Table 1

Four strata for disproportionate stratification based on cause of death*

Stratum 0
Cause of death implies that an ELD is certain
Included causes of death: euthanasia**.
Every death in this stratum is selected for the survey.

Stratum 1
Cause of death implies that an ELD is probable
Included causes of death: neoplasms (ICD-10 codes: C, D00–D48).
One out of every two deaths in this stratum is selected for the survey.

Stratum 2
Cause of death implies that an ELD is possible
Included causes of death: endocrine, nutritional and metabolic diseases; mental and behavioural disorders; diseases of the nervous system; diseases of the respiratory system; diseases of the digestive system; diseases of the genitourinary system (ICD-10 codes: E, F, G, J, K, N).
One out of every four deaths in this stratum is selected for the survey.

Stratum 3
Cause of death implies that an ELD is improbable
All remaining causes of death are included in this stratum (ICD-10 codes: A, D50–D99, H, I, L, M, Q, R, S, T, U, V, Y).
One out of every eight deaths in this stratum is selected for the survey.

* Causes of death were grouped into strata based on the probability of an ELD as observed in the Flemish part of the EURELD six nations study (2001) [14].

** Although there is no box to specify euthanasia in the death certificate, it is occasionally written down by the certifying physician in the section 'immediate cause of death'.

Chambaere et al. BMC Public Health 2008 8:299   doi:10.1186/1471-2458-8-299