Economic evaluation of prevention of cystoid macular edema after cataract surgery in diabetic patients: ESCRS PREMED study report 6.

PURPOSE: To investigate the cost-effectiveness of prophylactic treatments against cystoid macular edema after cataract surgery in diabetic patients. SETTING: 7 ophthalmology clinics in the Netherlands and Belgium. DESIGN: Prospective trial-based cost-effectiveness analysis using data from a European multicenter randomized clinical trial. METHODS: Diabetic patients (n = 163) undergoing uneventful cataract surgery were randomized to perioperative subconjunctival triamcinolone acetonide (n = 36), perioperative intravitreal bevacizumab (n = 36), combination treatment (n = 45), or no additional treatment (control group, n = 46). The cost analysis was performed from a healthcare perspective within a 12-week postoperative time horizon. The main effectiveness outcome was quality-adjusted life years (QALYs). The main cost-effectiveness outcome was the incremental cost-effectiveness ratio (ICER; cost per QALY). RESULTS: The mean total healthcare costs and QALYs were as follows: triamcinolone group €1827 (U.S. dollars [$] 2295)/0.166; bevacizumab group €2050 ($2575)/0.144; combination group €2027 ($2546)/0.166; and control group €2041 ($2564)/0.156. Bevacizumab and control treatment were most costly and least effective. The ICER was €321 984 ($404 503) per QALY for the combination group compared with that of the triamcinolone group. Assuming the willingness-to-pay as €20 000 ($25 126) per QALY, the cost-effectiveness probability was 70% and 23% in the triamcinolone and combination groups, respectively. No patient who received triamcinolone developed clinically significant macular edema (CSME). A secondary cost-effectiveness analysis based on this outcome showed a clear preference for triamcinolone. CONCLUSIONS: In diabetic patients, subconjunctival triamcinolone was effective in preventing CSME after cataract surgery. The cost-effectiveness analysis showed that triamcinolone is also cost-effective.

Economic evaluation of prevention of cystoid macular edema after cataract surgery in patients without diabetes: ESCRS PREMED study report 4.

PURPOSE: To investigate the cost-effectiveness of prophylactic treatments against cystoid macular edema (CME) after cataract surgery in patients without diabetes. SETTING: Seven ophthalmology clinics in the Netherlands and Belgium. DESIGN: Prospective cost-effectiveness analysis using data from a European multicenter randomized clinical trial (ESCRS PREMED). METHODS: Patients without diabetes planned for expected uneventful cataract surgery were randomized to topical bromfenac (Yellox, n = 242), topical dexamethasone (n = 242), or a combination treatment (n = 238). All relevant resources from a healthcare perspective were included in the cost analysis within a time horizon of 12 weeks postoperatively. The main effectiveness outcome was quality-adjusted life years (QALYs). The main cost-effectiveness outcome was the incremental cost-effectiveness ratio (ICER) based on the cost per QALY. RESULTS: The study comprised 722 patients without diabetes. Total healthcare costs and QALYs were € 447 (US $562) and 0.174 in the bromfenac group, €421 (US $529) and 0.179 in the dexamethasone group, and €442 (US $565) and 0.182 in the combination group. Bromfenac was most costly and least effective (ie, strongly dominated). The ICER was €6544 (US $8221) per QALY for the combination group compared with the dexamethasone group. Assuming that the willingness to pay is € 20 000 (US $25 126) per QALY, the cost-effectiveness probability was 3%, 32%, and 65% in the bromfenac, dexamethasone, and combination groups, respectively. CONCLUSIONS: In patients without diabetes, combination treatment with topical bromfenac and dexamethasone was effective and cost-effective in preventing CME after cataract surgery compared with treatment with either drug alone.

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.

Ocular hypertension and the risk of blindness.

PURPOSE: To estimate the risk of blindness in patients with ocular hypertension (OHT) using an appropriate model and current empirical data. DESIGN: A Markov model with data from a systematic literature review. METHODS: A Markov model with 3 health states was built: OHT, primary open-angle glaucoma (POAG), and unilateral blindness. Literature was searched for reports on conversion from OHT to POAG and progression from POAG to blindness, to estimate a range of annual conversion and progression probabilities. The model had a cycle length of 1 year. RESULTS: The 15-year risk estimates ranged from 3.1% to 9.4% in untreated, and from 0.9% to 8.6% in treated patients with OHT. The ranges were the result of differences in patient populations, treatments, and outcome definitions in currently available empirical data. CONCLUSIONS: The best estimates of the 15-year risk of unilateral blindness in patients with OHT, based on the currently available empirical data and an appropriate model, show that the risk is <10%.

