ABSTRACT
This Chapter is about the measurement of disease frequency and discusses a range of methods.
Measures covered include disease frequency, incidence and prevalence, crude rates plus specific and age-specific rates. The strengths and weaknesses of each method are explained, along with examples of their calculation and use in practice.
Other terms discussed are morbidity, mortality and person years at risk.
Direct and indirect standardisation are then introduced and separately discussed, and guidance is provided on situations when each approach should be used. Fully worked step-by-step instructions are provided for the calculation of age standardised death rates and standardised mortality ratios (SMR) along with their interpretation.
