterans Affairs (VA) payer perspective.

DESIGN

Model-based cost-utility analysis of a glaucoma medication-enhancing intervention from a randomized clinical trial.

SUBJECTS

Veterans with glaucoma, or suspected glaucoma who were prescribed topical glaucoma medications, had their visual field assessed within the last 9 months, and endorsed poor glaucoma medication adherence.

METHODS

Veterans were randomized either to a behavioral intervention to promote adherence or to a standard of care (control) session about general eye health. A decision analytic model was developed to simulate lifelong costs and quality-adjusted life years (QALYs) for an intervention tested in a randomized clinical trial at a single VA eye clinic. Costs included direct medical costs that the VA payer would incur, as informed initially by the clinical trial and then by published estimates. Health-state quality of life was based on published utility values. Scenario analyses included addition of booster interventions, a 3% decline in chance of staying medication adherent annually, and the combination of the two. Analyses were also conducted in the following subgroups: those with companion versus not, and those with once-daily versus more than once-daily dosing frequency.

MAIN OUTCOME MEASURES

Incremental cost-effectiveness ratio (ICER).

RESULTS

Compared to standard of care, the intervention dominated resulting in lower costs ($23 339.28 versus $23 504.02) and higher QALYs (11.62 versus 11.58). Among the 4 subgroups, the intervention dominated for 3 of them. In the fourth subgroup, those with more than once-daily dosing, the ICER was $2625/QALY. Compared to standard of care, an intervention with booster interventions led to an ICER of $3278/QALY. Assuming both a 3% annual loss in chance of continuing to be adherent and addition of booster interventions, the ICER increased to $71 371/QALY.

CONCLUSIONS

From a VA payer perspective over a lifetime, the glaucoma medication-enhancing behavioral intervention dominated standard of care in terms of generating cost savings and greater QALYs.

FINANCIAL DISCLOSURES

Proprietary or commercial disclosure may be found after the references.

Contributing ocular comorbidity to end-of-life visual acuity in medically treated glaucoma patients, ocular hypertension and glaucoma suspect patients

AIM

To assess the visual acuity at the end of life in glaucoma suspect patients, ocular hypertension, and patients treated for glaucoma and to find factors contributing to a reduced visual acuity in this cohort of deceased patients.

METHODS

In a cohort of 3883 medically treated glaucoma patients, glaucoma suspect, or patients with ocular hypertension assembled in 2001-2004, 1639 were deceased. Patient data were collected from electronic and paper patient files. The files of 1378 patients were studied and the last measured visual acuity and ocular comorbidities influencing the visual acuity were extracted.

RESULTS

Our results show that only 37.2% of patients had no visual impairment in either eye, 30.5% was visually impaired or blind in both eyes and 4.1% was blind in both eyes, all based on VA. The most common contributing factors for severe visual impairment or blindness (prevalence ≥ 1%) were: glaucoma, retinal vein occlusion, dry and exudative age-related macular degeneration, past retinal detachment, amblyopia, diabetic retinopathy, anterior ischemic optic neuropathy, trauma, decompensated cornea, past keratitis, enucleation, corneal transplantation, and macular hole.

CONCLUSIONS

Despite the current advanced treatment modalities for glaucoma, 30.5% of patients had a VA < 0.5 in both eyes and 4.1% was blind in both eyes. However, this disability cannot be confidently attributed only to glaucoma. Besides glaucoma, most common contributing factors were among others retinal and macular diseases. Patient management in glaucoma should be based on more than lowering the intraocular pressure to prevent blindness at the end of life.

Cost-Utility Analysis of Glaucoma Medication Adherence

PURPOSE

The majority of patients with glaucoma do not take their medications as prescribed. Estimates of the cost-utility value of adherence to prescribed glaucoma medication are vital to implement potentially effective interventions.

DESIGN

Cost-utility analysis using Monte Carlo microsimulations incorporating a series of Markov cycles (10 000 iterations per strategy).

PARTICIPANTS

Patients with glaucoma aged ≥40 years with a full lifetime horizon (up to 60 years).

METHODS

The analysis estimated glaucomatous progression on the basis of data from the United Kingdom Glaucoma Treatment Study. Participants with glaucoma entered the model at age 40 years with a mean deviation in the better-seeing eye of -1.4±-1.9 decibels (dB) and -4.3±-3.4 dB in the worse-seeing eye. Participants whose glaucoma worsened each year accumulate -0.8 dB loss compared with -0.1 dB loss for those who remained stable. Data from the Glaucoma Laser Trial and the Tube versus Trabeculectomy Studies were used to assign probabilities of worsening disease among treated patients. Claims data estimating rates of glaucoma medication adherence over 4 years were used to assign probability of adherence. Those with poor adherence were modeled as having outcomes similar to the placebo arm of the clinical trials. As patients' mean deviation deteriorated, they transitioned between health states from mild (≥-6 dB), to moderate (<-6 to ≥-12 dB), to severe glaucoma (<-12 to ≥23 dB), to unilateral (<-20 dB) and bilateral blindness. At each health state, patients incurred the costs of treatment and established health utilities; ultimately, societal costs of low vision and blindness were included.

