Postoperative cognitive dysfunction or impairment,
1 as a particular format and important component of the broader concept of perioperative neurocognitive disorder,
2 is a common complication of surgery and anesthesia. With large variations by age and surgery type, the incidence rates of postoperative cognitive dysfunction are most marked in older patients after cardiac surgery (16.0%-39.0% at 3 months),
3,4 whereas the rates after major noncardiac surgery (9.9%-12.7%) or surgery in younger patients (5.6% of those aged 40-59 years)
5,6 are lower. On the basis of small studies, a comparable incidence of postoperative cognitive impairment was reported among older Chinese surgery patients (10.3%-18.2%).
7,8 However, data from middle-aged Chinese adults with cognitive function measured up to 12 months after surgery are lacking. In addition to direct impairments in perception, thinking, and memory ability, cognitive impairment has been found to be associated with increased medical costs after surgery,
9 dismissal from work due to disabilities,
10 and even increased premature deaths.
6 Therefore, understanding the cognitive trajectories of surgery patients and identifying risk factors, particularly the modifiable ones that might contribute to postoperative cognitive deterioration, are crucial and have great clinical importance in terms of developing interventions for postoperative cognitive impairment prevention.