LifeTable function

Compute Life Tables from Mortality Data

Construct either a full or abridged life table with various input choices like: death counts and mid-interval population estimates (Dx, Ex) or age-specific death rates (mx) or death probabilities (qx)

or survivorship curve (lx) or a distribution of deaths (dx). If one of these options is specified, the other can be ignored. The input data can be an object of class: numerical vector, matrix or data.frame.

LifeTable(x, Dx = NULL, Ex = NULL,
             mx = NULL,
             qx = NULL,
             lx = NULL,
             dx = NULL,
             sex = NULL,
             lx0 = 1e5,
             ax  = NULL)

Arguments

• x: Vector of ages at the beginning of the age interval.
• Dx: Object containing death counts. An element of the Dx object represents the number of deaths during the year to persons aged x to x+n.
• Ex: Exposure in the period. Ex can be approximated by the mid-year population aged x to x+n.
• mx: Life table death rate in age interval [x, x+n).
• qx: Probability of dying in age interval [x, x+n).
• lx: Probability of survival up until exact age x (if l(0) = 1), or the number of survivors at exact age x, assuming l(0) > 1.
• dx: Deaths by life-table population in the age interval [x, x+n).
• sex: Sex of the population considered here. Default: NULL. This argument affects the first two values in the life table ax column. If sex is specified the values are computed based on the Coale-Demeny method and are slightly different for males than for females. Options: NULL, male, female, total.
• lx0: Radix. Default: 100 000.
• ax: Numeric scalar. Subject-time alive in age-interval for those who die in the same interval. If NULL this will be estimated. A common assumption is ax = 0.5, i.e. the deaths occur in the middle of the interval. Default: NULL.

Returns

The output is of the "LifeTable" class with the components: - lt: Computed life table;

• call: Call in which all of the specified arguments are specified by their full names;

• process_date: Time stamp.

Details

The "life table" is also called "mortality table" or "actuarial table". This shows, for each age, what the probability is that a person of that age will die before his or her next birthday, the expectation of life across different age ranges or the survivorship of people from a certain population.

Examples

# Example 1 --- Full life tables with different inputs ---

y  <- 1900
x  <- as.numeric(rownames(ahmd$mx))
Dx <- ahmd$Dx[, paste(y)]
Ex <- ahmd$Ex[, paste(y)]

LT1 <- LifeTable(x, Dx = Dx, Ex = Ex)
LT2 <- LifeTable(x, mx = LT1$lt$mx)
LT3 <- LifeTable(x, qx = LT1$lt$qx)
LT4 <- LifeTable(x, lx = LT1$lt$lx)
LT5 <- LifeTable(x, dx = LT1$lt$dx)

LT1
LT5
ls(LT5)

# Example 2 --- Compute multiple life tables at once ---

LTs = LifeTable(x, mx = ahmd$mx)
LTs
# A warning is printed if the input contains missing values.
# Some of the missing values can be handled by the function.

# Example 3 --- Abridged life table ------------

x  <- c(0, 1, seq(5, 110, by = 5))
mx <- c(.053, .005, .001, .0012, .0018, .002, .003, .004,
        .004, .005, .006, .0093, .0129, .019, .031, .049,
        .084, .129, .180, .2354, .3085, .390, .478, .551)
LT6 <- LifeTable(x, mx = mx, sex = "female")
LT6

# Example 4 --- Abridged life table w using my own 'ax' ------------
# In this examples we are using the ages (x) and death rates (mx) from
# example 3. Note that 'ax' must have the same length as the 'x' vector
# otherwise an error message will be returned.

my_ax <- c(0.1, 1.5, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
           2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1)

LT7 <- LifeTable(x = x, mx = mx, ax = my_ax)

See Also

LawTable

convertFx

Author(s)

Marius D. Pascariu