Table 3. Cumulative Tablet-Days of Analgesic Use and Risk of Epithelial Ovarian Cancer in the NHS and NHSII During Follow-up From 2000 to 2015.
| Tablet-Days | Low-Dose Aspirin | Standard-Dose Aspirin | NSAIDs | Acetaminophen | ||||
|---|---|---|---|---|---|---|---|---|
| No. of Cases | Multivariable-Adjusted HR (95% CI)a | No. of Cases | Multivariable-Adjusted HR (95% CI)a | No. of Cases | Multivariable-Adjusted HR (95% CI)a | No. of Cases | Multivariable-Adjusted HR (95% CI)a | |
| None | 287 | 1 [Reference] | 276 | 1 [Reference] | 199 | 1 [Reference] | 293 | 1 [Reference] |
| 1-499 | 21 | 1.03 (0.66-1.61) | 33 | 1.11 (0.77-1.60) | 59 | 1.22 (0.90-1.64) | 86 | 1.24 (0.97-1.59) |
| 500-999 | 6 | 1.16 (0.51-2.63) | 6 | 0.97 (0.43-2.19) | 18 | 1.06 (0.65-1.74) | 23 | 1.34 (0.87-2.07) |
| 1000-2499 | 61 | 0.75 (0.57-1.00) | 53 | 1.26 (0.93-1.70) | 65 | 1.15 (0.86-1.53) | 55 | 1.09 (0.81-1.46) |
| ≥2500 | 27 | 0.77 (0.50-1.19) | 21 | 1.58 (1.00-2.48) | 58 | 1.65 (1.19-2.28) | 39 | 1.41 (0.99-2.00) |
| P value for trend | .05 | .02 | .006 | .10 | ||||
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); HR, hazard ratio; NHS, Nurses’ Health Study; NHSII, Nurses’ Health Study II; NSAIDs, nonsteroidal anti-inflammatory drugs.
Hazard ratios and 95% CIs for each drug type (ie, low-dose aspirin, standard-dose aspirin, nonaspirin NSAIDs, and acetaminophen) were estimated using separate Cox proportional hazards regression models. Models allowed for variation in baseline hazards by cohort, age in months (continuous), and calendar years (continuous) and were adjusted for menopausal status, parity (ever vs never and number of children), duration of oral contraceptive use (never, <1, 1 to 5, or >5) in years, duration of postmenopausal hormone use by type, history of tubal ligation (yes vs no), history of hysterectomy (yes vs no), family history of breast cancer or ovarian cancer (yes vs no), and BMI (<20, 20 to <25, 25 to <30, or ≥30).