The values for the clinical probabilities were:
(1) 4 week rates of healing of ulcer with cimetidine healing dose, 80%;
(2) 4 week rate of recurrence of ulcer from state of remission, 6%;
(3) 4 week rate of recurrence of ulcer with maintenance cimetidine, 3%;
(4) Yearly rate of reinfection with H. pylori, 1%;
(5) Success of eradication at first attempt, 80%;
(6) Success of eradication after 2 attempts, 94%;
(7) Prevalence of H. pylori among dyspeptic patients under 45 years, 40%;
(8) Prevalence of peptic ulcer disease among patients positive for H. pylori, 25%;
(9) Prevalence of peptic ulcer disease among patients negative for H. pylori, 3%;
(10) Sensitivity of the serology test (for detecting H pylori), 77%;
(11) Specificity of the serology test, 89%.