Impact of insecticide resistance in Anopheles arabiensis on malaria incidence and prevalence in Sudan and the costs of mitigation.

Insecticide-based interventions have contributed to ∼78% of the reduction in the malaria burden in sub-Saharan Africa since 2000. Insecticide resistance in malaria vectors could presage a catastrophic rebound in disease incidence and mortality. A major impediment to the implementation of insecticide resistance management strategies is that evidence of the impact of resistance on malaria disease burden is limited. A cluster randomized trial was conducted in Sudan with pyrethroid-resistant and carbamate-susceptible malaria vectors. Clusters were randomly allocated to receive either long-lasting insecticidal nets (LLINs) alone or LLINs in combination with indoor residual spraying (IRS) with a pyrethroid (deltamethrin) insecticide in the first year and a carbamate (bendiocarb) insecticide in the two subsequent years. Malaria incidence was monitored for 3 y through active case detection in cohorts of children aged 1 to <10 y. When deltamethrin was used for IRS, incidence rates in the LLIN + IRS arm and the LLIN-only arm were similar, with the IRS providing no additional protection [incidence rate ratio (IRR) = 1.0 (95% confidence interval [CI]: 0.36-3.0; P = 0.96)]. When bendiocarb was used for IRS, there was some evidence of additional protection [interaction IRR = 0.55 (95% CI: 0.40-0.76; P < 0.001)]. In conclusion, pyrethroid resistance may have had an impact on pyrethroid-based IRS. The study was not designed to assess whether resistance had an impact on LLINs. These data alone should not be used as the basis for any policy change in vector control interventions.

The effectiveness and cost-effectiveness of donepezil, galantamine, rivastigmine and memantine for the treatment of Alzheimer's disease (review of Technology Appraisal No. 111): a systematic review and economic model.

