What is the direct method used for adjusting rates?

• A. Direct method
• B. Indirect method
• C. Crude method
• D. Proportional method

Answer: (A)

Direct adjustment removes the influence of a population’s age structure by using the study population’s own age-specific rates and applying them to a standard population. This yields an age-adjusted rate that answer: what would the overall rate be if the population had the same age distribution as the standard? You compute it by taking each age-specific rate, multiplying it by the number of people in the corresponding age group of the standard population, summing those products, and dividing by the total size of the standard population. This gives a rate that can be compared across populations with different age structures, assuming the age-specific rates are stable enough to estimate. When counts in some age groups are too small, the indirect method is used instead, because it relies on external age-specific rates. The crude rate is simply the overall rate without any adjustment for age, and the proportional method is not a standard approach for rate adjustment.