Proximal disease (530/109) | Distal/rectal disease (833/148) | |||||
Total/events | HR | 95% CI | Total/events | HR | 95% CI | |
NSAID use | ||||||
Never | 242/64 | 1.00 | Referent | 402/73 | 1.00 | Referent |
Ever | 282/43 | 0.55 | 0.37 to 0.82 | 424/74 | 1.00 | 0.72 to 1.41 |
Current | 179/29 | 0.57 | 0.36 to 0.89 | 241/40 | 0.98 | 0.66 to 1.47 |
Former | 100/12 | 0.46 | 0.25 to 0.86 | 180/34 | 1.08 | 0.71 to 1.65 |
Aspirin use | ||||||
Never | 293/72 | 1.00 | Referent | 487/88 | 1.00 | Referent |
Ever | 234/36 | 0.62 | 0.40 to 0.94 | 342/59 | 1.03 | 0.72 to 1.47 |
Current | 145/23 | 0.58 | 0.38 to 0.96 | 201/33 | 0.97 | 0.63 to 1.50 |
Former | 89/13 | 0.46 | 0.25 to 0.86 | 141/26 | 1.11 | 0.70 to 1.75 |
Ibuprofen use | ||||||
Never | 425/93 | 1.00 | Referent | 671/116 | 1.00 | Referent |
Ever | 103/15 | 0.55 | 0.31 to 0.99 | 159/32 | 1.16 | 0.77 to 1.74 |
Current | 47/7 | 0.56 | 0.24 to 1.31 | 56/12 | 1.23 | 0.66 to 2.32 |
Former | 56/8 | 0.54 | 0.26 to 1.14 | 103/20 | 1.18 | 0.69 to 1.82 |
The p value calculated from a full model using an interaction term between tumour site (proximal vs distal/rectal) and NSAID use (ever vs never) was 0.08.
All models in the table are adjusted for age (continuous), sex, body mass index (continuous), smoking, screening, diabetes, prior inflammatory conditions, first-course treatment and stage of disease at diagnosis.
All definitions for NSAID use patterns are the same as outlined for table 2. As reported in table 2, not every case who responded to the ‘ever vs never’ NSAID question responded to the question asking whether the case was using at the point in time 2 years prior to diagnosis, such that the current and former users to not exactly total to the ever users, with three cases missing.