Depression and other psychological factors may be linked to the risk of postoperative confusion in older adults. This is shown in a new systematic review from Karolinska Institutet, published in the British Journal of Anaesthesia. The study summarizes results from more than 6,700 patients.
Older individuals undergoing surgery face an increased risk of developing cognitive complications, such as postoperative delirium. Delirium is characterised by sudden changes in attention and awareness, and can lead to longer hospital stays and reduced functioning. The new study analyzes 30 previously published works in which researchers examined whether preoperative psychological factors-such as depression, anxiety, stress, and personality traits-may influence these complications.
Depression most common
The review identified four groups of psychological factors. Depression was the most common and appeared in nearly all studies. In the statistical meta-analysis, no clear association between depression and delirium was observed, but when the researchers also included studies that could not be combined statistically, they still found evidence suggesting that psychological factors may play a role.
"Our results show that depression is the most consistently reported psychological risk factor, even though the pooled statistical analyses did not demonstrate a significant effect," says Anahita Amirpour, PhD at the Department of Neurobiology, Care Sciences and Society .
"At the same time, we saw that anxiety, stress, and personality traits may also play a role, although the research base there is more limited."
Postoperative delirium
In total, the study included 6,714 patients from 16 different countries. Postoperative delirium was the most common outcome measure and occurred in between 9 and 55 percent of patients, depending on the study. Very few studies examined other cognitive complications, such as long-term effects on memory and attention.
The researchers emphasize that the results should be interpreted with caution. Many of the included studies varied greatly in how they measured both psychological factors and cognitive outcomes, and only two studies examined time periods extending beyond the immediate postoperative phase.
The study was conducted by researchers at Karolinska Institutet and Danderyd Hospital, with collaborations from several international research groups. The work was funded by the Strategic Research Area Health Care Science (SFO‑V) and Karolinska Institutet. The researchers report no conflicts of interest.
