Observational Health Data Sciences and Informatics

While v5 visit_occurrence table supports both date and time of event, other occurrence tables and exposure tables such as drug, condition, and procedure support only the date level. It is desirable to have the option to include specific time data for such occurrences.

We propose adding time field to the following tables

• Condition_Occurrence
• Procedure_Occurrence
• Drug_exposure
• Device_exposure
• Death

This would support handling data from ICU, Emergency Department, infusions, post-procedure care, etc where multiple events occur on the same day and sequence matters. This granularity would also support the incorporation of data generated from tracking devices.

Allow temporal operations finer than day without requiring recoding the OHDSI software, and consider allowing durations ===

1. Throughout the CDM tables, keep all *_DATE fields as is, still in DATE format. These are generally required, non-null fields.

2. For each *_DATE field, add a *_TIME field of type DATETIME = TIMESTAMP, and make those fields optional.

As above 1-2 and

3. Add a *_TIME_GRAN granularity field for each new DATETIME field, which would indicate year, month, day, hour, minute, or second as the timestamp's granularity. When a timestamp is filled in, it should be set to the first valid time in that indicated interval. E.g., 1990-12-01-00:00:00.000000 is the correct entry for December, 1990.

As above 1-2, optionally 3, and

4. Add a BIRTH_TIME timestamp column to the PERSON table to speed age calculations.

Independent of 1-4, it was suggested that all tables have *_START_DATE and *_END_DATE fields for all domains. This means PROCEDURE_OCCURRENCE, MEASUREMENT, OBSERVATION will be changing from having only 1 date to having 2 dates, and both would required (even if in some systems END_DATE = START_DATE).