The Alzheimer's disease Burden in China (ABC) study: protocol for a nationwide multicentre cross-sectional and prospective cohort study

IntroductionAlzheimers disease (AD) is imposing an increasing public health and socioeconomic burden. In China, rapid population ageing is sharply increasing disease burden. Previous studies have shown that AD-related costs are mainly driven by long-term informal care. However, evidence in China remains limited by an incomplete cost framework, and insufficient consideration of caregivers burden and indirect costs. Notably, the National Dementia Action Plan (2024-2030), issued by the Chinese government, marks a major shift to early detection and comprehensive care of AD, highlighting the urgent need for nationally representative economic evidence to support policy implementation. This study aims to evaluate the economic burden and quality of life of AD patients and their caregivers in mainland China, and is the first nationwide study to include individuals with amnestic mild cognitive impairment (aMCI), providing foundational data for future health technology assessment (HTA) of early AD interventions. Methods and analysisBaseline characteristics will be presented and compared using t-tests or chi-square tests. Economic burden will be estimated by calculating the per capita cost and weighted national total based on provincial numbers of AD patients. Indirect costs will be assessed using locally adapted replacement cost approach and forgone wages approach. The analysis will be stratified by disease severity and age. Future burden will be projected by linking data from China Statistical Yearbook 2025 and the United Nations World Population Prospects 2024. Unmet care needs, AD-related catastrophic health expenditure (CHE), and AD dependency ratio (ADDR) will also be assessed. Ethics and disseminationEthics approval was obtained from the Ethics Committee of Xuanwu Hospital, Capital Medical University. The study has been registered at ClinicalTrials.gov and the Chinese Clinical Trial Registry (ChiCTR). The results from this study will be actively disseminated through research articles and conference presentations. Trial registration numberNCT05995418; ChiCTR2300074723. Strengths and limitations of this studyO_LIThis study employs a two-stage probability sampling design across 602 cognitive centres in 31 provinces, ensuring strong national representativeness of the Chinese population. C_LIO_LIIt is the first national health economics study to prospectively include patients with amnestic mild cognitive impairment (aMCI), addressing a critical evidence gap in the early stage of disease and providing data for future evaluation of the cost-effectiveness of early screening and interventions. C_LIO_LIThe integration of clinical characteristics, economic burden, and quality of life scales provides a multidimensional framework for future policy evaluations and health technology assessment (HTA). C_LIO_LIThe calculation of indirect costs relies heavily on caregivers self-reported data regarding care time and missed work, which may introduce recall bias. C_LIO_LIThe use of a nested subsample for the 12-month follow-up may introduce loss-to-follow-up bias, although appropriate statistical weighting techniques will be applied to mitigate this. C_LI