Life tables Flashcards
Age interval, x to x+n
Age interval between exact ages for each row of life table
Death rate in the cohort between ages x and x+n (ASDR)
Proportion of population in each age interval that are alive at beinning of interval and dead before reaching end of interval.
Computed from observed mortality rates of an actual population and is used to derive remaining columns of life table.
(n*Mx) / (1+(.5*n*Mx), where:
n = length of age interval
Mx = age-specific death rate
Probability of surviving from age x to age x+n.
1-qx
The number of persons alive at the age interval.
lx(0) = 100,000
lx(1) = lx(0)-dx(0)
OR
lx(1) = lx(0) * px(0)
The number of persons who die within the indicated age interval (x to x+n).
dx = lx * qx
(open-ended interval: all died)
The number of person-years lived within the indicated age interval (x to x+n) by all persons from age x to x+n.
Lx = 0.5(lx + lx+1)
example: L20 = 0.5(L20 + L21)
(different for age 0 and age 1)
L0 = 0.3*l0 + 0.7*l1
L1 = 0.4*l1 + 0.6*l2
(not terminal)
Llast = L85 = lx / mx = l85 / m85
Total number of person-years lived after the beginning of the indicated age interval. Cumulative from bottom-up.
Tlast = Llast; (Example: T85 = L85)
Tlast-1 = Llast + Llast-1; (Example: T84 = T85 + L84; T83 = T84 + L83)
Expectation of life at age x; life expectancy.
ex = Tx / lx
Calculation of survival rates from life table.
Survival rate calculation (example)
Proportion of population age 45-49 that will survive 5 years.
Survival rate calculation for age 0-4
5 is the age interval.
Survival rate calculation for age 5-9
Survival rate calculation for 85+
Age-specific death rate
Crude Birth Rate (CBR)
