CDM Table name: DEATH (Tentative name: Death_ONS in database)
Reading from ONS.Death
Linkage between ONS Mortality data and CPRD primary care data uses an eight-step deterministic linkage algorithm based on four identifiers, shown in Table 1 below. Postcode in the ONS data is based on the usual residence of the deceased as recorded in the death registration data. The linkage is undertaken by NHS Digital, acting as a trusted-third party, on behalf of CPRD. No personal identifiers are held by CPRD, or included in the CPRD GOLD, CPRD Aurum, or linked death registration data.
| Step | Match |
|---|---|
| 1 | Exact NHS number, sex, date of birth (DOB), postcode |
| 2 | Exact NHS number, sex, DOB |
| 3 | Exact NHS number, sex, postcode, partial DOB |
| 4 | Exact NHS number, sex, partial DOB |
| 5 | Exact NHS number, postcode |
| 6 | Exact sex, DOB and postcode(where the NHS number does not contradict the match, the DOB is not 1st of January and the postcode is not on the communal establishment list) |
| 7 | Exact sex, DOB and postcode(where the NHS number does not contradict the match and the DOB is not 1st of January) |
| 8 | Exact NHS number |
The matching steps are applied sequentially. If a CPRD GOLD or CPRD Aurum patient record is matched in one step, it is no longer available for matching in subsequent steps.
CPRD provides users with a match_rank variable which corresponds to the step at which the match was established. In general, a lower value for the match_rank is considered stronger evidence for a positive match.
ONLY ONS death data with match_rank =1 or 2, within the linkage_coverage period and valid in the database linked (i.e. patients do not exists in the source_nok) to are used in our mapping. For Details, please refer to the paper.
| Destination Field | Source field | Logic | Comment field |
|---|---|---|---|
| person_id | patid | ||
| death_date | dod | ||
| death_datetime | dod | ||
| death_type_concept_id | 32815 - Death Certificate | ||
| cause_concept_id | cause | cause_source_value will be mapped to SNOMED Concept_id by using ONS_DEATH_CAUSE_STCM, ICD10 and ICD9CM | Map cause_source_value by using ONS_DEATH_CAUSE_STCM, ICD10 and ICD9CM in follwoing sequence and conditions. 1. map the cause_source_value by ONS_DEATH_CAUSE_STCM. 2. If it does not match, map by ICD10 and ICD9CM. 3. If it does not match, map SUBSTRING(cause_source_value from 0 for 4) by ICD10. It does not allow multiple death records for a single person in CDM Death. However, some ICD10 and ICD9CM codes map to multiple standard concepts in Athena. ONS_DEATH_CAUSE_STCM, an STCM-tailored vocabulary, contains the mapping information between these codes and standard concepts. ICD10 and ICD9CM codes with multiple ‘Maps to’ associations (i.e., maps to multiple standard concepts), ICD10 codes co-exist in ONS_DEATH_CAUSE_STCM, and ICD9CM codes co-exist in ICD10 or/and ONS_DEATH_CAUSE_STCM are disregarded in the mapping. |
| cause_source_value | cause | ||
| cause_source_concept_id | cause |