Table 3.

Sensitivity analysis of different timing of aspirin use in relation to CRC mortality

Timinga	Study	RR (95% CI)
Timing 1
CRC-specific mortality	Gray RT et al. 2017 (21) Tsoi KK et al. 2018 (48) Ventura L et al. 2018 (49)	0.61 (0.53 to 0.69) 0.70 (0.56 to 0.89) 0.59 (0.56 to 0.62)
All-cause mortality	Chae YK et al. 2013 (51) Ng K et al. 2015 (37) Zanders MM et al. 2015 (39) Gray RT et al. 2017 (21) Tsoi KK et al. 2018 (48) Ventura L et al. 2018 (49)	1.08 (0.92 to 1.28) 1.14 (0.97 to 1.35) 1.13 (0.95 to 1.35) 1.18 (1.00 to 1.39) 0.97 (0.76 to 1.24) 1.00 (0.71 to 1.42)
Timing 2
CRC-specific mortality	Zell JA et al. 2009 (30) Din FV et al. 2010 (31) Coghill AE et al. 2011 (14) McCowan C et al. 2013 (34) Cardwell CR et al. 2014 (16)	0.95 (0.84 to 1.07) 0.88 (0.74 to 1.05) 0.96 (0.84 to 1.10) 0.88 (0.72 to 1.08) 0.86 (0.72 to 1.04)
All-cause mortality	Zell JA et al. 2009 (30) Din FV et al. 2010 (31) McCowan C et al. 2013 (34) Frouws MA et al. 2017 (43) Murphy C et al. 2017 (46) Rouette J et al. 2018 (53)	0.89 (0.54 to 1.45) 0.81 (0.49 to 1.33) 0.83 (0.49 to 1.43) 0.99 (0.87 to 1.13) 0.81 (0.51 to 1.28) 0.83 (0.53 to 1.31)
Timing 4
CRC-specific mortality	Chan AT et al. 2009 (29) Cardwell CR et al. 2014 (16) Bains SJ et al. 2016 (41) Hua XW et al. 2017 (17) Gray RT et al. 2018 (47) Sung JJY et al. 2019 (50)	0.75 (0.70 to 0.81) 0.76 (0.70 to 0.81) 0.72 (0.64 to 0.82) 0.76 (0.70 to 0.81) 0.75 (0.70 to 0.81) 0.77 (0.71 to 0.84)
All-cause mortality	Chan AT et al. 2009 (29) Bastiaannet E et al. 2012 (15) Walker AJ et al. 2012 (33) Bains SJ et al. 2016 (41) Hua XW et al. 2017 (17) Gray RT et al. 2018 (47) Sung JJY et al. 2019 (50)	0.81 (0.72 to 0.92) 0.82 (0.70 to 0.95) 0.82 (0.72 to 0.94) 0.82 (0.70 to 0.97) 0.82 (0.73 to 0.93) 0.82 (0.72 to 0.93) 0.87 (0.83 to 0.91)
Timing 5
CRC-specific mortality	Chan AT et al. 2009 (29) Cardwell CR et al. 2014 (16) Goh CH et al. 2014 (35) Bains SJ et al. 2016 (41) Hua XW et al. 2017 (17) Gray RT et al. 2018 (47) Sung JJY et al. 2019 (50)	0.95 (0.78 to 1.14) 0.88 (0.70 to 1.09) 0.90 (0.73 to 1.11) 0.84 (0.63 to 1.11) 0.94 (0.79 to 1.13) 0.84 (0.71 to 0.99) 0.86 (0.65 to 1.15)
All-cause mortality	Chan AT et al. 2009 (29) Bastiaannet E et al. 2012 (15) Reimers MS et al. 2012 (32) Walker AJ et al. 2012 (33) Restivo A et al. 2015 (38) Bains SJ et al. 2016 (41) Frouws MA et al. 2017 (44) Giampieri R et al. 2017 (45) Hua XW et al. 2017 (17) Gray RT et al. 2018 (47) Sung JJY et al. 2019 (50)	0.82 (0.69 to 0.96) 0.80 (0.68 to 0.96) 0.83 (0.71 to 0.97) 0.78 (0.65 to 0.93) 0.82 (0.70 to 0.95) 0.77 (0.64 to 0.92) 0.82 (0.70 to 0.97) 0.84 (0.72 to 0.98) 0.82 (0.70 to 0.97) 0.76 (0.65 to 0.88) 0.77 (0.63 to 0.95)
Timing 6
CRC-specific mortality	Chan AT et al. 2009 (29) McCowan C et al. 2013 (34) Cardwell CR et al. 2014 (16) Bains SJ et al. 2016 (41) Hamada T et al. 2017 (22) Hua XW et al. 2017 (17) Gray RT et al. 2018 (47)	0.82 (0.66 to 1.01) 0.86 (0.71 to 1.04) 0.75 (0.60 to 0.94) 0.77 (0.58 to 1.02) 0.82 (0.66 to 1.00) 0.84 (0.70 to 1.02) 0.74 (0.61 to 0.91)
All-cause mortality	Chan AT et al. 2009 (29) Walker AJ et al. 2012 (33) McCowan C et al. 2013 (34) Cardwell CR et al. 2014 (16) Reimers MS et al. 2014 (20) Bains SJ et al. 2016 (41) Hamada T et al. 2017 (22) Hua XW et al. 2017 (17) Gray RT et al. 2018 (47)	0.87 (0.77 to 0.99) 0.85 (0.74 to 0.99) 0.90 (0.80 to 1.01) 0.84 (0.73 to 0.96) 0.89 (0.79 to 1.00) 0.84 (0.72 to 0.99) 0.87 (0.77 to 0.99) 0.88 (0.77 to 1.00) 0.82 (0.74 to 0.93)

^aTiming 1 = ever-use; timing 2 = prediagnosis use; timing 4 = continued use; timing 5 = postdiagnosis use; timing 6 = aspirin use after diagnosis regardless of its usage before diagnosis. CI = confidence interval; CRC = colorectal cancer; RR = risk ratio.