anchor.diff:  CONDITION_ERA,condition_era_id,Yes,integer,,,Yes,No,,,,,
   CONDITION_ERA,person_id,Yes,integer,,,No,No,PERSON,PERSON_ID,,,
   CONDITION_ERA,condition_concept_id,Yes,integer,The Concept Id representing the Condition.,,No,Yes,CONCEPT,CONCEPT_ID,Condition,,
  -CONDITION_ERA,condition_era_start_date,Yes,datetime,"The start date for the Condition Era
  -constructed from the individual
  -instances of Condition Occurrences.
  -It is the start date of the very first
  -chronologically recorded instance of
  +CONDITION_ERA,condition_era_start_date,Yes,datetime,"The start date for the Condition Era
  +constructed from the individual
  +instances of Condition Occurrences.
  +It is the start date of the very first
  +chronologically recorded instance of
   the condition with at least 31 days since any prior record of the same Condition. ",,No,No,,,,,
  -CONDITION_ERA,condition_era_end_date,Yes,datetime,"The end date for the Condition Era
  -constructed from the individual
  -instances of Condition Occurrences.
  -It is the end date of the final
  -continuously recorded instance of the
  +CONDITION_ERA,condition_era_end_date,Yes,datetime,"The end date for the Condition Era
  +constructed from the individual
  +instances of Condition Occurrences.
  +It is the end date of the final
  +continuously recorded instance of the
   Condition.",,No,No,,,,,
  -CONDITION_ERA,condition_occurrence_count,No,integer,"The number of individual Condition
  -Occurrences used to construct the
  +CONDITION_ERA,condition_occurrence_count,No,integer,"The number of individual Condition
  +Occurrences used to construct the
   condition era.",,No,No,,,,,
   METADATA,metadata_concept_id,Yes,integer,,,No,Yes,CONCEPT,CONCEPT_ID,,,
   METADATA,metadata_type_concept_id,Yes,integer,,,No,Yes,CONCEPT,CONCEPT_ID,,,
  
positive.code: VISIT_DETAIL,care_site_id,No,integer,This field provides information about the Care Site where the Visit Detail took place.,There should only be one Care Site associated with a Visit Detail.,No,Yes,CARE_SITE,CARE_SITE_ID,,,
  VISIT_DETAIL,visit_detail_source_value,No,varchar(50),"This field houses the verbatim value from the source data representing the kind of visit detail that took place (inpatient, outpatient, emergency, etc.)","If there is information about the kind of visit detail in the source data that value should be stored here. If a visit is an amalgamation of visits from the source then use a hierarchy to choose the VISIT_DETAIL_SOURCE_VALUE, such as IP -> ER-> OP. This should line up with the logic chosen to determine how visits are created.",No,No,,,,,
  VISIT_DETAIL,visit_detail_source_concept_id,No,Integer,,If the VISIT_DETAIL_SOURCE_VALUE is coded in the source data using an OMOP supported vocabulary put the concept id representing the source value here.,No,Yes,CONCEPT,CONCEPT_ID,,,
  VISIT_DETAIL,admitting_source_value,No,Varchar(50),,"This information may be called something different in the source data but the field is meant to contain a value indicating where a person was admitted from. Typically this applies only to visits that have a length of stay, like inpatient visits or long-term care visits.",No,No,,,,,
  VISIT_DETAIL,admitting_source_concept_id,No,Integer,"Use this field to determine where the patient was admitted from. This concept is part of the visit domain and can indicate if a patient was admitted to the hospital from a long-term care facility, for example.","If available, map the admitted_from_source_value to a standard concept in the visit domain. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Visit&standardConcept=Standard&page=1&pageSize=15&query=).",No,Yes,CONCEPT,CONCEPT_ID,Visit,,
  VISIT_DETAIL,discharge_to_source_value,No,Varchar(50),,"This information may be called something different in the source data but the field is meant to contain a value indicating where a person was discharged to after a visit, as in they went home or were moved to long-term care. Typically this applies only to visits that have a length of stay of a day or more.",No,No,,,,,
  VISIT_DETAIL,discharge_to_concept_id,No,integer,"Use this field to determine where the patient was discharged to after a visit detail record. This concept is part of the visit domain and can indicate if a patient was discharged to home or sent to a long-term care facility, for example.","If available, map the DISCHARGE_TO_SOURCE_VALUE to a Standard Concept in the Visit domain. [Accepted Concepts](https://athena.ohdsi.org/search-terms/terms?domain=Visit&standardConcept=Standard&page=1&pageSize=15&query=).",No,Yes,CONCEPT,CONCEPT_ID,Visit,,
  VISIT_DETAIL,preceding_visit_detail_id,No,integer,Use this field to find the visit detail that occurred for the person prior to the given visit detail record. There could be a few days or a few years in between.,"The PRECEDING_VISIT_DETAIL_ID can be used to link a visit immediately preceding the current Visit Detail. Note this is not symmetrical, and there is no such thing as a ""following_visit_id"".",No,Yes,VISIT_DETAIL,VISIT_DETAIL_ID,,,
  
negative.code: DRUG_ERA,person_id,Yes,integer,,,No,Yes,PERSON,PERSON_ID,,,
  DRUG_ERA,drug_concept_id,Yes,integer,The Concept Id representing the specific drug ingredient.,,No,Yes,CONCEPT,CONCEPT_ID,Drug,Ingredient,
  DRUG_ERA,drug_era_start_date,Yes,datetime,,"The Drug Era Start Date is the start date of the first Drug Exposure for a given ingredient, with at least 31 days since the previous exposure. ",No,No,,,,,
  DRUG_ERA,drug_era_end_date,Yes,datetime,,"The Drug Era End Date is the end date of the last Drug Exposure. The End Date of each Drug Exposure is either taken from the field drug_exposure_end_date or, as it is typically not available, inferred using the following rules:
  For pharmacy prescription data, the date when the drug was dispensed plus the number of days of supply are used to extrapolate the End Date for the Drug Exposure. Depending on the country-specific healthcare system, this supply information is either explicitly provided in the day_supply field or inferred from package size or similar information.
  For Procedure Drugs, usually the drug is administered on a single date (i.e., the administration date).
  A standard Persistence Window of 30 days (gap, slack) is permitted between two subsequent such extrapolated DRUG_EXPOSURE records to be considered to be merged into a single Drug Era.",No,No,,,,,
  DRUG_ERA,drug_exposure_count,No,integer,,,No,No,,,,,
  DRUG_ERA,gap_days,No,integer,,"The Gap Days determine how many total drug-free days are observed between all Drug Exposure events that contribute to a DRUG_ERA record. It is assumed that the drugs are ""not stockpiled"" by the patient, i.e. that if a new drug prescription or refill is observed (a new DRUG_EXPOSURE record is written), the remaining supply from the previous events is abandoned.   The difference between Persistence Window and Gap Days is that the former is the maximum drug-free time allowed between two subsequent DRUG_EXPOSURE records, while the latter is the sum of actual drug-free days for the given Drug Era under the above assumption of non-stockpiling.",No,No,,,,,
  