BACKGROUND: Alzheimer's disease (AD) is the most commonly occurring form of dementia. It is predominantly a disease of later life, affecting 5% of those over 65 in the UK. OBJECTIVES: Review and update guidance to the NHS in England and Wales on the clinical effectiveness and cost-effectiveness of donepezil, galantamine, rivastigmine [acetylcholinesterase inhibitors (AChEIs)] and memantine within their licensed indications for the treatment of AD, which was issued in November 2006 (amended September 2007 and August 2009). DATA SOURCES: Electronic databases were searched for systematic reviews and/or metaanalyses, randomised controlled trials (RCTs) and ongoing research in November 2009 and updated in March 2010; this updated search revealed no new includable studies. The databases searched included The Cochrane Library (2009 Issue 4, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials), MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, PsycINFO, EconLit, ISI Web of Science Databases--Science Citation Index, Conference Proceedings Citation Index, and BIOSIS; the Centre for Reviews and Dissemination (CRD) databases--NHS Economic Evaluation Database, Health Technology Assessment, and Database of Abstracts of Reviews of Effects. REVIEW METHODS: The clinical effectiveness systematic review was undertaken following the principles published by the NHS CRD. We included RCTs whose population was people with AD. The intervention and comparators depended on disease severity, measured by the Mini Mental State Examination (MMSE). INTERVENTIONS: mild AD (MMSE 21-26)--donepezil, galantamine and rivastigmine; moderate AD (MMSE 10-20)--donepezil, galantamine, rivastigmine and memantine; severe AD (MMSE < 10)--memantine. Comparators: mild AD (MMSE 21-26)--placebo or best supportive care (BSC); moderate AD (MMSE 10-20)--donepezil, galantamine, rivastigmine, memantine, placebo or BSC; severe AD (MMSE < 10)--placebo or BSC. The outcomes were clinical, global, functional, behavioural, quality of life, adverse events, costs and cost-effectiveness. Where appropriate, data were pooled using pair-wise meta-analysis, multiple outcome measures, metaregression and mixedtreatment comparisons. The decision model was based broadly on the structure of the three-state Markov model described in the previous technology assessment report, based upon time to institutionalisation, parameterised with updated estimates of effectiveness, costs and utilities. RESULTS: Notwithstanding the uncertainty of our results, we found in the base case that the AChEIs are probably cost saving at a willingness-to-pay (WTP) of £'30,000 per qualityadjusted life-year (QALY) for people with mild-to-moderate AD. For this class of drugs, there is a > 99% probability that the AChEIs are more cost-effective than BSC. These analyses assume that the AChEIs have no effect on survival. For the AChEIs, in people with mild to moderate AD, the probabilistic sensitivity analyses suggested that donepezil is the most cost-effective, with a 28% probability of being the most cost-effective option at a WTP of £'30,000 per QALY (27% at a WTP of £'20,000 per QALY). In the deterministic results, donepezil dominates the other drugs and BSC, which, along with rivastigmine patches, are associated with greater costs and fewer QALYs. Thus, although galantamine has a slightly cheaper total cost than donepezil (£'69,592 vs £'69,624), the slightly greater QALY gains from donepezil (1.616 vs 1.617) are enough for donepezil to dominate galantamine.The probability that memantine is cost-effective in a moderate to severe cohort compared with BSC at a WTP of £'30,000 per QALY is 38% (and 28% at a WTP of £'20,000 per QALY). The deterministic ICER for memantine is £'32,100 per/QALY and the probabilistic ICER is £'36,700 per/QALY. LIMITATIONS: Trials were of 6 months maximum follow-up, lacked reporting of key outcomes, provided no subgroup analyses and used insensitive measures. Searches were limited to English language, The model does not include behavioural symptoms and there is uncertainty about the model structure and parameters. CONCLUSIONS: The additional clinical effectiveness evidence identified continues to suggest clinical benefit from the AChEIs in alleviating AD symptoms, although there is debate about the magnitude of the effect. Although there is also new evidence on the effectiveness of memantine, it remains less supportive of this drug's use than the evidence for AChEIs. The conclusions concerning cost-effectiveness are quite different from the previous assessment. This is because both the changes in effectiveness and costs between drug use and non-drug use underlying the ICERs are very small. This leads to highly uncertain results, which are very sensitive to change. RESEARCH PRIORITIES: RCTs to include mortality, time to institutionalisation and quality of life, powered for subgroup analysis. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Estimation of financial burden due to oversupply of medications for chronic diseases.

Given the potential of financial burden due to oversupply of medications for chronic diseases, this study aims to determine the prevalence of oversupply and to estimate the magnitude of financial loss in Thailand. Electronic patient database in a university-affiliated hospital in Thailand was used. Based on the utilization of top 5 high drug expenditure in 2005, the prevalence and the financial loss of oversupply (medication possession ratio [MPR] >1.00) were estimated. In total, 1893 patients were included in this study. The average age was 65.2 years and the majority were female (56%). The prevalence of oversupply ranged from 23.2% to 62.8%, whereas the annual financial loss ranged from US $4108 to US $10 517. The total amount of loss was US $32 903 or 3.77% of total medication costs. In summary, because of the high prevalence and associated high financial loss, oversupply of medication is a significant financial burden on hospitals and society.

Assessing the cost-effectiveness of the rivastigmine transdermal patch for Alzheimer's disease in the UK using MMSE- and ADL-based models.

OBJECTIVE: Assess long-term cost-effectiveness of rivastigmine patch in Alzheimer's disease (AD) management in the UK, using cognitive and functional models based on clinical trial efficacy data. METHODS: Incremental costs and Quality Adjusted Life Years (QALYs) associated with rivastigmine patch and capsule treatment versus best supportive care (BSC) were calculated using two economic models, one based solely on Mini-Mental State Examination (MMSE) scores, and one also incorporating activities of daily living (ADL) scores. The clinical pathway was populated with data from a clinical trial of rivastigmine patch (9.5 mg/24 h) and capsules (12 mg/day) versus placebo. Costs were based on the UK health and social care costs and basic UK National Health Service (NHS) prices. Disease progression was modelled beyond the trial period over 5 years using published equations to predict natural decline in AD patients. Base case costing variables included drugs, clinical monitoring, and institutionalization. RESULTS: The MMSE model estimated incremental costs per QALY of £10 579 for rivastigmine patch and £15 154 for capsule versus BSC. The MMSE-ADL model estimated incremental costs per QALY of £9114 for rivastigmine patch and £13 758 for capsules. The main difference between the models was a greater number of institutionalized days avoided for rivastigmine versus BSC estimated by the MMSE-ADL model. CONCLUSIONS: Both the MMSE and MMSE-ADL models suggest that rivastigmine patch and capsules are cost-effective treatments versus BSC. Incorporating ADL evidence makes a marginal but important difference to estimates in this case. Future economic evaluations of AD treatment should include measures of both cognition and functioning.

