Introduction
This is a technical documentation for “factor-based” concept ranges. For the background of these ranges, refer to the main documentation.
The criteria field in the concept_reference_range table allows for the dynamic and flexible validation of observations based on various patient attributes.
Architecture
The key challenge in implementing this feature was to design a system that does not require extensive changes to the existing database structure while still being robust and flexible enough to handle a variety of criteria based on different patient factors.
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concept_reference_range: This table holds the absolute, critical, and normal ranges along with acriteriacolumn. Thecriteriacolumn contains a coded function that performs validation checks, such as those based on age or gender, using the Velocity engine for evaluationvelocity text expressions that evaluate to true or false.obs_reference_range: This table stores the validated reference ranges for observation numeric values that have been used in validation after the criteria have been applied.
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This design allows for easy updates and expansions of criteria without requiring changes to the underlying database schema.
Business Logic Flow
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Schema changes
This section details the new tables and relationships added to the OpenMRS data model to support factor-based concept ranges.
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Column Name | Data Type | Description |
|---|---|---|
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| Primary key. Unique identifier for each concept reference range. |
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| Foreign key linking to |
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| An expression that specifies conditions for when the reference range is applicable. |
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| The high critical for the concept. |
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| The high normal for the concept. |
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| The upper high absolute for the concept. |
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| The lower low critical for the concept. |
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| The lower low normal for the concept. |
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| The lower low absolute for the concept. |
RelationshipsRelationship:
1:N relationship with concept_numeric: A single concept can have multiple reference ranges based on different criteria.
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Column Name | Data Type | Description |
|---|---|---|
|
| Primary key. Unique identifier for each observation reference range. |
|
| Foreign key linking to the |
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| The high critical limit for the observation. |
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| The high normal limit for the observation. |
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| The high absolute limit for the observation. |
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| The low critical limit for the observation. |
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| The low normal limit for the observation. |
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| The low absolute limit for the observation. |
RelationshipsRelationship:
Has 1:1 relationship with obs: Each observation has one associated reference range.