Clinical and economic effects of population-based Helicobacter pylori screening to prevent gastric cancer.

BACKGROUND Helicobacter pylori infection has been identified as a risk factor for certain types of gastric cancer. However, the extent to which H. pylori eradication decreases the risk of gastric cancer is unknown, raising the question of whether population-based H. pylori screening should be undertaken. OBJECTIVE To compare clinical and economic effects of H. pylori screening, with and without confirmatory testing, with no screening to prevent gastric cancer. DESIGN Decision analysis incorporating a Markov simulation. PATIENTS Simulated cohorts of men and women with varying risk of gastric cancer. INTERVENTION Three strategies were evaluated: (1) no screening; (2) H. pylori serologic testing, treat those positive for H. pylori, no follow-up testing; and (3) H. pylori serologic testing, treat those positive for H. pylori, followed by a test to confirm H. pylori eradication, retreat those who test positive. In the principal analysis, the risk of gastric cancer after H. pylori eradication was assumed to be similar to that for those without H. pylori infection. Scenarios with less optimistic assumptions regarding risk reduction of cancer were evaluated. MAIN OUTCOME MEASURES Gastric cancer rates, discounted cost per life-year saved. RESULTS If H. pylori eradication reduced the risk of cancer to that of people never infected, both H. pylori intervention strategies reduced gastric cancer rates so that each yielded at least 12 additional life-years per 1000 40-year-old white men screened when compared with no screening. Helicobacter pylori serologic testing without posttreatment confirmatory testing resulted in the lowest cost per additional life-year saved (S6264). The cost-effectiveness of the H. pylori screening strategies varied substantially as the level of risk reduction of cancer was varied, but remained cost-effective even at moderate rates (<30%) of excess risk reduction of cancer in all cohorts evaluated. CONCLUSIONS Population-based H. pylori screening has the potential to produce important health benefits at a reasonable cost at moderate rates of excess risk reduction of cancer. Controlled studies are necessary to confirm and quantify the impact of H. pylori eradication on the risk of gastric cancer.