Adverse events related to colonoscopy: Global trends and future challenges

Table 6 Summary of major risk factors for perforation and bleeding related to colonoscopy from recent studies with sample sizes > 50,000 cases (%)

Ref.	Risk factors for perforation	Risk factors for bleeding
Rabeneck et al[77]	Comorbidity score ≥ 3 (OR: 3.73, 95%CI: 1.59-8.77), Polypectomy (OR: 2.96, 95%CI: 2.31-3.80), Old age (OR: 2.06, 95%CI: 1.79-2.37)	Polypectomy (OR: 10.32, 95%CI: 6.52-16.34), Old age (OR: 1.61, 95%CI: 1.20-2.16)
Crispin et al[46]	Polyp size: 0.5-1 cm (OR: 11.93, 95%CI: 3.02-47.13), Polyp size: 1-3 cm (OR: 28.12, 95%CI: 7.82-101.09), Polyp size > 3 cm (OR: 31.49, 95%CI: 6.37-155.66), Polypectomy (OR: 2.27, 95%CI: 1.39-3.70), Old age (OR: 1.00, 95%CI: 1.00-1.00)	Polyp size: 0.5-1 cm (OR: 5.25, 95%CI: 3.42-8.06), Polyp size: 1-3 cm (OR: 16.84, 95%CI: 11.14-25.46), Polyp size > 3 cm (OR: 27.52, 95%CI: 17.20-44.05), Polypectomy (OR: 60.21, 95%CI: 35.90-100.99), Biopsy (OR: 8.88, 95%CI: 5.06-15.59), Colonoscopy in patients with symptoms (OR: 1.31, 95%CI: 1.04-1.67), Pedunculated polyp (OR: 1.55, 95%CI: 1.26-1.90), Number of polyps: 2-4 (OR: 1.26, 95%CI: 1.06-1.50), Old age (OR: 1.00, 95%CI: 1.00-1.00)
Arora et al[72]	Colonoscopy indication (obstruction) (OR: 5.09, 95%CI: 3.17-8.20), Colonoscopy procedure1 (OR: 6.12, 95%CI: 3.16-11.83), Comorbidity score ≥ 2 (OR: 1.52, 95%CI: 1.12-2.06), Old age (OR: 1.01, 95%CI: 1.00-1.02)	-
Pox et al[30]	Polypectomy	Polypectomy
Hamdani et al[73]	Colonoscopy indication: Crohn’s disease (OR: 5.16, 95%CI: 1.79-14.88), Colonoscopy indication: abdominal pain (OR: 5.79, 95%CI: 2.64-12.74), Colonoscopy indication : Diagnostic (OR: 15.33, 95%CI: 7.79-30.18), Inpatient (OR: 11.05, 95%CI: 5.14-23.75), ICU patient (OR: 5.83, 95%CI: 2.80-12.14), Low albumin (≤ 4.0) (OR: 3.58, 95%CI: 1.72-7.47), Old age (OR: 1.03, 95%CI: 1.01-1.05)	-
Samalavicius et al[79]	Low-volume practice center	-
Blotière et al[29]	Age: 60-69 (OR: 2.91, 95%CI: 1.66-5.10), Age: 70-79 (OR: 5.38, 95%CI: 3.08-9.40), Age ≥ 80 (OR: 7.51, 95%CI: 4.20-13.45), Emergency colonoscopy (OR: 4.63, 95%CI: 3.52-6.10), Polyp size ≥ 1 cm (OR: 2.72, 95%CI: 2.05-3.60)	Age: 60-69 (OR: 1.70, 95%CI: 1.18-2.43), Age: 70-79 (OR: 2.55, 95%CI: 1.77-3.66), Age ≥ 80 (OR: 3.23, 95%CI: 2.21-4.73), Emergency colonoscopy (OR: 5.99, 95%CI: 5.01-7.15), Polyp size ≥ 1 cm (OR: 5.12, 95%CI: 4.33-6.04), Chronic disease (OR: 1.76, 95%CI: 1.53-2.02), Gender (male) (OR: 1.64, 95%CI: 1.43-1.87)
Rutter et al[52]	Polypectomy, Location of polyp (cecum) (OR: 5.60, 95%CI: 1.37-22.83)	Polypectomy, Location of polyp (cecum) (OR: 13.50, 95%CI: 3.93-46.42), Increasing polyp size (OR: 4.92, 95%CI: 2.84-8.51)
Bielawska et al[16]	Age: 60-74 (OR: 2.69, 95%CI: 1.83–3.98), Age ≥ 75 (OR: 5.63, 95%CI: 3.73-8.49), Gender (female) (OR: 2.00, 95%CI: 1.43-2.80), ASA class III (OR: 2.14, 95%CI: 1.22-3.75), ASA class IV/V (OR: 7.20, 95%CI: 2.41-21.50), Hospital setting: university (OR: 2.83, 95%CI: 1.85-4.31), Hospital setting: VA/military (OR: 3.74, 95%CI: 2.37-5.89), Any therapy (OR: 3.93, 95%CI: 2.05-7.56), Polyp size ≥ 1 cm (OR: 4.14, 95%CI: 2.58-6.65), Endoscopy specialty: surgery or unknown (OR: 2.00, 95%CI: 1.30-3.08)	-

¹Colonoscopy procedure includes treatment of foreign-body, submucosal injection, hemostasis, endoscopic ultrasound, transmural or intramural aspiration or biopsy.