MAIN OUTCOME MEASURES

Cost and quality-adjusted life year (QALY) of glaucoma medication adherence.

RESULTS

Beginning at an initial glaucoma diagnosis at age 40 years, patients proceeded to single-eye blindness as early as 19 years among those who were nonadherent and 23 years for those remaining adherent. Total healthcare costs for adherent patients averaged $62 782 (standard deviation [SD], 34 107), and those for nonadherent patients averaged $52 722 (SD, 38 868). Nonadherent patients had a mean loss of 0.34 QALYs, resulting in a cost-effectiveness ratio of $29 600 per QALY gained.

CONCLUSION

At a conservative willingness to pay of $50 000/QALY, there is room to expand services to improve patient adherence.

Prediction of Glaucomatous Visual Field Progression Using Baseline Clinical Data

PURPOSE

To develop a prediction model for glaucomatous visual field progression using easily accessible baseline clinical data.

PATIENTS AND METHODS

We collected baseline data of 613 consecutive patients with open-angle glaucoma from 2001 to 2003. The rate of visual field progression was calculated using the Visual Field Index (VFI) of routine follow-up examinations until 2010. Baseline data of 333 patients from 3 hospitals were used to develop a model to predict the rate of VFI progression using a linear regression analysis and univariate preselection (P<0.1) of 8 candidate predictors. The performance of the model was investigated using R, the area under the receiver-operating characteristic curve, and calibration plots. The prediction model was internally validated using bootstrapping and externally validated in 280 patients from 2 other hospitals.

RESULTS

After a mean follow-up period of 5.8 years of all 613 eyes, the mean rate of VFI progression was -1.6% per year. The final model contained the following predictors: age, baseline intraocular pressure, and baseline visual field status. During model development, 10.3% of the observed variation in VFI rates was explained by the model. The area under the receiver-operating characteristic curve was 0.76 when the prediction model was used to detect a VFI rate of -3% per year or worse, which decreased to 0.71 at external validation.

CONCLUSIONS

Although our prediction model could explain only a small amount of the variance in visual field progression, it may offer the possibility to identify subgroups of treated patients with high rates of visual field progression, thereby providing an opportunity to select those patients for more intensive treatment.

The long-term outcomes of four alternative treatment strategies for primary open-angle glaucoma

PURPOSE

To evaluate the long-term effects and costs of four treatment strategies for primary open-angle glaucoma compared to usual care.

METHODS

Cost-effectiveness analyses with a lifelong horizon were made from a societal perspective. Data were generated with a patient-level model based on discrete event simulation. The model structure and parameter estimates were based on literature, particularly clinical studies on the natural course of glaucoma and the effect of treatment. We simulated heterogeneous cohorts of 3000 patients and explored the impact of uncertainty with sensitivity analyses.

RESULTS

The incremental cost-effectiveness ratio (ICER) of initial treatment with a prostaglandin analogue compared with a β-blocker was €12.931 per quality-adjusted life year (QALY) gained. A low initial target pressure (15 mmHg) resulted in 0.115 QALYs gained and €1550 saved compared to a gradual decrease from 21 to 15 mmHg upon progression. Visual field (VF) measurements every 6 rather than 12 months lead to health gains at increased costs (ICER €173,486 per QALY gained), whereas measurements every 24 months lead to health losses at reduced costs (ICER €21,516 per QALY lost). All treatment strategies were dominant over 'withholding treatment'.

CONCLUSIONS

From a cost-effectiveness point of view, it seems advantageous to aim for a low intraocular pressure in all glaucoma patients. The feasibility of this strategy should therefore be investigated. Additionally, the cost-effectiveness outcomes of initiating monotherapy with a prostaglandin analogue and reducing the frequency of VF testing may be acceptable.

[Comparison of primary medicament therapy effects and primary argon laser trabeculoplasty on regulation of intraocular pressure and stability of perimetry findings in open angle glaucoma]

INTRODUCTION/AIM

Argon Laser Trabeculoplasty (ALT) is a recognized method for reducing intraocular pressure (IOP) in patients with open angle glaucoma. The aim of this study was to compare the effects of primary medicament therapy and primary ALT on IOP regulation and stability of perimetry findings.