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 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 19,367; 26,746; and 30,520, with 2.16; 2.17; and 2.15 QALYs, respectively. Costs associated with ranibizumab PRN and 1×/month were 45,491 and 74,837 with 2.16 and 2.15 QALYs, respectively. 'No treatment' was associated with 9530 and 1.96 QALYs. The incremental cost-effectiveness ratios versus 'no treatment' were: aflibercept-140,274; bevacizumab-51,062 (ABC PRN), 83,256 (CATT PRN) and 110,361 (1×/month); ranibizumab-181,667 (PRN) and 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.

The long term effectiveness and cost-effectiveness of initiating treatment for ocular hypertension.

PURPOSE: To investigate the long-term health and economic consequences of direct treatment initiation in ocular hypertension patients. METHODS: A cost-effectiveness analysis with a societal perspective and a lifelong horizon was performed. The primary outcomes were the incremental quality-adjusted life years (QALYs) and costs of direct pressure-lowering treatment for ocular hypertension, compared to a strategy where treatment is postponed until conversion to glaucoma has been observed. We used a decision analytic model based on individual patient simulation to forecast disease progression and treatment decisions in both strategies in a representative heterogeneous patient population and in 18 patient subgroups stratified by initial intraocular pressure and additional risk factors for conversion. RESULTS: The incremental discounted health gain of direct treatment was 0.27 QALYs, whereas the incremental discounted costs were -€ 649 during an average lifetime of 26 years. In the simulations of patient subgroups, the model outcomes moved towards higher health gains and lower incremental costs with increasing risk of conversion in the patient population. The incremental cost-effectiveness ratio of direct treatment ranged from € 15,425 per QALY gained in the lowest-risk subgroup to dominance in the highest-risk subgroup. Probabilistic sensitivity analysis indicated that uncertainty surrounding the model input parameters did not affect the conclusions. CONCLUSION: Direct, early, pressure-lowering treatment is a dominant cost-effective treatment strategy over a strategy to start the same treatment approach later, after glaucoma has occurred for patients with ocular hypertension. Its implementation and consequences should be discussed with ophthalmologists and individual patients.

Economic evaluation of endothelial keratoplasty techniques and penetrating keratoplasty in the Netherlands.

PURPOSE: To evaluate cost-effectiveness of penetrating keratoplasty (PK), femtosecond laser-assisted Descemet stripping endothelial keratoplasty (FS-DSEK), and Descemet stripping automated endothelial keratoplasty (DSAEK). DESIGN: Cost-effectiveness analysis based on data from a randomized multicenter clinical trial and a noncomparative prospective study. METHODS: Data of 118 patients with corneal endothelial dysfunction were analyzed in the economic evaluation. Forty patients were included in the PK group, 36 in the FS-DSEK group, and 42 in the DSAEK group. The primary incremental cost-effectiveness ratio (ICER) was the incremental costs per clinically improved patient, defined as a patient with a combined effectiveness of both a clinically improved BSCVA (defined as an improvement of at least 2 lines) and a clinically acceptable refractive astigmatism (defined as less than or equal to 3.0 diopters). Analysis was based on a 1-year follow-up period after transplantation. RESULTS: The percentage of treated patients who met the combined effectiveness measures was 52% for DSAEK, 44% for PK, and 43% for FS-DSEK. Mean total costs per patient were €6674 (US$7942), €12 443 (US$14 807), and €7072 (US$8416) in the PK group, FS-DSEK group, and DSAEK group, respectively. FS-DSEK was less effective and more costly compared to both DSAEK and PK. DSAEK was more costly but also more effective compared to PK, resulting in incremental costs of €4975 (US$5920) per additional clinically improved patient. CONCLUSIONS: The results of this study show that FS-DSEK was not cost-effective compared to PK and DSAEK. DSAEK, on the other hand, was more costly but also more effective compared to PK. Including societal costs, a longer follow-up period and preparation of the lamellar transplant buttons in a national cornea bank could improve the cost-effectiveness of DSAEK.

The influence of the assessment method on the incidence of visual field progression in glaucoma: a network meta-analysis.

