ABSTRACT
BACKGROUND: Given the evolution of early diagnosis guidelines and future disease-modifying therapies, estimating the prevalence of Alzheimer's disease (AD) at early stages is key. OBJECTIVE: To estimate the number of people living with mild cognitive impairment (MCI) due to AD and mild AD dementia in France in 2022 that could be eligible to future AD therapies. METHODS: A step-by-step approach was defined based on disease stages definition and clinical practice. In line with AD guidelines, amyloid-positive profile is considered in our estimates to enhance the diagnosis accuracy of early stages of AD. Age-stratified prevalence from French cohort and international pooled analyses were identified to feed the different steps. To consider uncertainty around mean prevalence values, low and high scenarii based on the lower and upper bounds of the 95% confidence interval were conducted. RESULTS: We estimated that 2.5 (low scenario: 1.7 - high scenario: 3.6) million people suffer from mild cognitive impairment in France in 2022 among whom 1.65 (low: 1.5 - high: 1.8) million people meet the criteria for mild cognitive impairment due to AD i.e., with amyloid positive profile. The expected number of clinical AD dementia is estimated at 925,886 people. Among those, 379,278 people suffer from mild AD dementia based on clinical diagnosis, including 311,043 (low: 289,174 - high: 328,332) cases with amyloid positive profile. CONCLUSION: MCI due to AD, and mild dementia stages are potentially of high prevalence. Population-based studies are needed to confirm those estimates.
Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Dementia , Humans , Alzheimer Disease/diagnosis , Alzheimer Disease/epidemiology , Alzheimer Disease/psychology , Prevalence , Dementia/diagnosis , Cognitive Dysfunction/diagnosis , AmyloidABSTRACT
INTRODUCTION: The course of schizophrenia can vary widely, and patients experience remission phases alternating with relapse episodes, which generally lead to hospitalisation and have a significant impact on the burden of disease. The prevalence of schizophrenia in France is estimated to be approximately 600,000 people, with an incidence of 10,000 new patients per year. Patients with schizophrenia represent the largest group of hospitalised patients in French public institutions and specialised centres, and the French authorities recognise that the management of schizophrenia is a major public health concern. The Haute Autorité de Santé (HAS) and most of the evidence-based guidelines for the maintenance treatment of schizophrenia recommend long-acting injectable (LAI) antipsychotics to be used predominantly in the prevention of relapse for non-compliant patients; however, in clinical practice, the use of LAIs remains low. OBJECTIVE: This analysis aimed to estimate and to compare the cost-effectiveness of the most common antipsychotic strategies in France in the management of schizophrenia. METHODS: A Markov model was developed to simulate the progression of a cohort of patients with schizophrenia through four health states (stable treated, stable non-treated, relapse and death) and considered up to three lines of treatment to account for changes in treatment management. Antipsychotics including aripiprazole LAI (ALAI), olanzapine LAI (OLAI), paliperidone LAI (PLAI), risperidone LAI (RLAI), haloperidol decanoate (HD) and oral olanzapine (OO) were compared in terms of costs and clinical outcomes. Thus, costs, quality-adjusted life-years (QALYs) and number of relapses were assessed over five years based on three-month cycles from a French health insurance perspective with a discount rate of 4 %. Patients were considered to be stabilised after clinical decompensation and would enter the model at an initiation phase, followed by a prevention of relapse phase if successful. Data (e.g. relapse or discontinuation rates) for the initiation phase came from randomised clinical trials, whereas relapse rates in the prevention phase were derived from hospitalisation risks based on French real-life data in order to capture adherence effects. Safety and utility data were derived from international publications. Additionally costs were retrieved from French health insurance databases and publications. Robustness of results was assessed through deterministic and probabilistic sensitivity analyses. RESULTS: First and second generations of LAIs were found to have similar costs over five years; i.e. approximately 55,000, except for PLAI which was associated with a discounted cost of 50,880. Oral antipsychotics were found to be less costly (i.e. OO cost 50,379 after five years) but associated with a lower number of QALYs gained and relapse avoided. PLAI and RLAI were associated with the greatest number of QALYs gained; i.e. PLAI dominated ALAI, OLAI and HD and was associated with an incremental costs-effectiveness ratio (ICER) of 2411 per QALY gained versus OO. Finally, PLAI and OLAI were associated with the lowest number of relapses; i.e. PLAI dominated RLAI, ALAI and HLAI and was associated with an ICER of 1782 per avoided relapse compared to OO. OO and HD were found to have led to the highest number of relapses. CONCLUSION: This analysis, to the best of our knowledge, is the first of its kind to assess the cost-effectiveness of antipsychotics based on French observational data. PLAI was associated with the highest probability of being the optimal treatment from the French health insurance perspective.
