Use this mortality or life-table method when age intervals, deaths, exposures, survivorship, and open-ended interval assumptions refer to the same population and period.

Age

Starting age x of the summation; used for labeling only.

Person-years L

Person-years lived Lx for each successive interval beginning at age x.

Tx

Total person-years lived Tx above the starting age.

Life-table results depend on age grouping, exposure quality, the treatment of the first and terminal intervals, and assumptions about deaths within each interval. Sparse deaths can make rates unstable.

Complement a summary mortality result with age-specific death rates, survivorship, and exposure counts. A complete life table is preferable when the question involves several ages or remaining life expectancy.

• NLX Person Years Lived Calculator

  Compute the life-table person-years lived Lx as n times the average of lx and lx-next for an ordinary abridged interval, or as lx divided by nmx when the open terminal interval death rate is supplied.

• AX Average Years Dying Rule Calculator

  Compute the average person-years lived by those dying in an interval under the midpoint rule (a = n/2) or the Coale-Demeny infant rule (a0 = 0.07 + 1.7 m0), then convert the death rate to the life-table probability of dying q = n m / (1 + (n - a) m).

• Person Years Exposed Risk Computation

  Sum exact exposure spells into total person-years lived at risk and convert an event count into the mean exposure per person and the incidence rate per thousand person-years.