PURPOSE: To study and quantify the difference in incidence of progression between methods for the assessment of glaucomatous visual field progression. METHODS: We identified 2450 articles published up to April 2009 in the following data sources: PubMed, EMBASE, and Cochrane. Ten studies covering 30 methods were included. All studies aimed to compare different methods for the assessment of glaucomatous visual field progression in the same study population. A network meta-analysis using a mixed-effects model was performed to combine within-study between-method comparisons with indirect comparisons from other studies. The summarized incidence of progression was calculated for every method, and methods were ranked according to this incidence. RESULTS: In total, methods were compared in 1040 eyes of 948 patients with glaucoma. On average, 21% of the eyes progressed. When all 30 methods were ranked, the incidence ranged from 2% to 62%. These incidences are corrected for a baseline mean deviation (MD) value of -7 decibels and a mean follow-up time of 6 years. Besides the assessment method, the incidence was only determined by the follow-up period and baseline MD value, leaving no unexplained variance in the incidence of progression. CONCLUSION: The incidence of progression varies considerably between different studies. This is mainly caused by the variety of methods used to assess progression but also by differences in follow-up time and baseline visual field loss.

Latanoprost versus timolol as first choice therapy in patients with ocular hypertension. A cost-effectiveness analysis.

PURPOSE: To determine the cost-effectiveness of ocular hypertension (OH) treatment initiated with latanoprost compared to timolol. METHODS: Two strategies for OH therapy are modelled, (1) 'starting with timolol' and (2) 'starting with latanoprost'. Therapy can be maintained or changed dependent on the achieved intraocular pressure (IOP) and side-effects. Adjustments of therapy to reach a target pressure involve monotherapy, combination therapy and laser. Four drugs are used: latanoprost, timolol, brimonidine and dorzolamide. Once the adjustments of therapy are completed, lifelong follow-up with IOP-dependent conversion to glaucoma and progression to blindness are modelled. Direct medical costs are assigned. The IOP-lowering effect of drugs is based on meta-analyses and applied by Monte Carlo simulation to a hypothetical cohort of patients with OH. The characteristics of the cohort, including the initial IOP distribution, are based on data of 1000 patients. RESULTS: The IOP decreased from 25,4 mm Hg (mean) to 16.7 (±0.017) mm Hg (strategy 1) and to 16.5 (±0.013) mm Hg (strategy 2). Costs per patient within 15 months of therapy were € 367 and € 469, respectively. Lifetime blindness and costs were 0.0334 years and € 3,514 (strategy 1) and 0.0318 years and € 4,397 (strategy 2). Incremental costs per year of vision saved for strategy (2) in comparison with strategy (1) amount to, given the uncertainties in the model, approximately € 537,000. CONCLUSION: For saving 1 year of vision, high costs are needed when OH therapy is initiated with latanoprost compared to timolol, when the cost price of latanoprost remains high.

The clinical impact of 2 different strategies for initiating therapy in patients with ocular hypertension.

PURPOSE: To assess the impact of 2 strategies for initiating therapy in ocular hypertension (OH) on drug use, intraocular pressure (IOP), and blindness caused by glaucoma. METHODS: Using a simulation model, initiating therapy with timolol (strategy 1) and with latanoprost (strategy 2) was simulated for a hypothetic cohort of ocular hypertension patients with an initial IOP distribution (data of 1000 patients). Adjustment of therapy within 15 months and a subsequent lifelong follow-up, with an IOP dependent conversion to glaucoma, were modeled. The IOP lowering effect of medication (based on a meta-analysis) was applied by Monte Carlo simulation. Therapy could be maintained or changed, depending on the achieved IOP and side effects. Four drugs (latanoprost, timolol, brimonidine, dorzolamide) were used as monotherapy or in combination. Glaucoma conversion rate was based on literature. RESULTS: Treatment goal was achieved in both strategies in 90% by monotherapy. This was 60% for patients with initial IOP's of 30 mm Hg. The originally prescribed medication was maintained in 66% (1) and in 77% (2). IOP decreased with approximately 34%, from 25.4 mm Hg (mean) to 16.7 mm Hg (1) and to 16.5 mm Hg (2) Blindness per person within 18.7 years of life expectancy was 0.0923 years (1) and 0.0870 years (2), which corresponds to approximately 1 month. The difference between strategies was 2 days spent in blindness per patient. CONCLUSIONS: The difference in clinical effects of the strategies is small. This is largely owing to the key concept of a target pressure, which underlies both strategies.

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.

Prevalence and determinants of non-adherence to topical hypotensive treatment in Dutch glaucoma patients.

