Indirect Standardisation

Indirectly standardised rates compare the actual number of events in an area (e.g. South Gloucestershire) with the expected number of events based on mortality rates of a reference population (e.g. England & Wales or European Standard Population).

This method is often used to look at differences in mortality rates, and is often referred to as the standardised mortality ratios (SMRs). The SMR is a ratio of observed to expected number of deaths. It can also be used to look at other events such as hospital activity. The observed figures comes from the local area, and the expected from applying the death rate in the reference population to the local population.
A population with an SMR under 100 has fewer deaths than expected; with over 100, more deaths than expected. 

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