Table 3.
Univariate and multivariable hazard ratios for associations between aspirin and ibuprofen use and the risk of colorectal cancer for mismatch repair gene mutation carriers
| NSAID use | Univariate model | Multivariable model | |||||
|---|---|---|---|---|---|---|---|
| n | N | Person-years | HR (95% CI) |
P | HR* (95% CI) |
P | |
| Never user† | 622 | 1572 | 25 743 | 1 (Ref) | 1 (Ref) | ||
| Aspirin-only user | 48 | 117 | 2505 | 0.48 (0.33 to 0.71) |
<.001 | 0.43 (0.25 to 0.75) |
.003 |
| 1 month to 4.9 years | 38 | 96 | 1904 | 0.49 (0.31 to 0.76) |
.002 | 0.49 (0.27 to 0.90) |
.02 |
| ≥5 years | 10 | 21 | 601 | 0.45 (0.21 to 0.92) |
.03 | 0.25 (0.10 to 0.62) |
.003 |
| Ibuprofen-only user | 30 | 126 | 1373 | 0.33 (0.20 to 0.55) |
<.001 | 0.35 (0.19 to 0.63) |
.001 |
| 1 month to 4.9 years | 22 | 92 | 1010 | 0.36 (0.20 to 0.66) |
.001 | 0.38 (0.18 to 0.79) |
.009 |
| ≥5 years | 8 | 34 | 363 | 0.25 (0.11 to 0.58) |
.001 | 0.26 (0.10 to 0.69) |
.007 |
| Aspirin and/or ibuprofen user | 92 | 286 | 4548 | 0.40 (0.30 to 0.54) |
<.001 | 0.41 (0.28 to 0.61) |
<.001 |
| 1 month to 4.9 years | 66 | 210 | 3196 | 0.42 (0.29 to 0.59) |
<.001 | 0.44 (0.27 to 0.69) |
<.001 |
| ≥5 years | 26 | 76 | 1352 | 0.36 (0.22 to 0.57) |
<.001 | 0.34 (0.19 to 0.62) |
<.001 |
* Adjusted for year of birth (1914–43, 1944–54, 1955–65, 1966–90) and average lifetime alcohol intake (0, 1, ≥2 drinks per day) and stratified by sex, country (USA, Australia/ New Zealand, Canada), cigarette smoking status (never, former, current), regular physical activity (at least 30 minutes per week for at least three months), and multivitamin intake (<1 month, ≥1 month). All statistical tests were two-sided. CI = confidence interval; HR = hazard ratio; n = number of colorectal cancer cases; N = total number of carriers; NSAID = nonsteroidal anti-inflammatory drugs.
† Never users defined as carriers who reported not having taken either aspirin or ibuprofen or both for at least one month.