Study on the Health Economic Burden of Alzheimer's Disease in China

Inclusion Criteria: 1. Criteria for selection of centers The study center sample relied on the 192 cognitive centers selected for the 2022 National Health and Health Commission Capacity Building and Continuing Education for Cognitive Impairment Disease Specialty Capacity Building Program. The study covered all 31 provincial administrative units in mainland China, divided according to east, center, and west: East: Hebei, Beijing, Tianjin, Shandong, Jiangsu, Shanghai, Zhejiang, Fujian, Guangdong, Hainan, Heilongjiang, Jilin, and Liaoning; Central: Henan, Hubei, Hunan, Anhui, Jiangxi, Shanxi; West: Chongqing, Sichuan, Yunnan, Guizhou, Tibet, Shaanxi, Gansu, Qinghai, Xinjiang, Ningxia, Inner Mongolia, Guangxi. 2. amnestic mild cognitive impairment (aMCI) inclusion criteria (all of the following conditions must be met at the same time) and exclusion criteria: Inclusion criteria: 1. Compliance with Peterson's aMCI diagnostic criteria National Institute on Aging and Alzheimer's Disease Association (NIA-AA) aMCI diagnostic criteria in 2004 \[7\]. 2. Clinical Dementia Rating (CDR) of 0.5. 3. Mini-Mental State Examination (MMSE): ≥17 points on MMSE for those with 0 years of education, ≥20 points for those with less than 7 years, and ≥24 points for those with greater than or equal to 7 years. 4. Memory loss is prominent and may also be accompanied by impairment of other cognitive domains. 5. Insidious onset and slow progression. 6. Not reaching the level of dementia. 3. Alzheimer's disease inclusion criteria (must meet all of the following conditions at the same time) and exclusion criteria: Inclusion Criteria: 1. Meets the core clinical criteria for probable AD dementia in the 2011 NIA-AA Revised Diagnostic Criteria for AD. \[7\] 2. Can be categorized as having mild, moderate, or severe Alzheimer's disease. 1. Mild: progressive cognitive impairment affecting multiple domains and psychobehavioral deficits; significant impact on daily life, primarily impairing instrumental activities, no longer fully independent, occasionally requiring assistance; or a CDR score of 1.0 2. Moderate: progressive cognitive impairment and psychobehavioral changes; extensive impact on daily life, partial impairment of basic functioning, inability to live independently, frequent need for assistance; or CDR 2.0 score 3. Severe: progressive cognitive impairment and psychobehavioral changes, may not be able to conduct clinical interviews; severe impact on daily life, impairment of basic activities including self-care, total dependence on help; or CDR 3.0 points 3. CDR greater than 0.5 points. 4. MMSE: \<17 points for those with 0 years of education, \<20 points for those with less than 7 years, and \<24 points for those with greater than or equal to 7 years. 5. Subject has good audiovisual and speech functions or can complete a neuropsychological examination with correction. 6. The subject and the informant can complete relevant examinations and follow-up visits. 7. The subject or his/her authorized delegate signs the informed consent form. 4. Inclusion/exclusion criteria for Alzheimer's disease multiple chronic co-morbidities (aMCI) need to be met in addition to meeting the aMCI inclusion and exclusion criteria or Alzheimer's disease inclusion and exclusion criteria: Inclusion criteria: 1. Age not less than 60 years 2. Normal or corrected vision and hearing 3. able to provide informed consent signed by him/herself or a legal guardian 4. Newly diagnosed or previously diagnosed with a co-morbid condition other than aMCI or Alzheimer's disease. Exclusion Criteria: 2\. amnestic mild cognitive impairment (aMCI) exclusion criteria: (excluded if any of the following conditions are met): 1. Those with a history of stroke with focal neurologic signs and an imaging presentation consistent with cerebral small vessel disease manifestations (Fazekas score ≥ 2). 2. Presence of mental and neurodevelopmental delays. 3. Presence of other conditions known to cause cognitive impairment. 4. Presence of a disease that prevents cooperation in completing the cognitive examination. 5. Refusal to sign the informed consent form at baseline. 3. Alzheimer's Disease Exclusion Criteria: (Excluded if any of the following criteria are met): 1\) Presence of mental and neurodevelopmental delays. 2) Disease that prevents cooperation in completing the cognitive examination. 3) Refusal to sign the informed consent form at baseline. 4. Inclusion/exclusion criteria for Alzheimer's disease multiple chronic co-morbidities (aMCI) Required on top of meeting aMCI inclusion and exclusion criteria or Alzheimer's disease inclusion and exclusion criteria: Exclusion Criteria (excluded if any of the following conditions are met): 1. Poor compliance or mental and neurodevelopmental delays. 2. Illness that prevents the completion of the cognitive examination. 3. Refusal to sign an informed consent form at baseline. 4. Severe circulatory, respiratory, urinary, gastrointestinal, hematopoietic diseases (e.g., unstable angina, uncontrolled asthma, active gastric bleeding, etc.) and cancer. 5. No reliably informed person. 6. Patient has a history of alcohol or drug abuse.