Session 2 Standardisation

• A set of techniques used to remove as much as possible the effects of differences in age or other confounding variables when comparing two or more populations. - standardisation
• Indirect comparison: When a target population is compared to a standard population
• Direct comparison: When a number of populations are compared to a standard population as template.
• Standardized mortality ratio = Observed deaths/expected deaths
• SMR values <1 indicate lower than expected mortality in the target population compared with the standard population.
• SMR values >1 indicate higher than the age specific death rate per thousand population expected mortality.
• Prevalence = No. of cases at a given time/ Population at a given time.
• Incidence = no. of new cases at a given time/ 'at risk' population