Age standardized rates are calculated for population to overcome the differences in age compositions. I do not see any sense in calculating age standardized rate for each age group

I do agree with Dr Habib. Basic intention of age standardization is to overcome the differences of age composition between the two population group. So in direct standardization it will be always overall standardized rate of two population groups. For each group it may be possible to calculate the national figure i.e. age specif mortality rate of age group 15 - 20 years etc. But this is not standardized rate.

Dear Omran, Dear Indranil

You can see Table 1 in the following article that shows age-standardized death rate for each age group.

https://www.thelancet.com/journals/langlo/article/PIIS2214-109X%2815%2900091-1/fulltext

Age standardization is done because of differences of mortality in different age groups. What they have done is absolutely correct. Since they have assumed that "This calculation assumed constant mortality within each of the 11 5-year age intervals from ages 15 to 69 years, or within the relevant intervals in each of the smaller age groupings (15–29 years, 30–69 years, etc)" - written in methodology. Thus it was assumed that in 0 -14 years of age group: in 0 - 4, 5 - 9, and 10 - 14 years mortality rate is constant i.e. no variation. Here they have taken world population as standard population. They have calculated age specific mortality rate of different region of this specified age group. Then this rate was applied to standard world population to find out the expected number of deaths / 1000. This rate was presented as age-standardised mortality rate in this article.

Dear Indranil,

Thanks for your answer. What is your opinion about the following article (Tables 1& 2)?

http://www.aimjournal.ir/Abstract/aim-2006

Although late answer. I totally agree with Indranil Saha, Age standardised rates are used to overcome variation in mortality in different population associated with non-identical age distribution.