Direct standardization is used to compare the mortality rates between two countries. This is done because of the difference in:
Ans. c. Age distributions (Ref: Park 23/e p58, 10/e p54)Direct standardization is used to compare the mortality rates between two countries. This is done because of the difference in age distributions."Because of the differences in age distribution of two populations, their mortality experience could not he compared by sued 'crude death rate' as it leads to wrong impression. A population (say population A) with more young people would have low crude death rate than a population (population B) with more old people, thus giving an impression that population A is healthier than B. which may not be so. This confounding effect of age is removed by means of 'standardization'."Standardization of Death RatesAdjusted or standardized rates:While comparison of death rates of two populations, 'crude death rate is not the right yardstick', as age- compositions are differentAge-adjustment or age-standardization removes confounding effect of different age structuresStandardization may be direct or indirectTypes of Standardized Death RatesDirect standardizationIndirect standardizationMethod:* Age-specific rates of the population (whose crude death rate is to be standardized) is applied on a standard population* Total expected deaths calculated* Total expected deaths divided by total standard population to yield standardized death rateFeasibility:* Availability of age-specific death rates (ASDRQ)* Availability of population in each age group* Standardized mortality ratio (SMR) (Ref: Is simplest and most useful form)* Method: Calculate expected deaths, assuming that study group experiences the death rates of a standard population* Feasibility: Permits adjustment where age-specific rates are not available or are unstable because of small numbers* Examples of indirect StandardizationQ:- Standardized mortality ratio (SMR = Observed deaths/ Expected deaths x 100)- Life Table Analysis- Survival Analysis- Regression Analysis- Multivariate Analysis
Causes of death
Denominators
Age distributions
Numerators
Epidemiology