Calculates the YPLL, a measure of the amount of life lost due to premature mortality.
Value
Returns a list with two components:
out: A matrix containing the number of deaths in each age group (\(d_i\)), the correspondent midpoint of age, the difference between the midpoint of age and K (\(a_i\)), and the product \(a_i d_i\).estimate: The years of potential life lost.
Details
The concept of years of potential life lost (YPLL) involves estimating the average time a person would have lived had he or she not died prematurely (Gardner and Sanborn, 1990). Denoting the number of deaths in the \(i\)-th age group by \(d_i\), the YPLL can be estimated by $$YPLL = \sum_{i=1}^{K^*} a_i d_i$$ where \(K^*\) is the number of age groups between 0 and K, \(a_i\) is the difference between K and the midpoint of age in each age group, assuming a uniform distribution of deaths in each group, and K is the standard age of death. The midpoint of an age group is estimated as (lowest age + highest age + 1)/2.
Different authors use different values for K. According to Bruce et al. (2018), historically, WHO has used life expectancy from Japan, this being the highest in the world. Other authors uses 75 years as the reference age because it approximates US life expectancy (Ma et al., 2015).
References
Bruce, N., Pope, D., Stanistreet, D. (2018). Quantitative Methods for Health Research: A Practical Interactive Guide to Epidemiology and Statistics. Second Edition. John Wiley & Sons Ltd.
Gardner, J.W., Sanborn, J.S. (1990). Years of potential life lost (YPLL) - what does it measure? Epidemiology, 1(4):322-9. doi: 10.1097/00001648-199007000-00012.
Ma, J., Ward, E.M., Siegel, R.L., Jemal, A. (2015). Temporal trends in mortality in the United States, 1969-2013. Jama, 314(16), 1731-1739. doi: 10.1001/jama.2015.12319.
Examples
# Example
d <- c(1,12,60,100,137,200,225,236,237,258,226)
ages <- seq(20,70,5)
YPLL(d,ages,75)
#> $out
#> d mid a ad
#> 20 to 24 1 22.5 52.5 52.5
#> 25 to 29 12 27.5 47.5 570.0
#> 30 to 34 60 32.5 42.5 2550.0
#> 35 to 39 100 37.5 37.5 3750.0
#> 40 to 44 137 42.5 32.5 4452.5
#> 45 to 49 200 47.5 27.5 5500.0
#> 50 to 54 225 52.5 22.5 5062.5
#> 55 to 59 236 57.5 17.5 4130.0
#> 60 to 64 237 62.5 12.5 2962.5
#> 65 to 69 258 67.5 7.5 1935.0
#> 70 to 74 226 72.5 2.5 565.0
#>
#> $estimate
#> [1] 31530
#>