Regarding standardization, all of the following statements are true, EXCEPT:
A 'Standard population' is defined as a population in which the numbers of people present in each age group and sex group are known. The choice of deciding on standard population is arbitrary. National population can be used as the standard population, but definitely cannot be taken as a standard population always. Moality rates between two countries are not comparable because these populations have different Age compositions. The difference in age between two sets of population (two countries) does not allow the moality rates of the two populations to be compared. Direct standardization is used to remove the difference in age distribution thus allowing the comparison of moality rates. Ref: Park's Textbook of Preventive and Social Medicine, 19th Edition, Pages 54 - 55.
Standardisation allows comparison to be made between two different two different populations
For direct standardization, age specific rates of the study population are applied to that of the standard population
For indirect standardization, age specific rates of the study population are applied to that of the study population
National population is always taken as the standard population is always taken as the standard population