Table name: drug_exposure
Reading from gp_prescriptions
Drug code either in read_2, bnf_code or dmd_code. Mutually exclusive.
If date is emtpy or in 2037, skip the record.
| Destination Field | Source field | Logic | Comment field |
|---|---|---|---|
| drug_exposure_id | |||
| person_id | eid | ||
| drug_concept_id | dmd_code read_2 drug_name | Coding priority: use dm+d, then read, then drug name. Skip record if only BNF code available (not complete and not specific enough). | Some codes in dmd_codes are not dm+d codes, but unknown codes. These codes don’t have a mapping. |
| drug_exposure_start_date | issue_date | If 1902-02-02 or 1903-03-3, set date to yob-07-01 (field 34 in baseline) | |
| drug_exposure_start_datetime | |||
| drug_exposure_end_date | issue_date quantity | No drug end date available, estimate using Themis convention: either same as start date (if no valid quantity available), or 1 day x quantity (valid if expressed as: tablets, capsules, doses, strips, sachets, units, or a whole number without unit; other units such as volume will be ignored). | Date estimate from quantity available for > 68% of unique values in scan report. |
| drug_exposure_end_datetime | |||
| verbatim_end_date | |||
| drug_type_concept_id | 32838 - ‘EHR prescription’ | ||
| stop_reason | |||
| refills | |||
| quantity | quantity | Extract numerical value from free text using regex: first attempt to extract meaningful dose values (see end_datetime logic), then any value. In case of multiple matches, only first is taken. | >95% of source strings can be parsed as numbers using regular expressions, however some might not be particularly meaningful. |
| days_supply | |||
| sig | |||
| route_concept_id | |||
| lot_number | |||
| provider_id | |||
| visit_occurrence_id | |||
| visit_detail_id | |||
| drug_source_value | dmd_code read_2 drug_name | ||
| drug_source_concept_id | dmd_code read_2 drug_name | ||
| route_source_value | |||
| dose_unit_source_value | |||
| data_source | data_provider | Map as “GP-“ + number found in data_provider, e.g. GP-1, GP-2, GP-3, or GP-4 |