Table 2.
Distribution by age for each risk group (Unit %)
| Risk categorya | Distribution by ageb | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| 0–9 | 10–19 | 20–29 | 30–39 | 40–49 | 50–59 | 60–69 | 70–74 | 75+ | |
| A | 99 | 95 | 89.5 | 85.5 | 80 | 65 | 55 | 50 | 50 |
| B | 1 | 4 | 8 | 11 | 15 | 20 | 20 | 15 | 15 |
| C | 0 | 1 | 2 | 3 | 4 | 13 | 20 | 25 | 25 |
| D | 0 | 0 | 0.5 | 0.5 | 1 | 2 | 5 | 10 | 10 |
aGroup A: H. pylori (HP) negative [−]/atrophic gastritis (AG) negative [−], Group B: HP positive [+]/AG [−], Group C: HP [+]/AG [+], Group D: HP [−]/AG [+].
bThe prevalence of individuals aged 0–9 years was defined as 99% for Group A, and the prevalence of age groups from 10 to 39 years old was interpolated by applying a linear regression model to the prevalence of age groups of 0–9 and 40–49 years old.
The prevalence of individuals aged 40–74 years was obtained from the Japan Public Health Center-based Prospective Study for the Next Generation data.
The prevalence of individuals aged 75 years or older was assumed to be the same as that of individuals aged 70–74 years.