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Writing the Abstract
Example of an Abstract Needing Improvement (Clinical Study) The following abstract could be improved: BACKGROUND: Colorectal cancer is associated with high mortality. We examined the effects of daily aspirin use on the incidence of colorectal adenomas. METHODS: Between May 15, 1993, and January 10, 2000, patients ranging in age from 30 to 80 years with a history of colorectal cancer were enrolled in the trial. We randomly assigned the 635 eligible patients to receive either aspirin at a daily dosage of 325 mg or placebo. Colonoscopy was performed at recommended intervals or as determined by each patient’s own gastroenterologist. Relative risks were adjusted for age, sex, cancer stage, the number of colonoscopic examinations, and the time to a first colonoscopy. The study was terminated early by an independent data and safety monitoring board when statistically significant results were reported during a planned interim analysis. RESULTS: A total of 517 randomized patients had at least 1 colonoscopic examination a median of 12.8 months after randomization. The mean (± standard deviation) number of adenomas was lower in the aspirin group than in the placebo group (0.30 ± 0.87 vs. 0.49 ± 0.99; P = 0.03 by the Wilcoxon test). The median size of the largest polyp was similar in the placebo group and the aspirin group (4.0 and 3.5 mm, respectively; P = 0.85 by the Wilcoxon test). The adjusted relative risk of any recurrent adenoma in the aspirin group, as compared with the placebo group, was 0.65 (95% confidence interval, 0.46–0.91). The time to the detection of a first adenoma was longer in the aspirin group than in the placebo group (hazard ratio for the detection of
a new polyp, 0.64; 95% confidence interval, 0.43–0.94; P = 0.022). CONCLUSIONS: Aspirin treatment seems to prevent colorectal cancer.
Adapted from the well-written abstract in Sandler RS et al. A randomized trial of aspirin to prevent colorectal adenomas in patients with previous colorectal cancer. N Engl J Med 348:883–890, 2003.
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