How long cases take, from the counts of cases ending (and censored) in each band of time: the conditional probability of ending in each band with the censored counted as half a case at risk, the survival (the share still open at the end of each band) with Greenwood's standard error and a plain, log or log-log interval, the hazard, and the median, linear within its band.
Arguments
- breaks
The band edges, increasing (the last may be
Inf), or band labels asbandx()reads them ("0-3","Over 12"), contiguous.- events
The cases ending in each band: numbers from 0.
- cens
The cases censored in each band: one number or one per band.
- level
The level of the intervals: one number between 0 and 1.
- ci
"log-log","log"or"plain".
Value
An object of class lftab, a list: tab (lower, upper,
entering, atrisk, events, cens, q, surv, se, lo, hi,
hazard), median (Inf when survival stays above one half or
crosses it in an open band) and ci.
References
Cutler, S. J. and Ederer, F. (1958). Maximum utilization of the life table method in analyzing survival. Journal of Chronic Diseases, 8(6), 699-712. doi:10.1016/0021-9681(58)90126-7
Examples
lftab(c(0, 3, 6, 12, 24, Inf), events = c(40, 30, 20, 10, 5),
cens = c(2, 2, 3, 3, 4))
#> lftab: life table, log-log intervals, median 4.851282
#> lower upper entering atrisk events cens q surv se
#> 0 3 119 118.0 40 2 0.3389831 0.66101695 0.04357669
#> 3 6 77 76.0 30 2 0.3947368 0.40008921 0.04548923
#> 6 12 45 43.5 20 3 0.4597701 0.21614015 0.03896034
#> 12 24 22 20.5 10 3 0.4878049 0.11070593 0.03110609
#> 24 Inf 9 7.0 5 4 0.7142857 0.03163027 0.02088777
#> lo hi hazard
#> 0.568007817 0.73860814 0.13605442
#> 0.310878228 0.48760071 0.16393443
#> 0.145266720 0.29631969 0.09950249
#> 0.059213092 0.18020436 0.05376344
#> 0.006579202 0.09308838 NA