This ID is unique to each individual. It has been assigned sequentially and bears no resemblence to any real personal identifier.
These data are based on real data from a national cancer registry, but  the original data have been permuted so that the day and month of exit for individuals who die have been permuted.
These data are based on real data from a national cancer registry, but the original data have been permuted so that the day and month of diagnosis are  random but the survival time is close to the actual survival time.
Contains survival time in completed years plus one half. This prevents Stata from excluding observations with zero survival time and also gives a good representation of the average person-time at risk.
Contains survival time in completed months plus one half. This prevents Stata from excluding observations with zero survival time and also gives a good representation of the average person-time at risk.