Enhancement: Add Value as String Attribute for Drug.Sig and Measurement.value_source_value

[TomWhite-MedStar]

Expected behavior

Since there Atlas has cohort design are Value as String options for Observations, I presumed they would also be available for Drugs and Measurements.

Use cases include:

• Query SIG to identify indication for a drug. For example, we're analyzing use of paralytics in rapid sequence intubation, and that paralytic has multiple indications, so we want to filter our data just to the drug exposures for the desired indication (our sig field includes the indication).
• Query SIG to distinguish between medications administered and those handed to patients as discharge medications (our sig field includes nursing instructions). For example, we are increasing orders for Narcan to prevent opioid overdoses, and the structured data can make it look as thought a dose of Narcan was administered when instead the nurse handed the patient a Narcan take home kit. Although we could adjust our ETL to address this, the value of adding Value as String searches for SIG is that we have other situations where this confusion might exist, so adding the query ability to Atlas helps us identify ETL optimization opportunities without delaying the ability to generate insights from the existing data.
• Query Measurement value_source_value for specific strings. Many measurements have a limited set of answer options. We've created non-standard local vocabulary codes for the most common, but that is cumbersome for the potentially thousands of unique string values we'd like to track. Being able to query value_as_string would let us filter our measurements as desired without having to update our ETL or add tens of thousands of new local value codes.

Actual behavior

When adding attributes to Drug Exposure, there is no option to query the SIG:

By contrast, there is a Value as String search option for Observations:

Within that search, there is good flexibility of searching for strings that match (or don't) criteria:

Enhancement Details:

1. Add Value as String equivalent to query drug_exposure.sig
2. Add Valid as String equivalent to query measurement.value_source_value
3. Optionally augment Value as String options to include Regex Match and Not Regex Match
4. Optionally augment Value as String options to add In and Not In - so can have comma-separated list of criteria