Table 2.

Results and meta-analyses of observational studies on the effects of colonoscopy on CRC. Values are relative risks (95% confidence intervals) unless stated otherwise

Study	Year	Intervention	Incidence	Mortality
Ko et al. 57	2019	Screening	0.41 (0.39-0.43)	NR
Lee et al. 35	2019	Screening	0.54 (0.31-0.94)	0.12 (0.02-0.82)
Doubeni et al. 27	2018	Screening	NR	0.33 (0.21-0.52)
Niikura et al. 36	2017	Various*	0.50 (0.34-0.68)	0.08 (0.02-0.17)
Wang et al. 37	2016	Screening	0.42 (0.28-0.65)	NR
Stock et al. 38	2016	Screening	NR	0.36 (0.33-0.38)
Ananthakrishnan et al. 39	2015	Screening	0.65 (0.45-0.93)	0.34 (0.12-0.95)
Kahi et al. 40	2014	Screening/diagnostic	0.57 (0.47-0.70)	NR
Morois et al. 41	2014	Screening	0.56 (0.47-0.68)	NR
Brenner et al. 42	2014	Screening	0.11 (0.08-0.15)	NR
Doubeni et al. 43	2013	Various*	0.29 (0.15-0.58)	NR
Wang et al. 44	2013	Screening/diagnostic	0.34 (0.25-0.46)	NR
Nishihara et al. 8	2013	Screening	NR	0.32 (0.24-0.45)
Eldridge et al. 45	2013	Screening	NR	0.41 (0.30-0.55)
Manser et al. 46	2012	Screening	0.31 (0.16-0.59)	0.12 (0.01-0.93)
Jacob et al. 47	2012	Screening/diagnostic	0.52 (0.34-0.76)	0.19 (0.07-0.47)
Baxter et al. 25	2012	Screening/diagnostic	NR	0.40 (0.37-0.43)
Schoen et al. 10	2012	Screening	0.79 (0.72-0.85)	NR
Mulder et al. 48	2010	diagnostic	0.56 (0.33-0.94)	NR
Kahi et al. 11	2009	Screening	0.52 (0.22-0.82)	NR
Blom et al. 49	2008	Screening	0.50 (0.20-1.30)	NR
Cotterchio et al. 50	2005	Various*	0.52 (0.34-0.80)	NR
Newcomb et al. 51	2003	Screening	0.24 (0.17-0.33)	NR
Slattery et al. 52	2000	Screening	NR	NR
Scheitel et al. 53	1999	Screening	NR	0.89 (0.47-1.66)
Müller et al. 24	1995	diagnostic	NR	0.45 (0.30-0.66)
Müller et al. 54	1995	diagnostic	0.53 (0.41-0.69)	NR
Selby et al. 55	1992	Screening	NR	0.41 (0.25-0.69)
Newcomb et al. 56	1992	Screening	NR	0.21 (0.08-0.52)

*Various types analysed separately; NR, not reported.