Slot: Linkage Strategy (linkage_strategy)

How a gridded value is attached to a patient location.

Tier: core

Why this slot matters

The strategy determines which grid cells or stations contribute to a patient's value: point extraction, buffer aggregation, and population weighting can assign materially different exposures to the same address. Without it the person-level value cannot be reproduced or compared across studies — this is the "linkage descriptor" gap named by the GECC/EIRENE forum.

In plain terms

Environmental data comes as a map of values, but health data belongs to people. This slot records the rule used to pick a person's value off that map — for example reading the value exactly at their home, or averaging the values in a circle around it.

URI: envar:slot/linkage_strategy

Applicable Classes

Name	Description	Modifies Slot
LinkageMethod	How a gridded environmental value gets attached to a patient: the resolution ...	yes

Properties

Type and Range

Property	Value
Range	LinkageStrategyEnum
Domain Of	LinkageMethod

Cardinality and Requirements

Property	Value

Examples

Value
point_extraction_at_residence
population_weighted_area_to_residence

Identifier and Mapping Information

Annotations

property	value
tier	core
justification	The strategy determines which grid cells or stations contribute to a patient's value: point extraction, buffer aggregation, and population weighting can assign materially different exposures to the same address. Without it the person-level value cannot be reproduced or compared across studies — this is the "linkage descriptor" gap named by the GECC/EIRENE forum.
explanation	Environmental data comes as a map of values, but health data belongs to people. This slot records the rule used to pick a person's value off that map — for example reading the value exactly at their home, or averaging the values in a circle around it.
covered_by	None

Schema Source

• from schema: https://w3id.org/linkml/microschemas/envar

Mappings

Mapping Type	Mapped Value
self	envar:linkage_strategy
native	envar:linkage_strategy

LinkML Source

name: linkage_strategy
annotations:
  tier:
    tag: tier
    value: core
  justification:
    tag: justification
    value: 'The strategy determines which grid cells or stations contribute to a patient''s
      value: point extraction, buffer aggregation, and population weighting can assign
      materially different exposures to the same address. Without it the person-level
      value cannot be reproduced or compared across studies — this is the "linkage
      descriptor" gap named by the GECC/EIRENE forum.'
  explanation:
    tag: explanation
    value: Environmental data comes as a map of values, but health data belongs to
      people. This slot records the rule used to pick a person's value off that map
      — for example reading the value exactly at their home, or averaging the values
      in a circle around it.
  covered_by:
    tag: covered_by
    annotations:
      omop_gaia:
        tag: omop_gaia
        annotations:
          extent:
            tag: extent
            value: partial
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: working.spatial_join_exposure SQL (st_within with a hard-coded
              buffer); spatial_join_log.txt
          note:
            tag: note
            value: 'GAIA''s linkage strategy is only implicit in the st_within SQL
              join semantics, not exposed as a documented structured slot. Conservative:
              partial.'
      degauss:
        tag: degauss
        annotations:
          extent:
            tag: extent
            value: absent
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: DeGAUSS carries no structured linkage-strategy slot; the point-extraction
              rule is implicit.
      amadeus:
        tag: amadeus
        annotations:
          extent:
            tag: extent
            value: absent
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: Amadeus carries no linkage-strategy slot; the value is extracted
              at request coordinates with no recorded strategy.
      cher:
        tag: cher
        annotations:
          extent:
            tag: extent
            value: partial
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: table_column_dictionary column tagged Spatial – Primary + reference
              to boundaries schema
          note:
            tag: note
            value: 'C-HER''s Spatial tags and boundaries-schema references encode
              a spatial join relationship, though not EnVar''s linkage-strategy enum.
              Conservative: partial.'
      codata:
        tag: codata
        annotations:
          extent:
            tag: extent
            value: out_of_layer
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: The gridded-to-patient linkage strategy is an instance-layer derivation
              choice, outside CODATA's conceptual variable layer.
description: How a gridded value is attached to a patient location.
title: Linkage Strategy
examples:
- value: point_extraction_at_residence
  description: extract the grid-cell value at the geocoded residence (Daymet tmax
    scenario)
- value: population_weighted_area_to_residence
  description: population-weighted aggregation over the residence tract (ACAG PM2.5
    scenario)
from_schema: https://w3id.org/linkml/microschemas/envar
rank: 1000
domain_of:
- LinkageMethod
range: LinkageStrategyEnum