Get population attributable fraction

This function calculates the population attributable fraction (PAF) of a health outcome due to exposure to an environmental stressor

Usage

get_paf(rr_at_exp, prop_pop_exp)

Arguments

rr_at_exp: Numerical value Risk estimate of the concentration response function for a specific concentration. The population attributable fraction is normally calculated using the risk estimate that refers to the concentration that reflects the population exposure and the cut-off. This risk estimate is obtained after re-scaling from the epidemiological study with a particular increment (e.g. for PM2.5 10 or 5 ug/m3) to the aimed concentration.
prop_pop_exp: Numeric value or numeric vector specifying the population fraction(s) exposed for each exposure (category). Default: 1. See Details for more info. Only applicable in RR pathways.

Value

This function returns the population attributable fraction as a numeric value.

Details

Methodology

This function is called internally inside other healthiar functions, e.g. attribute_health(). The function calculates the population attributable fraction (i.e. the percent of health cases that are attributable to the exposure) based on the relative risk as described in the extensive existing literature (WHO 2003; Steenland and Armstrong 2006; Lehtomäki et al. 2025) .

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

relative risk

References

Lehtomäki H, Aasvang GM, Sulo G, Denby BR, Hänninen OO, Brauer M, Pereira G, Dadras O, Bølling AK (2025). “Burden of disease attributable to PM2.5 at low exposure levels: impact of methodological choices.” Environmental Health, 25(1), 4. ISSN 1476-069X, doi:10.1186/s12940-025-01250-y .

Steenland K, Armstrong B (2006). “An overview of methods for calculating the burden of disease due to specific risk factors.” Epidemiology, 17(5), 512–519. doi:10.1097/01.ede.0000229155.05644.43 .

WHO (2003). “Introduction and methods: Assessing the environmental burden of disease at national and local levels.” World Health Organization. https://www.who.int/publications/i/item/9241546204.

Author

Alberto Castro & Axel Luyten

Examples


# Goal: calculate PAF based on RR and the proportion of population exposed
get_paf(rr = 1.062, prop_pop_exp = 1)
#> [1] 0.05838041