This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
All are true of standardized mortality ratio except - 
Select and explain. 
A. Expressed as rate per year, B. Can be adjusted for age, C. Can be used for events other than death, D. Ratio of observed deaths to expected deaths
A: Expressed as rate per year
Answer: A: Expressed as rate per year 
Explanation: Standardization is most commonly used for age.
Standardization can be used not only for age, but also sex, race, parity, etc.
SMR is the ratio of observed death to expected death and it is usually expressed as a percentage.
SMR is commonly used in occupational studies for comparison of morality in an industry and general population.
SMR can be used for occurrence of disease (rather than death).