268143 Effect of low dose and long term use of aspirinin primary prevention of colorectal cancer: Nationwide cohort study, Taiwan 1996-2009

Monday, October 29, 2012

Lai-Chu See , Public Health, Chang Gung University, Kweisan, Taoyuan, Taiwan
Background: High dose (300 mg+) of aspirin use daily for 5 years is effective in preventing colorectal cancer (CRC) but the effect of lower or less frequent doses of aspirin use in preventing CRC is unknown. Aims: Explore the effect of low dose (<150 mg) of aspirin on preventing CRC. Methods: Hybrid study of cohort with matched comparative group was used and was limited to adults between 18-55 years old. Two longitudinal cohorts of the Taiwan National Health Insurance Research Dataset were used. The low dose group were prescribed <150 mg aspirin daily consecutively for at least 30 days during 1998-2003 and followed until 2010. The nonuse group was matched with the user group by age, gender, three comorbidities (hypertension, DM, hyperlipidemia), index date (the user cases first prescribed aspirin). Records with CRC before aspirin being prescribed were excluded. Results: There were 24032 individuals in the nonuse group, 24032 individuals in the low dose group (3 quarters used aspirin < 3 years, 1 quarter used aspirin > 3 years). There were 149, 102, 19 CRC new cases in the nonuse group, <3 years use group, and >3 years use group, respectively, corresponding to the CRC incidence rate of 52.2, 57.4 and 31.5 per 100,000 person-year, respectively (p=0.0194). The hazard ratio of CRC for the >3 years use group was 0.64 (95% CI, 0.40 and 1.01) multivariately. Conclusions: Marginal benefit of low-dose use of aspirin for >3 years on preventing CRC was seen in Taiwan.

Learning Areas:
Biostatistics, economics
Chronic disease management and prevention
Social and behavioral sciences

Learning Objectives:
estimate the incidence rate and hazard ratio of colorectal cancer for user group (low dose and long term use of aspirin) and nonuser group.

Keywords: Cancer Prevention, Prescription Drug Use Patterns

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I designed the study, analyzed, interpreted the data, and wrote the manuscript.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.