The investigators aim to establish a prospective database of perioperative elderly patients from multiple regions and centers. Collected data involves postoperative complications of the central nervous system, cardiovascular system, kidney, respiratory system, infection, pain, and other perioperative complications. Based on the database, the investigators intend to explore:

• The incidence and risk factors of perioperative morbidity and mortality in elderly patients;
• Perioperative risk assessment methods and early warning models for elderly patients;
• Practical, safe, and effective risk prevention and control system through subsequent studies.

As the population aging is speeding up, senile diseases have become a significant and severe public health problem, influencing national health. More than 20 million elderly patients undergo surgery each year in China, accounting for a quarter of the population who undergo surgery. Advanced age and comorbid diseases render the elderly at increased risk of postoperative morbidity and mortality. The incidence of postoperative complications is twice that of non-elderly patients, and mortality rates are five times higher than non-elderly patients. Thus, it is a significant challenge to safely and stably ensure the elderly are in an optimal perioperative period.

For the good of optimizing perioperative management, it is urgent to build a large-sample, multi-center database. Based on this database, the investigators can explore new risk assessment methods and establish a perioperative risk prediction model and early warning system suitable for elderly patients. It will help improve this group of patients' short- and long-term outcomes and thus reduce the economic burden of national health and medical resources.

In this context, establishing a clinical database including data for all perioperative elderly patients is of high interest. This database will allow the investigators to carry out clinical research on:

• Clinical, biological, and genetic factors predictive of perioperative complications and deaths;
• Systematic and individualized evaluation tools for elderly patients;
• Prognostic factors for improving short- and long-term outcomes. This is particularly significant for rare clinical evidence of perioperative elderly patients for which the current knowledge is scarce.

The database will also allow the investigators to develop or participate in multi-center trials, national or international, and facilitate the formation of perioperative data collection standards.

Inclusion Criteria:

• Geriatric surgical patients ≥65 years old, undergoing elective surgery with a planned overnight hospital stay following surgery.

Exclusion Criteria:

• Patients fully refused to participate in the study;
• Patients with severe dementia, language disorder, severe hearing or visual impairment, coma, and end-stage status were excluded;
• Patients whose surgeries were canceled;
• Patients accepted cardiac surgeries were excluded from the heart injury section;
• Patients accepted cardiac, neurosurgeries or were excluded from postoperative central nervous system and pain observation section;
• Patients refused to participate in neurocognitive, anxiety, depression, or pain questionnaire were excluded from relative assessment and measurement.

Hospital-based, elderly patients, perioperative/postoperative outcome/complications study