Delivering a high-quality colonoscopy service fit for the 21st century

Table 1 Summary of literature reviewed

Ref.	Study format	Level of evidence1
Benefits and risks of colonoscopy
Bretthauer et al[6], 2022	Randomized controlled trial	I
Lin et al[7], 2021	Systematic review	II
Ryhlander et al[6], 2022	Cross-sectional study	III
Sajid et al[9], 2015	Systematic review	II
Hafner et al[10], 2015	Systematic review	II
Quality assurance, training, and human resources
Rex et al[11], 2015	Systematic review	II
Sawhney et al[12], 2008	Cross-sectional study	III
Chung et al[13], 2010	Cross-sectional study	III
Haycock et al[14], 2010	Randomized controlled trial	II
Khan et al[15], 2012	Systematic review	II
Barton et al[16], 2012	Cross-sectional study	III
Sedlack et al[17], 2011	Observational study	V
Gupta et al[18], 2012	Observational study	V
Hitchins et al[19], 2018	Review	V
Endoscopic assessment and risk stratification of premalignant polyps, with tattoo
Kaltenbach et al[20], 2022	Guideline	V
The Paris Endoscopic Classification of Superficial Neoplastic Lesions, 2003	Retrospective case series	V
Komeda et al[22], 2017	Retrospective case series	V
Pohl et al[23], 2018	Commentary	V
Kudo et al[24], 1996	Case series	V
Hayashi et al[25], 2013	Case series	V
Hewett et al[26], 2012	Case series	V
Kitajima et al[27], 2004	Case series	V
Ishigaki et al[28], 2020	Retrospective case series	V
Nivatvongs et al[29], 1991	Retrospective case series	V
Ueno et al[30], 2004	Retrospective case series	V
Cooper et al[31], 1995	Retrospective case series	V
Haggitt et al[32], 1985	Retrospective case series	V
Kikuchi et al[33], 1995	Case series	V
Heafner et al[34], 2014	Review	V
Yang et al[35], 2017	Review	V
Artificial intelligence
Repici et al[36], 2022	Randomized controlled trial	I
Hassan et al[38], 2020	Retrospective case series	V
Bowel preparation
Lai et al[39], 2009	Case series	V
Mahmood et al[40], 2018	Systematic review	II
Russmann et al[41], 2007	Retrospective cohort study	IV
Parikh et al[42], 2011	Review	V
Spada et al[43], 2017	Randomized controlled trial	I
Chen et al[44], 2020	Meta-analysis	II
Alternatives to colonoscopy
Lin et al[7], 2021	Systematic review	II
Rex et al[45], 2015	Case series	V

¹Adopted from “Level of evidence hierarchy” published by Elsevier Author Services.