How do we treat people with dementia in Croatia.

The current clinical view on pharmacological treatment and the Croatian reality regarding approved antidementia drugs is presented. Dementia is a syndrome of high incidence and Alzheimer's disease is the most common cause of dementia. New data show that dementia prevalence will nearly double every 20 years, and we believe that current estimated number of persons with dementia (PWD) for Croatia is more than 80,000. The standard treatment with antidementia drugs is unavailable in Croatia, for the majority of PWD, because antidementia drugs are not on the reimbursement list, although Croatian algorithm for psychopharmacological treatment and Alzheimer Disease Societies Croatia recommend early and adequate treatment. Alzheimer's dementia is becoming a world's health priority in 21st century, so we strongly believe that antidementia drugs should be reimbursed in Croatia.

International price comparisons of Alzheimer's drugs: a way to close the affordability gap.

BACKGROUND: Alzheimer's drugs are believed to have limited availability and to be unaffordable in low- and middle-income countries compared to high-income countries. The price, availability and affordability of Alzheimer's drugs have not been reported before. METHODS: During 2007 an international survey was conducted in 21 countries in six continents (Argentina, Australia, Brazil, the Dominican Republic, France, India, Japan, Macedonia, Mexico, New Zealand, Nigeria, the Philippines, Portugal, Serbia, South Korea, Switzerland, Taiwan, Thailand, Uganda, the U.K. and the U.S.A.). Prices of Alzheimer's drugs were compared using the affordability index (the total number of units purchasable with one's daily income) derived from purchasing power parity (PPP) converted prices as well as raw prices. RESULTS: Donepezil is available in all 21 countries, whereas the newer drugs are less available. A 5 mg tablet of branded originator donepezil costs just US$0.26 in India and US$0.31 in Mexico, whereas it costs US$6.64 in the U.S.A. Pricing conditions of rivastigmine, galantamine and memantine appear to be similar to that of donepezil. The cheapest branded originators are from India and Mexico. However, in terms of PPP, Alzheimer's drugs in other low- and middle-income countries are much more expensive than in high-income countries. Most people in low- and middle-income countries cannot afford Alzheimer's drugs. CONCLUSIONS: Alzheimer's drugs, albeit available, are often unaffordable for those who need them most. It is hoped that equitable differential pricing will be applied to Alzheimer's drugs.

Comparison of cholinesterase inhibitor utilization patterns and associated health care costs in Alzheimer's disease.

