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'.