BACKGROUND: To assess the prevalence and determinants of non-adherence to topical hypotensive treatment in glaucoma patients in order to support interventions targeting enhancement of patient adherence. METHODS: One-hundred and sixty-six glaucoma patients, recruited by nationwide multi-stage sampling, filled in an extensive and carefully developed questionnaire covering various theoretically relevant determinants of patient adherence which were categorized as psychosocial aspects, barriers and skills. RESULTS: Prevalence of self-reported non-adherence was 27.3%. Younger patients (<55 years of age) had a higher risk of being non-adherent. Forgetfulness, unavailability of eye drops and difficulties with holding the bottle above the eye when applying the eye drops were the most cited reasons for non-adherence. Fifty percent of the patients indicated that they required more information on the correct administration of eye drops. There was no association between non-adherence and sex, level of education, type of insurance, duration of disease or family history of glaucoma. CONCLUSIONS: Non-adherence to topical glaucoma medication is fairly common. Aids that minimize forgetfulness and delivery systems facilitating the delivery of medications to the eye could be considered to enhance patient adherence before advancing to other therapies with additional risks and costs.

Does pretreatment testing for serotonin transporter polymorphisms lead to earlier effects of drug treatment in patients with major depression? A decision-analytic model.

BACKGROUND: An estimated 30% to 40% of patients with depression do not sufficiently respond to treatment with selective serotonin reuptake inhibitors (SSRIs) and the period in which treatment efficacy can be assessed is relatively long. Therefore, a test to identify potential nonresponders could be useful in the treatment of depression. Serotonin transporter gene (SLC6A4) variations have been reported to account for differences in the way individuals respond to SSRI treatment. OBJECTIVE: A decision-analytic model was used to assess whether pretreatment genetic testing for 5-HTTLPR, a polymorphism of the SLC6A4 genotype, could be an efficient tool in the treatment of depression. METHODS: A theoretical clinical decision-analytic model was constructed to compare the current treatment strategy in The Netherlands with an alternative strategy for the treatment of depression. Under treatment guidelines in The Netherlands, all patients with depression receive SSRI treatment (nontesting strategy). Under the alternative strategy, genetic testing would be performed to identify which class of antidepressant would be the best choice for initiation of treatment (genetic testing strategy). Probabilities (predicted results) for this model were based on data from previous studies and the opinions of experts in the field of psychopharmacology. To test the robustness of the model, 6- and 12-week remission rates for patients treated with SSRIs were varied in a sensitivity analysis using a predetermined range that was established based on expert opinion. Threshold analyses were performed on the parameters of serotonin transporter genotype frequency and response and nonresponse rates for patients receiving SSRIs, serotonin-norepinephrine reuptake inhibitors (SNRIs), and tricyclic antidepressants (TCAs) to determine the value for a variable at which it could be concluded that a change in treatment strategy would be preferred. RESULTS: When genetic testing was performed before an antidepressant was prescribed, 64.6% of patients were predicted to be in remission after 6 weeks of treatment compared with 60.0% of patients who did not receive genetic testing. After 12 weeks, 79.5% of patients in the testing group who received an SNRI as initial treatment and 83.2% of those who received a TCA initially were predicted to be in remission compared with 76.7% of patients in the nontesting group. Sensitivity analyses indicated that the model was robust to variation of probability estimates within their plausible ranges. However, these findings were based on a theoretic model and did not include cost assessment. Pretreatment genetic testing must be evaluated further in randomized clinical trials and costs must be assessed before implementing this strategy in routine psychiatric practice can be recommended. CONCLUSIONS: The findings of this study suggest that performing genetic testing before prescribing antidepressant treatment may lead to greater numbers of patients experiencing remission early in treatment.

Cost effectiveness of an adherence-improving programme in hypertensive patients.

