# Cumulative Expected Method

#### Hakulienen Exact and Hakulinen Simplified

The exact and simplified adjustment in the calculation of expected survival is described in detail in:

Hakulinen T, Abeywickrama KH. A computer program package for relative survival analysis. *Computer Programs in Biomedicine* 1985;19:197-207.

The simplified method approximates the exact calculation. Both options are included in the program to allow for comparisons with existing software that use one of the options when calculating expected survival.

#### Ederer I and Ederer II

Ederer I method calculates the expected survival rates assuming each patient would be a member of the general population from diagnosis to entire follow-up so the matched individuals are considered to be at risk indefinitely.

Ederer II method calculates the expected survival rates for patients under observation at each point of follow-up so the matched individuals are considered to be at risk until the corresponding cancer patient dies or is censored.

For more information on the Ederer methods, see http://surveillance.cancer.gov/reports/tech2011.01.pdf.