BACKGROUND: Sustained treatment with a cholinesterase inhibitor (ChEI) is used in the management of the symptoms of Alzheimer's disease (AD). However, the characteristic declines in learning and memory seen in AD may erode the patient's ability to adhere to medication regimens with or without caregiver support. OBJECTIVES: To examine differences by type of ChEI in (1) monthly prevalence of use, (2) nonpersistence, (3) switching from the index drug to another ChEI, (4) number of days on therapy, (5) medication possession ratio (MPR), and (6) an estimate of the relationship of these characteristics to total annual health care expenditures. METHODS: Data were from the MarketScan Medicare Supplemental and Coordination of Benefits 2001-2003 database, which comprised 1.47 million Medicare beneficiaries during this 3-year time period. Inclusion criteria were: (1) aged 65 years or older; (2) at least 1 claim with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 331.0 for AD in any of 15 diagnosis fields on outpatient claims or any of 2 diagnosis fields on inpatient claims at any time during 18 months of observation; (3) at least 1 pharmacy claim for donepezil, galantamine, or rivastigmine preceded by a 6-month period without a ChEI claim; and (4) at least 12 months of follow-up data, for a minimum 18 months continuous enrollment. Multivariate analyses, including logistic regression and exponential conditional mean models, tested for cohort differences in ChEI utilization, controlling for demographics, region of the country, type of insurer, and the Charlson Comorbidity Index (comorbid diagnoses). Using exponential conditional mean models, we also examined the relationship between utilization characteristics and all-cause (i.e., not specific to AD) health care expenditures for a 12-month period, including inpatient and outpatient (physician) care, laboratory and radiology services, emergency room (ER) use, prescription drugs, and long-term care services (e.g., nursing home care, home health visits) paid by Medicare or private insurance, but excluding long-term care services paid by Medicaid. Expenditure was defined as allowed charge (i.e., the total payment received by the service provider including plan and patient paid amounts.) RESULTS: More than 70% of the patients who received ChEI therapy and who otherwise met the inclusion criteria were excluded from this study due to the absence of at least 1 claim with a diagnosis for AD. Of the 3,177 patients included in the study, the index ChEI was donepezil for 62.8% of the patients (n=1,994); 17.2% received galantamine (n=546) and 20.1% received rivastigmine (n=637). The total number of days of index therapy dispensed was greater for those starting on donepezil (mean [median, SD] days=226 [263, 115]) compared with rivastigmine (206 [233, 120], P<0.001), but was not significantly different compared with galantamine (216 [250, 119], P=0.085). Monthly prevalence of use was similar for the 3 drugs until month 5 when a smaller proportion of rivastigmine patients had index medication on hand (65.9%) compared with 72.1% of donepezil patients (P=0.003) and 72.7% of galantamine patients (P=0.012). At 12 months, the likelihood of receiving the index ChEI was higher for donepezil (61.1%) than for either rivastigmine (50.1%, P<0.001) or galantamine (56.4%, P=0.048) and was higher for galantamine than for rivastigmine (P=0.030). The rate of switching for donepezil patients was significantly lower (14.5%) than the switch rate for rivastigmine patients (21.5%, P<0.001) and was similar to the switch rate for galantamine patients (15.0%, P=0.781 for donepezil vs. galantamine; P=0.004 for galantamine vs. rivastigmine). Rates of nonpersistence, measured as having at least 1 gap in therapy of 30 days or more during the 1-year follow-up, were 63.5% for donepezil, 63.7% for galantamine (P=0.933 for donepezil vs. galantamine), and 68.0% for rivastigmine (P=0.042 for donepezil vs. rivastigmine). MPRs and total days supply of any ChEI did not significantly differ among the 3 drugs. Results of multivariate models showed that, controlling for index ChEI drug, each additional month of ChEI treatment was associated with a reduction of 1% in total all-cause health care costs. The mean (SD) total all-cause 1-year health care costs for patients initiated on the 3 ChEIs were not significantly different: $12,112 ($16,437) for donepezil, $12,137 ($19,154) for galantamine (P=0.978), and $12,853 ($14,543) for rivastigmine (P=0.278). CONCLUSIONS: During the first year following initiation of ChEI therapy, patients initiated on donepezil had a greater days supply of the index medication than did patients initiated on rivastigmine. At 12 months following treatment initiation, the proportion of patients in therapy was higher for donepezil than for either rivastigmine or galantamine and was higher for galantamine than for rivastigmine. Patients treated with either donepezil or galantamine were less likely to switch from the index drug to another ChEI than were patients treated with rivastigmine. All-cause 1-year health care costs for patients initiated on the 3 ChEIs were not significantly different.

Impact of rivastigmine on caregiver burden associated with Alzheimer's disease in both informal care and nursing home settings.