BACKGROUND: Non-adherence to antihypertensive drugs is high, and the economic consequences of non-adherence may be substantial. The Medication Events Monitoring System (MEMS), which is a method to improve adherence, has been shown to be a useful tool for the management of adherence problems. OBJECTIVE: To assess the cost effectiveness of the MEMS compared with usual care in a population of hypertensive patients with poor adherence. The MEMS programme consisted of provision of containers fitted with electronic caps together with adherence training if indicated. METHODS: In a randomised controlled trial, 164 hypertensive patients in the experimental strategy and 89 patients in the usual care strategy were followed for 5 months. Patients who had a systolic blood pressure (SBP) > or = 160 mm Hg and/or diastolic BP (DBP) > or = 95 mm Hg despite the use of antihypertensive drugs were eligible. Patients were recruited by a GP, and treatment took place in general practice. In the experimental strategy, electronic monitoring of the intake of antihypertensive drugs was introduced without change of medication. Unsatisfactory adherence was defined as < 85% of days with the number of doses taken as prescribed. In the usual care strategy, antihypertensive treatment was intensified by the addition or change of antihypertensive drugs, if necessary, without provision of an electronic monitor. Outcome parameters included the proportion of patients with normalised blood pressure (NBP) at 5 months and QALYs. Costs were quantified from the healthcare and societal perspective. Non-parametric bootstrap simulations were performed to quantify the uncertainty around the mean estimates and cost-effectiveness acceptability curves were presented. In addition, a number of univariate sensitivity analyses were performed on deterministic variables. RESULTS: At 5 months, 3.1% (95% UI [uncertainty interval] -9.7%, +15.8%) more patients had NBP, and 0.003 (95% UI -0.005, +0.010) more QALYs were generated in the experimental strategy. A statistically significant lower percentage of patients had a dose escalation in the experimental strategy. Irrespective of the ceiling ratio for cost effectiveness, the cost-effectiveness probability was between 75% and 80% for the analysis from the healthcare perspective using proportion of patients with NBP as the outcome parameter. For the analysis from the societal perspective using QALYs as the outcome parameter, this probability was between 45% and 51%. CONCLUSION: For a time horizon of 5 months, a difference in both cost and effect could not be detected between an adherence-improving programme compared with usual care for hypertensive patients. The probability that the adherence-improving programme is cost effective is at best moderate. Moreover, the cost-effectiveness result is surrounded with considerable uncertainty and large-scale implementation warrants additional research into the economic consequences of this intervention. Patients may benefit from the use of a MEMS monitor in situations where BP targets are not reached because of suspected non-adherence and both patient and GP are reluctant to increase the dose or number of antihypertensive drugs.

Socioeconomic differences in glaucoma patients' knowledge, need for information and expectations of treatments.

PURPOSE: To study the specific items for which socioeconomic differences in glaucoma patients' knowledge, need for information and expectations of treatments exist, with the aim of developing a patient education programme. METHODS: A total of 44 randomly selected ophthalmologists assigned 166 consecutive outpatient glaucoma patients to complete a questionnaire that had been systematically developed based on focus group interviews, suggestions from several experts and a pilot test. Topics included knowledge about glaucoma and its treatment, need for information and expectations of treatment. Educational level was used as a measure for socioeconomic status. Logistic regression analysis was conducted to adjust for age, sex and duration of glaucoma. RESULTS: After adjusting for age, sex and duration of glaucoma, knowledge of glaucoma and its treatment was found to be positively correlated with socioeconomic status. Items on knowledge with socioeconomic differences concerned risk factors, pathophysiology and consequences of glaucoma, as well as effects and adverse effects of treatments. The lowest socioeconomic group demonstrated more need for information on public assistance and practical aspects of glaucoma and more often expected that glaucoma damage could be repaired. CONCLUSION: Important socioeconomic differences in knowledge, need for information and expectations of treatment exist in glaucoma patients. Patient education should focus on every glaucoma patient, but better information for the lower socioeconomic groups about specific items mentioned in this study might reduce the negative effects of low socioeconomic status on visual impairment.

All that glisters is not gold: a comparison of electronic monitoring versus filled prescriptions--an observational study.

BACKGROUND: Poor compliance with antihypertensive medication is assumed to be an important reason for unsatisfactory control of blood pressure. Poor compliance is difficult to detect. Each method of measuring compliance has its own strengths and weaknesses. The aim of the present study was to compare patient compliance with antihypertensive drugs as measured by two methods, electronic monitoring versus refill compliance. METHODS: 161 patients with a diagnosis of hypertension for at least a year prior to inclusion, and inadequate blood pressure control (systolic blood pressure > or = 160 mmHg and/or diastolic blood pressure > or = 95 mmHg) despite the use of antihypertensive drugs, were included. Patients' pharmacy records from 12 months prior to inclusion were obtained. Refill compliance was calculated as the number of days for which the pills were prescribed divided by the total number of days in this period. After inclusion compliance was measured with an electronic monitor that records time and date of each opening of the pillbox. Agreement between both compliance measures was calculated using Spearman's correlation coefficient and Cohen's kappa coefficient. RESULTS: There was very little agreement between the two measures. Whereas refill compliance showed a large range of values, compliance as measured by electronic monitoring was high in almost all patients with estimates between 90% and 100%. Cohen's kappa coefficient was 0.005. CONCLUSION: While electronic monitoring is often considered to be the gold standard for compliance measurements, our results suggest that a short-term electronic monitoring period with the patient being aware of electronic monitoring is probably insufficient to obtain valid compliance data. We conclude that there is a strong need for more studies that explore the effect of electronic monitoring on patient's compliance.