***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Alzheimer 's disease ( AD ) is estimated to affect up to 11 % of those aged > or = 65 years in the United States , and the number of patients with AD is predicted to increase over the next few decades as the population ages . The substantial social and economic burden associated with AD is well established , with the cost of management increasing as the disease progresses . OBJECTIVE The aim of this study was to evaluate the economic impact of galantamine 16 and 24 mg/d relative to no pharmacologic treatment in the management of mild to moderate AD in the United States based on the concept of need for full-time care ( FTC ) . METHODS Calculations were made using the Assessment of Health Economics in Alzheimer 's Disease model , which applies predictive equations to estimate the need for FTC and the associated costs . The predictive equations were developed from longitudinal data on patients with AD . Inputs to the equations were derived by analyzing the data from 2 r and omized , placebo-controlled , galantamine clinical trials . Re source use ( from a payer perspective ) was estimated from US clinical trial data , and costs were estimated from several US data bases . Analyses were carried out over 10 years , and costs and benefits were discounted at 3 % . RESULTS In the base case , 3.9 to 4.6 patients need to start treatment with galantamine to avoid 1 year of FTC , depending on dose . Treated patients spent 7 % to 8 % more time pre-FTC and 12 % to 14 % less time requiring FTC , result ing in savings of 2408 to 3601 US dollars . Time horizons below 3 years , very high discontinuation rates , or increased survival with galantamine reversed the savings . Conversely , limiting treatment to responders delayed FTC by 6 to 7 months , with savings of approximately 9097 to 11,578 US dollars . CONCLUSIONS These results suggest that use of galantamine in patients with AD in the United States could reduce the use of costly re sources such as formal home care and nursing homes , leading to cost savings over time To investigate whether Galantamine significantly improves the core symptoms of Alzheimer 's disease ( AD ) This 12-week , multinational study compared the tolerability and cognitive effects of donepezil ( up to 10 mg once daily ) and rivastigmine ( up to 6 mg twice daily ) in 111 patients with mild to moderate Alzheimer 's disease . Both medications were administered open label according to recommended dosing regimens from the respective product labelling available during the conduct of the study . More patients in the donepezil group ( 89.3 % ) completed the study compared with the rivastigmine group ( 69.1 % ; p=0.009 ) , and 10.7 % of the donepezil group and 21.8 % of the rivastigmine group discontinued due to adverse events ( AEs ) ; 87.5 % of donepezil-treated patients and 47.3 % of rivastigmine-treated patients remained on the maximum approved dose of each drug at the last study visit . Both groups showed comparable improvements on the ADAS-cog administered by raters blind to study medication at weeks 4 and 12 . Thus , using the recommended dosing schedules , donepezil was better tolerated with fewer discontinuations due to AEs , and both agents improved cognition to a similar extent Objective : To demonstrate the use of cost-effectiveness analysis to assess the economic impact of  donepezil  in the treatment of mild or moderate AD . Background : Cost-effectiveness analyses show the relationship between re sources used ( costs ) and health benefits achieved ( effects ) for an intervention compared with an alternative strategy . Methods : We developed a model to estimate the incremental cost-effectiveness of donepezil compared with no treatment . We determined costs per quality -adjusted life-years gained , a measurement that enhances the comparability of diverse studies . The model projects the progression of AD patients into more severe disease stages and into nursing homes . Data from a r and omized clinical trial of  donepezil  were used to assess the drug ’s impact on the 6-week probabilities of progression . Data on the costs and health-related quality of life associated with different disease stages and setting s were taken from published estimates and our companion cross-sectional study , respectively . Results : Donepezil costs are partially offset by a reduction in the costs of care due to enhancement in cognitive functioning and the delay to more costly disease stages and setting s. The magnitude of this cost offset and of the effect of donepezil on health-related quality of life depends on the model ’s assumptions about the duration of the drug effect , where controlled data are lacking . If the drug effect exceeds 2 years , the model predicts that for mild AD the drug would pay for itself in terms of cost offsets . Conclusions : The results of the cost-effectiveness model presented here suggest that donepezil may be cost-effective but additional controlled data on long-term drug efficacy are needed OBJECTIVE To estimate per-patient potential cost savings using rivastigmine in the treatment of Alzheimer 's disease ( AD ) in Canada . BACKGROUND In recent years , new members of a class of pharmaceuticals known as cholinesterase inhibitors have been introduced for the treatment of patients with AD . Two recent studies conducted in the United Kingdom and the United States estimated potential cost savings from the new cholinesterase inhibitor rivastigmine . The present study combined the disease-progression model used in those 2 studies with Canadian costs to estimate per-patient potential savings result ing from the treatment of AD in Canada . METHODS Efficacy data from 2 pivotal , phase III clinical trials of rivastigmine were used in a hazard model of disease progression to estimate long-term differences in cognitive functioning between patients receiving rivastigmine and patients receiving no treatment . We used the Mini-Mental State Examination ( MMSE ) score as our measure of disease progression . We also used Canadian costs of AD care , estimated as a function of MMSE score , to estimate cost savings experienced by treated patients compared with patients receiving no treatment . All costs and cost savings are presented in 1997 Canadian dollars . We used a societal perspective in this analysis . RESULTS Rivastigmine was estimated to delay the transition to more severe stages of AD by up to 188 days for patients with mild AD after 2 years of treatment . For patients with mild-to-moderate and moderate disease , this delay was estimated to be 106 and 44 days , respectively . For patients with the mild stage of AD , estimated average daily cost savings ( excluding the cost of rivastigmine ) ranged from Can $ 0.45 per patient per day at 6 months to Can $ 6.44 per patient per day after 2 years of treatment . For all patients , these estimated average daily cost savings ranged from a low of Can $ 0.71 per patient per day after 6 months of treatment to a high of Can $ 4.93 per patient per day after 2 years . CONCLUSION On average , treatment with rivastigmine yields savings in the direct cost of caring for AD patients that exceed the cost of the drug after 2 years of treatment 
    Output:
    
The key determinants of cost effectiveness were the effectiveness of treatment , the mean treatment cost and the cost savings associated with an expected delay in disease progression .
Conclusions : Results presented in this paper suggest that the use of cholinesterase inhibitors may not be a cost-effective use of NHS re sources .
Guidance from the National Institute for Health and Clinical Effectiveness ( NICE ) in the UK on their judgements surrounding the acceptability of technologies as an effective use of re sources , indicates there would need to be special reasons for accepting cholinesterase inhibitors as a cost-effective use of NHS re sources