Progressive deterioration in cognitive function and the ability to perform activities of daily living are the hallmarks of Alzheimer's disease (AD). As the disease progresses and behavioural/neuropsychiatric symptoms become more predominant, carers of AD patients themselves encounter a raft of physical, emotional, social and financial problems. Appropriate therapeutic management of AD patients, particularly their behavioural symptoms, may reduce the burden placed on family and professional caregivers. Preservation of cholinergic neurotransmission by cholinesterase inhibitors is the mainstay of pharmacological therapy for AD. Rivastigmine, a dual inhibitor of acetylcholinesterase and butyrylcholinesterase, has pharmacological properties that appear particularly favourable regarding the behavioural symptoms of AD. In addition to its beneficial effects on cognitive and global function, rivastigmine treatment in mild-to-moderate AD is associated with improvements in behavioural symptoms, a decreased requirement for antipsychotic drugs and delays in nursing home placement; reductions in caregiver burden, caregiver time and costs have also been reported. Rivastigmine treatment has also demonstrated improvements in behavioural symptoms and reductions in psychotropic medication usage in nursing home residents with moderate-to-severe AD, and may be associated with a reduction in professional caregiver burden. In summary, the positive effects of rivastigmine on functional and behavioural symptoms of AD help to reduce the time, stress and overall burden associated with caregiving, both in the informal home care and nursing home environments.

Economic evaluation of rivastigmine in patients with Parkinson's disease dementia.

BACKGROUND: The positive results of a randomised clinical trial of rivastigmine in patients with dementia associated with Parkinson's disease have been published recently. Patient-level healthcare utilisation data were also collected, and this report is the economic evaluation based on these data. OBJECTIVE: To determine the cost effectiveness of rivastigmine 3-12 mg/day in patients in whom mild to moderate dementia developed at least 2 years after they received a clinical diagnosis of Parkinson's disease. METHODS: A cost-effectiveness analysis was performed by applying Canadian and UK cost weights (year 2004 values) to healthcare utilisation data collected prospectively during a randomised, double-blind, multinational, 24-week trial of rivastigmine 3-12 mg/day (n = 362) versus placebo (n = 179). Patients were > or =50 years of age, had a Mini-Mental State Examination (MMSE) score of between 20 and 24 and had contact with a responsible caregiver at least 3 days a week.Quality-adjusted survival time, transformed from MMSE scores, was the measure of effectiveness. Caregiver costs included paid and unpaid time, and direct costs included concomitant medications, outpatient care, hospitalisations, long-term care and study medications. Analysis was conducted from a societal perspective with a time horizon of 24 weeks. RESULTS: Consistent with the improvement in clinical outcomes, there was an observed increase in quality-adjusted survival time in the rivastigmine arm of 2.81 quality-adjusted life-days (two-sided p-value 0.13 [90% CI -0.243, 5.86]). Using Canadian price weights, there was an observed increase in cost in the rivastigmine arm of Can 55.76 dollars(two-sided p-value 0.98 [90% CI -3431, 3543]), with a resulting incremental cost-effectiveness ratio of Can 7429 dollars per QALY. Using UK price weights, there was an observed decrease in cost in the rivastigmine arm of pound 26.18 (two-sided p-value 0.99 [90% CI -2407, 2355]). CONCLUSION: Although no between-treatment differences in cost were seen, the small sample size, highly variable cost distributions and short time horizon prevent us from making strong conclusions with regard to the effect of rivastigmine on total costs and, by inference, on cost effectiveness.

The clinical and cost-effectiveness of donepezil, rivastigmine, galantamine and memantine for Alzheimer's disease.

