Preoperative anaemia was independently associated with an increased risk of severe Clavien-Dindo grade IV-V complications compared to non-anaemic patients (7.4% vs 2.6%; adjusted OR 1.76).
Cohort (n=1,472)
No
Does low preoperative haemoglobin increase the risk of severe postoperative complications in patients undergoing colorectal cancer surgery?
Low preoperative haemoglobin is an independent risk factor for severe postoperative complications, particularly non-surgical events, after colorectal cancer surgery.
Effect estimate: OR 1.76 (95% CI 1.01-3.05)
Absolute Event Rate: 7.4% vs 2.6%
p-value: p=<0.001
BACKGROUND: Preoperative anaemia is common in patients undergoing colorectal cancer surgery, but the association between preoperative haemoglobin (Hb) and postoperative morbidity remains unclear. METHODS: This retrospective cohort study included all 2,374 patients who underwent elective colorectal segmental resection for colorectal cancer at Oulu University Hospital between 2014 and 2024. After exclusions for missing Hb data (n=49), procedures other than primary curative resection (n=735), missing complication data (n=117), and age under 18 years (n=1), 1,472 patients were analysed. Receiver operating characteristic analysis was used to determine the optimal Hb cut-off, and logistic regression was used to identify factors associated with Clavien-Dindo classification (CDC) grade IV-V complications. RESULTS: Preoperative anaemia was present in 444/859 (51.7%) men and 208/613 (33.9%) women. Overall, 758/1,472 (51.5%) patients developed a postoperative complication. Compared with non-anaemic patients, anaemic patients had higher rates of CDC grade IV-V complications (7.4% vs 2.6%, p<0.001) and non-surgical complications (31.4% vs 20.4%, p<0.001). The optimal Hb cut-off for CDC grade IV-V complications was 117.5 g/L. Low Hb was associated with severe complications in univariable (OR 3.02, 95% CI 1.79-5.10) and multivariable analyses (OR 1.76, 95% CI 1.01-3.05). CONCLUSIONS: Low preoperative Hb is an independent risk factor for severe postoperative complications, particularly non-surgical events, after colorectal cancer surgery. Data-driven Hb thresholds may improve preoperative risk stratification.
Peroja et al. (2026) conducted a cohort in Colorectal cancer (n=1,472). Preoperative anaemia (low haemoglobin) vs. Normal preoperative haemoglobin was evaluated on Clavien-Dindo classification (CDC) grade IV-V complications (OR 1.76, 95% CI 1.01-3.05, p=<0.001). Preoperative anaemia was independently associated with an increased risk of severe Clavien-Dindo grade IV-V complications compared to non-anaemic patients (7.4% vs 2.6%; adjusted OR 1.76).