RUDER—A prospective, two-year, multicenter study of risk factors for duodenal ulcer relapse during maintenance therapy with ranitidine

In a prospective study of the risk factors for duodenal ulcer relapse during maintenance (150 mg daily) ranitidine therapy, 1899 patients with chronic ulcer disease were recruited to a multicenter, German trial. Healing of all ulcers was confirmed endoscopically; endoscopy was also obligatory after one and two years or if the patients presented in the interim with symptoms of ulcer relapse. By the end of the first year, 247 patients had experienced at least one relapse and, by the end of the second year, 432 patients had relapsed at least once. The crude one- and two-year relapse rates were 13.0% (95% CI 11.5–14.5) and 22.7% (20.9–24.6%), respectively. Univariate analysis indicated that all seven prospectively defined risk factors were associated with an increased two-year relapse rate; of these, duodenal erosions distant from the healed ulcer [odds ratio (95% CI): 2.23 (1.59–3.15);P<0.0001], smoking, past or present [1.46 (1.12–1.90);P=0.0050], psychological stress [1.38 (1.09–1.74);P=0.0085], heavy physical labor [1.45 (1.06–1.98);P=0.0219], and absence of NSAID intake [1.54 (1.01–2.29);P=0.0464] were independent risk factors on stepwise logistic regression analysis, whereas persistent symptoms at healing [1.29 (1.03–1.62),P=0.0310] and frequent prior relapses [1.45 (1.01–2.04);P=0.0454] were not. Multiple relapses in 107 patients [5.63% (4.60–6.67%)] were associated with duodenal erosions, smoking, stress, and heavy physical labor. The effects of the five independent risk factors were cumulative: two-year relapse rates increased from 15.7% (95% CI 11.3–20.0%) in the presence of no or one risk factors to 40.9% (26.0–55.7%) in the presence of four or five risk factors.