Rates commonly used in epidemiology
See also standardisation (mortality).
| Rate (per annum) | Numerator | Denominator | Notes |
|---|---|---|---|
| General fertility rate | No of births | Women age 15-44 (1000s) | 64.3 per thousand in UK in 1990 |
| Crude birth rate | No of births | Total population includes men women and children (1000s) | 13.9 per thousand in UK in 1990 |
| Age-specific fertility rates | No of births per women of specific age range | No of women in that age range (1000s) | - |
| Total period fertility rate | Summarises age-specific rates: live births per woman if all women experienced the average number of births for each age range, throughout her reproductive life. | Per woman. |
1.84 in UK in 1990.
2.1 is replacement figure in UK (>2 due to deaths before reaching child-bearing age). |
| Stillbirth rate | No of stillbirths (>24/40 since 1992, >27/40 previously) | Total births (1000s) | 4.6 per thousand in UK in 1990 |
| Perinatal mortality rate (PNMR) | Stillbirths + deaths in early neonatal period (within first week of life) | Total births (1000s) | - |
| Early neonatal mortality rate | Deaths in early neonatal period (within first week of life) | Live births (1000s) | - |
| Late neonatal mortality rate | Deaths in late neonatal period (between 7th and 28th day of life) | Live births (1000s) | (150 per thousand at end of last century; 58.7 in 1936; ~8 in 1990 (UK) |
| Neonatal mortality rate | Deaths in first 28 days of life | Live births (1000s) | 4.5 per thousand in UK in 1990 |
| Post neonatal mortality rate | Deaths after 28 days but within the first year of life | Live births (1000s) | 3.2 per thousand in UK in 1990. Strongly associated with social class etc. |
| Infant mortality rate | Deaths within the first year of life | Live births (1000s) | 7.7 per thousand in UK in 1990. |
| Maternal mortality rate | Deaths occurring "while pregnant or within 42 days (6/52) of termination of pregnancy from any cause related to or aggravated by pregnancy or its management, but not from accidental or incidental causes". See also Maternal deaths. | Total births (100 000s) | 1/200 a turn of century; one in 13 000 in 1990. |
| Crude death rate | No of deaths | Total population (1000s or 10,000s) | Expresses mortality as a single figure, but varies with demography. Rate >1/10k is an emergency |
| Case fatality rate | No of deaths from a specific disease | No of cases with the same disease (1000s) | - |
| Incidence rate | Number of new cases over a defined period | Population at risk | - |
| Prevalence | Total number of cases at a point in time, or during a period of time (point or period prevalence) | Population at risk | - |