Associations of perioperative depression with sleep quality and physical activity levels in patients undergoing elective cardiac surgery: A prospective observational study.
Perioperative depression incidence peaked at postoperative day 7 (51%) in cardiac surgery patients, and was significantly associated with poorer sleep quality and lower physical activity levels throughout the perioperative period.
Key Findings
Results
The incidence of depression in cardiac surgery patients increased from preoperative levels, peaked at postoperative day 7, and remained elevated at postoperative day 30.
Preoperative depression incidence was 34% (95% CI: 0.27–0.46)
Depression peaked at postoperative day 7 at 51% (95% CI: 0.41–0.61)
Depression slightly decreased to 47% (95% CI: 0.38–0.57) at postoperative day 30
Depression was measured using the Patient Health Questionnaire-9 (PHQ-9)
100 consecutive elective cardiac surgery patients were prospectively enrolled
Results
Patients with preoperative depression had significantly higher Athens Insomnia Scale scores than nondepressed patients, indicating worse sleep quality.
Mean AIS score in depressed patients: 8.00 ± 1.39 vs. 5.32 ± 1.99 in nondepressed patients
Difference was statistically significant (p < 0.001)
Sleep quality was assessed using the Athens Insomnia Scale (AIS) questionnaire
Higher AIS scores indicate worse sleep quality
Results
Patients with preoperative depression had significantly lower physical activity levels than nondepressed patients.
Mean IPAQ-SF score in depressed patients: 948.32 ± 332.57 vs. 1461.65 ± 380.59 in nondepressed patients
Difference was statistically significant (p < 0.001)
Physical activity was assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF)
Preoperative depression scores were strongly correlated with sleep quality scores and moderately correlated with physical activity scores.
Spearman correlation between preoperative PHQ-9 and AIS scores: r = 0.64, p < 0.001 (strong positive correlation)
Spearman correlation between preoperative PHQ-9 and IPAQ-SF scores: r = -0.44, p < 0.001 (moderate negative correlation)
The negative correlation with IPAQ-SF indicates that higher depression scores were associated with lower physical activity
Results
Multiple factors were identified as risk factors for preoperative depression in cardiac surgery patients.
Risk factors identified through univariable and multivariable logistic regression included: age, employment status, education level, NYHA class, AIS scores, and IPAQ-SF scores
Both univariable and multivariable logistic regression analyses were used to detect risk factors
NYHA (New York Heart Association) class is a measure of heart failure severity
Results
Patients with better sleep quality and higher levels of physical activity were significantly less likely to experience depression during the perioperative period.
This finding was consistent across the perioperative period (preoperative, postoperative day 7, and postoperative day 30)
Data were collected preoperatively and at postoperative days 7 and 30
Independent-samples t tests and Spearman correlation analysis were used to explore these associations
The study was prospective and observational in design
What This Means
This research suggests that depression is very common in patients having heart surgery, affecting about one-third of patients before surgery and rising to more than half just one week after the operation. Even a month after surgery, nearly half of patients were still experiencing depression. The study followed 100 consecutive heart surgery patients and measured their depression levels, sleep quality, and physical activity at multiple time points before and after surgery.
The research found clear links between depression and two modifiable lifestyle factors: sleep quality and physical activity. Patients who were depressed slept significantly worse and were much less physically active compared to patients who were not depressed. These associations were present before surgery and persisted throughout the recovery period. Additional factors linked to a higher risk of preoperative depression included older age, unemployment, lower education level, and more severe heart disease symptoms.
This research suggests that screening for depression should be a routine part of care for cardiac surgery patients, starting before the operation. The findings also point to sleep quality and physical activity as potentially important targets — patients who sleep better and are more physically active appear to be at lower risk of perioperative depression. This could inform efforts to support patients' mental health both before and after heart surgery, though further research would be needed to determine whether improving sleep or increasing physical activity could directly reduce depression in this population.
Huang S, Chen Y, Wang Y, Xu S, Zhang J, Jiang T, et al.. (2026). Associations of perioperative depression with sleep quality and physical activity levels in patients undergoing elective cardiac surgery: A prospective observational study.. PloS one. https://doi.org/10.1371/journal.pone.0341232