slightly significantP = 0.045
The population study in Ho Chi Minh showed slightly significant lower age than that in Hanoi (mean age, 61.3 vs 64.5 years old, P = 0.045, respectively); however, among the diffuse type groups, there was no statistically different age distribution between Hanoi and Ho Chi Minh (mean age, 59.7 vs 63.2 years old, P = 0.13, respectively).