This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'Which of the following is best to compare the vital statistics of countries? \nSelect and explain. \nA. Crude death and birth rates, B. Age standardized death rate, C. Proportional mortality rate, D. Age specific death rate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. b (Age standardized death rate) (Ref. Park PSM 22nd/, p 54)Age standardized death rate or age adjustment which removes the confounding effect of different age structures and yields a single standardized or adjusted rate by which the mortality experience can be compared directly.Crude Death RateCause-specific Crude Death RateAge-standardized Death RateAge-specific Death Rate: Total number of deaths divided by estimated mid-year population per 1,000.: Number of cause-specific deaths divided by estimated mid-year population per 1,000.: Death rate estimated after age-standardization has been performed.: Total number of deaths divided by mid-year population per 1,000 for specific age', 'role': 'assistant'}]