Question

Discuss two ways to adjust crude death rate

Answer 1

Direct method −

1. Apply stratum-specific rates observed in the populations of interest to a reference or standard population in order to obtain the number of deaths expected in the reference population
2. Calculate an adjusted rate based on expected number of deaths in the reference population

Indirect method −

1. Apply stratum-specific reference rates to the populations of interest to obtain the number of expected deaths in each of those populations
2. Compare the observed number of deaths to the expected number of deaths for each population of interest

Adjusted Rates by the Direct Method

• Use the event rates (experience) of the population of interest to calculate the number of deaths expected in the reference population
• The adjusted rate in the population of interest is the expected number of deaths divided by the total reference population

Indirect Method of Adjustment

• Apply the experience (e.g., mortality rate) of the reference (standard) population to the population of interest (observed population) by strata (age group)
• Sum the values to obtain the expected number of deaths
• Divide the observed number of deaths by the expected number of deaths in the population of interest to get a value called SMR (Standardized Mortality Ratio)
• Multiply SMR by the crude rate (C) of the reference population to get the Indirect Adjusted Rate.