OBJECTIVES: To provide an update review of the best quality evidence for the clinical effectiveness and cost-effectiveness of donepezil, rivastigmine and galantamine for mild to moderately severe Alzheimer's disease (AD) and of memantine for moderately severe to severe AD. DATA SOURCES: Electronic databases, experts in the field and manufacturer submissions to the National Institute for Health and Clinical Excellence (NICE). REVIEW METHODS: A systematic review of the literature and an economic evaluation were undertaken. The quality of included randomised controlled trials (RCTs) was assessed using criteria developed by the NHS Centre for Reviews and Dissemination. An outline assessment of economic evaluations was undertaken using a standard checklist. The clinical and cost-effectiveness data were synthesised through a narrative review with full tabulation of the results of included studies. Where appropriate, meta-analysis of data was undertaken. RESULTS: For mild to moderately severe AD, the results of the study suggested that all three treatments were beneficial when assessed using cognitive outcome measures. Global outcome measures were positive for donepezil and rivastigmine, but mixed for galantamine. Results for measures of function were mixed for donepezil and rivastigmine, but positive for galantamine. Behaviour and mood measures were mixed for donepezil and galantamine, but showed no benefit for rivastigmine. For memantine, two published RCTs were included; in one of these trials the participants were already being treated with donepezil. The results suggest that memantine is beneficial when assessed using functional and global measurements. The effect of memantine on cognitive and behaviour and mood outcomes is, however, less clear. Literature on the cost-effectiveness of donepezil, rivastigmine and galantamine was dominated by industry-sponsored studies, and studies varied in methods and results. Of the three UK studies, two report donepezil as not cost-effective, whereas a third study reports an additional cost (1996 pounds sterling) of between 1200 pounds sterling and 7000 pounds sterling per year in a non-severe AD health state (concerns over these estimates are raised, suggesting that they may underestimate the true cost-effectiveness of donepezil). Cost-effectiveness analysis undertaken in this review suggests that donepezil treatment has a cost per quality-adjusted life-year (QALY) in excess of 80,000 pounds sterling, with donepezil treatment reducing the mean time spent in full-time care (delays progression of AD) by 1.42-1.59 months (over a 5-year period). From four published cost-effectiveness studies, two UK studies report additional costs associated with rivastigmine treatment. Cost-effectiveness analysis undertaken in the current review suggests that rivastigmine treatment has a cost per QALY in excess of 57,000 pounds sterling, with rivastigmine treatment reducing the mean time spent in full-time care (delays progression) by 1.43-1.63 months (over a 5-year period). From five published cost-effectiveness studies, one UK study reports a cost per QALY of 8693 pounds sterling for 16-mg galantamine treatment and 10,051 pounds sterling for 24-mg galantamine treatment (concerns raised suggest that this may underestimate the true cost-effectiveness of galantamine). Cost-effectiveness analysis undertaken in the present review suggests that galantamine treatment has a cost per QALY in excess of 68,000 pounds sterling, with galantamine reducing the time spent in full-time care (delays progression) by 1.42-1.73 months (over a 5-year period). From two published cost-effectiveness studies, one reports analysis for the UK, finding that memantine treatment results in cost savings and benefits in terms of delaying disease progression (concerns raised suggest that this may underestimate the true cost-effectiveness of memantine). In the current review, the cost-effectiveness of memantine has not been modelled separately, but where alternative parameter inputs on the cost structure and utility values have been used in a reanalysis using the industry model, the cost-effectiveness is reported at between 37,000 pounds sterling and 52,000 pounds sterling per QALY, with this alternative analysis still based on what is regarded as an optimistic or favourable effectiveness profile for memantine. CONCLUSIONS: Although results from the clinical effectiveness review suggest that these treatments may be beneficial, a number of issues need to be considered when assessing the results of the present review, such as the characteristics of the participants included in the individual trials, the outcome measures used, the length of study duration, the effects of attrition and the relationship between statistical significance and clinical significance. Many included trials were sponsored by industry. For donepezil, rivastigmine and galantamine, the cost savings associated with reducing the mean time spent in full-time care do not offset the cost of treatment sufficiently to bring estimated cost-effectiveness to levels generally considered acceptable by NHS policy makers. It is difficult to draw conclusions on the cost-effectiveness of memantine; it is suggested that further amendments to the potentially optimistic industry model (measure of effect) would offer higher cost per QALY estimates. Future research should include: information on the quality of the outcome measures used; development of quality of life instruments for patients and carers; studies assessing the effects of these interventions of durations longer than 12 months; comparisons of benefits between interventions; and research on the prediction of disease progression.