METHODS

A total of 50 eyes of 35 patients were treated with primary ALT while 50 eyes of 36 patients were treated with primary medicament therapy with 0.5% timolol with 20, 0.005% latanoprost 18 and with 2% dorzolamid 12 eyes. IOP was controled at 3 months, and the visual field at 6 months during a 30-month follow-up period.

RESULTS

In the first 24 months of follow-up there was no statistically significant difference in percentage of eyes with successfully regulated IOP. At 27th and 30th month, in the group primarily treated with medicaments a statistically significant higher percentage of successfully regulated IOP was observed in 98%, and 96% of the eyes, respectively, while in the group primarily treated with ALT the decline in the percentage of successfully regulated IOP was observed in 78% and 76% of the eyes, (chi2-test, p = 0.002, p = 0.140). Both therapy groups showed stability of perimetry findings without statistically significant difference in the values of mean deviation (MD) index until the end of the monitoring period. The dynamics of change in MD index value showed a statistically significant greater decline in this parameter in subjects who had been primarily treated with medications during the last six months of follow-up, (two-factor analysis of variance with a repeated measurement, factor of time x type of therapy, p = 0.030).

CONCLUSION

Primary ALT equally successfully regulates IOP and restores stability of perimetry findings in patients with open angle glaucoma like the primary medicament therapy.

A randomized, 36-month, post-marketing efficacy and tolerability study in Sweden and Finland of latanoprost versus non-prostaglandin therapy in patients with glaucoma or ocular hypertension

PURPOSE

To compare the effect of time on therapy, efficacy, tolerability and resource utilization of latanoprost or non-prostaglandin analogues (non-PGs) in patients who required a change in intraocular pressure (IOP)-lowering monotherapy.

METHODS

This open-label, multicentre study (Sweden, 19 sites; Finland, seven sites) included adults with glaucoma or ocular hypertension with mean diurnal IOP > or = 21 mmHg on ocular hypotensive monotherapy. Patients were randomized to latanoprost monotherapy or non-PG therapy (commercially available therapy other than a PG) and followed for 36 months. End-points included: time to treatment failure (baseline to visit with a change in/addition to treatment); diurnal IOP (mean of 08.00, 12.00 and 16:00 hr measurements) at months 6, 12, 24 and 36; tolerability; and resource utilization, where analyses used Swedish and Finnish 2006 unit costs.

RESULTS

Three hundred and twenty-six patients received >or = 1 dose of latanoprost (n = 162) or non-PGs (n = 164). Median time to treatment failure was longer for latanoprost (36 months) than for non-PGs (12 months; p < 0.001); 51% and 24% of patients remained on randomized therapy after 36 months, respectively (p < 0.001). Decreases in mean diurnal IOP from baseline were significantly greater for latanoprost than for non-PGs at months 6 and 12 (p < 0.01). No serious adverse events were judged to be treatment-related. Mean total 36-month direct costs were similar in patients initiated with latanoprost and non-PGs.

CONCLUSION

Patients who failed previous monotherapy remained on therapy longer when switched to latanoprost. Latanoprost's IOP-reducing effect and tolerability were sustained over the long term. Resource utilization and costs were generally similar in those initiating latanoprost or non-PG therapy.

Evaluation of risk of falls and orthostatic hypotension in older, long-term topical beta-blocker users

BACKGROUND

Falls are a serious problem in the elderly, and have recently been described as cardiovascular-mediated side effects of beta-blocker eye drops. Therefore, we investigated the possible association between the long-term use of beta-blockers, prostaglandins and their combinations in eye drops, and falls, dizziness and orthostatic hypotension in older patients.

METHODS

All participants were long-term users of eye drops containing beta-blockers, prostaglandins or their combinations. They underwent a structured falls interview and blood pressure measurement for testing of orthostatic hypotension. The odds ratio for presence of orthostatic hypotension or a positive falls history according to use of beta-blocker eye drops was calculated with a binary logistic regression analysis. The main outcome measures were a positive falls history and the presence of orthostatic hypotension.

RESULTS

In total, 148 of 286 subjects participated. After adjustment for age, gender, and use of fall-risk-increasing drugs other than beta-blocker eye drops, we found no significant difference in fall risk [odds ratio (OR): 0.60; 95% confidence interval (CI): 0.268-1.327] between patients using ophthalmic beta-blockers or a combination of ophthalmic beta-blockers and prostaglandins, and patients using ophthalmic prostaglandins only. Although prevalence of orthostatic hypotension was higher in the beta-blocker group (OR: 1.67; 95% CI: 0.731-3.793) compared to the prostaglandin group, this was a non-significant difference.

CONCLUSIONS

In our study, we did not find a significant association between long-term use of beta-blockers eye drops and falls, dizziness or orthostatic hypotension in older ophthalmic outpatients, compared to long-term use of prostaglandin eye drops.