Optum EHR Drug Exposure End Date Imputation
Due to the nature of EHR data most days_supply fields are input as zero. Martijn developed a method during the LEGEND-Hypertension study that will impute the value and updated the DRUG_EXPOSURE_END_DATE.
- Take the most frequent non-zero exposure length per drug_concept_id as the default, if that frequency is greater than 10.
- For all drug exposures with zero length use the default length defined in step 1 and update the DRUG_EXPOSURE_END_DATE using the formula DRUG_EXPOSURE_END_DATE = DRUG_EXPOSURE_START_DATE + imputed DAYS_SUPPLY - 1
- This is true unless the DAYS_SUPPLY is greater than 365 days. In that case, the DRUG_EXPOSURE_END_DATE is reverted back to equal the DRUG_EXPOSURE_START_DATE to handle implausible values and prevent them from making the DRUG_ERAs too long.
Code he uses to do this: https://github.com/schuemie/MethodsLibraryPleEvaluation/blob/master/inst/sql/sql_server/ExposureLengthImputation.sql
We apply this imputation strategy after data has been moved to the DRUG_EXPOSURE table from the STEM table as detailed below. Once completed the DRUG_ERA logic is run to create DRUG_ERAs using the imputed dates.
Optum EHR Days Supply Filtering
Some records from source tables for cdm.DRUG_EXPOSURE have very high days_supply values, which are likely inaccurate (most states in the US require prescriptions to be renewed at least annually). Reocrds with days_supply >= 365 are excluded from cdm.DRUG_EXPOSURE.
Table name: drug_exposure
| Destination Field | Source field | Logic | Comment field |
|---|---|---|---|
| drug_exposure_id | id | ||
| person_id | person_id | ||
| drug_concept_id | concept_id | ||
| drug_exposure_start_date | start_date | ||
| drug_exposure_start_datetime | start_datetime | ||
| drug_exposure_end_date | end_date | If zero, apply imputation strategy | |
| drug_exposure_end_datetime | end_datetime | ||
| verbatim_end_date | |||
| drug_type_concept_id | type_concept_id | ||
| stop_reason | stop_reason | ||
| refills | refills | ||
| quantity | quantity | Allowed number of refills up to 24. if this number is higher, set drug_expusure.refills = NULL | |
| days_supply | days_supply | ||
| sig | sig | ||
| route_concept_id | route_concept_id | ||
| lot_number | lot_number | ||
| provider_id | provider_id | ||
| visit_occurrence_id | visit_occurrence_id | ||
| visit_detail_id | |||
| drug_source_value | source_value | ||
| drug_source_concept_id | source_concept_id | ||
| route_source_value | route_source_value | ||
| dose_unit_source_value | dose_unit_source_value |
Change log
- 12-Dec-2023 Set max allowed refills up to 24