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Convert multi-year life table to single year life table

Source: R/prepare_lifetable.R
prepare_lifetable.Rd

This function determines populations and deaths by one year age groups.

Usage

prepare_lifetable(age_group, population, bhd, fraction_lived = 0.5)

Arguments

age_group

Numeric vector referring to the first years of the age groups. E.g. c(0, 20, 40, 60) means [0, 20), [20, 40), [40, 60), [60, )

population

Numeric vector referring to mid-year populations by age group.

bhd

Numeric vector referring to the baseline health data (deaths) by age group.

fraction_lived

Numeric vector Numeric vector or single numeric scalar referring to the average fraction of the age interval lived by individuals who die within that interval. Default is 0.5.

Value

This function returns a tibble containing the columns:

  • population_for_attribute (numeric) containing population values for each age

  • bhd_for_attribute (numeric) containing baseline health data values for each age

  • and more columns containing input data or results

Details

Methodology

The conversion follows the methodology of the WHO tool. See the AirQ+ manual "Health impact assessment of air pollution: AirQ+ life table manual" for guidance on how to convert larger age groups to 1 year age groups, section "Estimation of yearly values" (WHO 2020) .

fraction_lived is by default 0.5 for all age groups. However, in low-mortality settings, infant deaths are heavily concentrated in the first weeks of life. Therefore, fraction_lived can be lower e.g. 0.1 for the first age group.

When fraction_lived[1] < 0.5, the function reallocates the baseline health data (bhd) for the first age group \([0, 5)\) such that bhd[1] * (1 - fraction_lived[1]) deaths are assigned to single-year age 0, and the remaining deaths are split equally across single-year ages 1–4.

Detailed information about the methodology (including equations) is available in the package vignette. More specifically, see chapters:

References

WHO (2020). “Health impact assessment of air pollution: AirQ+ life table manual.” World Health Organization - Regional Office for Europe. https://www.who.int/europe/publications/i/item/WHO-EURO-2020-1559-41310-56212.

See also

Author

Alberto Castro & Axel Luyten

Examples

# Goal: Convert 5-year population and death data into single year life table
results <- prepare_lifetable(
  age_group = c(0, 5, 10, 15),
  population = c(3387900, 3401300, 3212300, 3026100),
  bhd = c(4727, 472, 557, 1323)
)