Hp-normogram (normo-graham) for Assessing the Outcome of H-pylori Therapy: Effect of Resistance, Duration, and CYP2C19 Genotype

There have been hundreds of H. pylori eradication trials and yet doubt remains regarding the best regimen for any situation. With most regimens, treatment failure is the result of resistance to one component (e.g., clarithromycin). Thus, if one knows the treatment success with two groups (all with susceptible and with all with resistant infections), one can construct a normogram that provides a reliable estimate of the outcome at any prevalence of resistance. The same data can be used to estimate the prevalence of resistance in any clinical trial, the effects duration of therapy, and effects of any procedures to improve outcome (e.g., increasing the proton-pump inhibitor dose, the duration of therapy, etc.). Because the Hp-normo-graham can reliably predict the outcome of clinical trials, it can also obviate the need for many clinical trials in populations where resistance is common. Here, we illustrate the construction of Hp-normo-graham and its use to describe the effects of resistance, duration of therapy, attempts to improve results, and the prevalence of resistance and to obviate the need for many clinical trials.