Study population characteristics
A total of 1,290 patients who met the inclusion and exclusion criteria were included in the final analysis. The baseline demographic and clinical characteristics of the study population, stratified by depression status, are summarized in Table 1. Patients with depression were significantly older than those without depression (69.4 ± 6.9 vs. 67.9 ± 6.5 years, P < 0.001) and more likely to be female (47.7% vs. 41.6%, P = 0.023). Marital status was also significantly associated with depression. The prevalence of depression was highest among divorced or widowed patients (48.8%, 158/324), followed by unmarried (35.3%, 12/34), and lowest among married patients (33.5%, 312/932) (P < 0.001; see Supplementary Table 1). Depression was more common in those with lower educational attainment, smoking history, low physical activity, poor sleep quality, and comorbidities including hypertension, diabetes, chronic pain, and cognitive impairment. Among disease-specific factors, patients with digestive system tumors and liver cirrhosis had significantly higher rates of depression, whereas chronic gastritis was less common in the depression group.
Univariate analysis of factors associated with depression
Crude odds ratios derived from univariate logistic regression analysis (Table 2) revealed that several demographic, lifestyle, and clinical factors were associated with significantly higher odds of depression, including older age, female gender, divorced or widowed marital status, lower education level, smoking, low physical activity, poor sleep quality, hypertension, diabetes, cognitive impairment, chronic pain, digestive system tumors, liver cirrhosis, and anxiety symptoms.
Multivariable analysis of factors associated with depression
Multivariable logistic regression analysis further identified a number of these variables as independently associated with depression (Table 2). These included older age (adjusted OR: 1.05, 95% CI: 1.03–1.08, P < 0.001), female gender (adjusted OR: 1.32, 95% CI: 1.03–1.69, P = 0.028), divorced/widowed marital status (adjusted OR: 1.87, 95% CI: 1.37–2.54, P < 0.001), lower education level (adjusted OR: 2.86, 95% CI: 1.78–4.59, P < 0.001), smoking (adjusted OR: 1.45, 95% CI: 1.11–1.89, P = 0.006), low physical activity (adjusted OR: 2.24, 95% CI: 1.75–2.88, P < 0.001), and poor sleep quality (adjusted OR: 3.69, 95% CI: 2.81–4.83, P < 0.001). Comorbid conditions such as hypertension, diabetes, cognitive impairment, chronic pain, digestive system tumors, and liver cirrhosis also remained significantly associated with depression. Notably, anxiety symptoms were the strongest associated factor (adjusted OR: 4.76, 95% CI: 3.56–6.38, P < 0.001).
Clinical outcomes and subgroup analysis
Clinical outcomes stratified by depression status are presented in Table 3. Patients with depression had significantly longer hospital stays (14.2 ± 6.3 vs. 11.3 ± 5.2 days, P < 0.001). Hospitalization costs were also higher among patients with depression, with a median cost of ¥12,300 (approximately $1,809 or €1,577; IQR: ¥10,300–¥14,500) compared to ¥10,800 (approximately $1,588 or €1,385; IQR: ¥8,800–¥12,500) in those without depression (P < 0.001). They were less likely to achieve full recovery (48.5% vs. 72.8%, P < 0.001), and more likely to experience complications, including infections (29.5% vs. 20.8%, P < 0.001), gastrointestinal bleeding (19.1% vs. 11.6%, P < 0.001), and electrolyte imbalances (21.2% vs. 14.4%, P = 0.002). The 30-day readmission rate (23.7% vs. 10.9%, P < 0.001) and in-hospital mortality (6.2% vs. 3.0%, P = 0.007) were also significantly higher among patients with depression. Subgroup analysis of the association between anxiety symptoms and prolonged hospital stay (≥ 14 days), stratified by gender and age, is presented in Table 4. Anxiety symptoms were independently associated with prolonged hospitalization (adjusted OR: 1.78, 95% CI: 1.42–2.23, P < 0.001), with a stronger effect observed among female patients (adjusted OR: 2.11) and those aged ≥ 70 years (adjusted OR: 2.02). The highest risk was found in older female patients (adjusted OR: 2.35, 95% CI: 1.68–3.30, P < 0.001). In stratified analyses by disease type (see Supplementary Table 2), the associations between depression and prolonged hospital stay, complications, and 30-day readmission remained significant across most disease subgroups, though effect sizes varied. The strongest associations were observed among patients with digestive system tumors and liver cirrhosis, suggesting that psychological distress may have a more pronounced impact in patients with severe or life-threatening digestive conditions.
link