Indirect adjustment is characterized by which statement?

• A. It applies observed standard rates to the study population to compute expected deaths.
• B. It compares the study population's rates to a standard population and uses the study group's base population.
• C. It uses a completely outside standard population to compute adjusted rates.
• D. It requires detailed age-specific rates for all age groups.

Answer: (B)

Indirect adjustment centers on using rates from a standard population and applying them to the study population’s own age distribution to estimate what would be expected. This means you compare the observed outcomes in the study group to the numbers you’d expect if the study group had the standard rates, weighting by the study group’s population structure. The key point is that you don’t need the study population’s own detailed age-specific rates; you rely on the standard rates and the study population’s base distribution to compute expected counts and then compare observed to expected (often via the SMR). That aligns with the idea of applying external rates to the study group’s age distribution, which is captured by the statement.