In this survey, the method of indirect standardisation is employed. The actual number of deaths in the index population (in this case a particular ethnic group) is compared to the anticipated number of deaths on the basis of age-specific mortality rates in the standard population (native Dutch in the period 2003-2005). The quotient of these two, the Standardised Mortality Ratio (SMR) thus indicates how many more or fewer suicides there are in relative terms in the index population than in the standard population, if the age distribution in the standard population would have been the same as in the index population. A reliability interval is used to determine whether the SMR of the index population deviates significantly from the standard population. In the second graph, the SMRs of the ethnic background groups have been multiplied by 100 and in the first graph by the mortality rate for native Dutch. These multiplications do not affect the relations in the graph, but only change the vertical scale.
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