feat: add get_patient_indication_groups() for Snowflake-direct GP lookup (Task 1.1)

- Add CLUSTER_MAPPING_SQL constant embedding full snomed_indication_mapping_query.sql
- Add get_patient_indication_groups() function that queries Snowflake directly
- Uses QUALIFY ROW_NUMBER() to get most recent diagnosis per patient
- Returns DataFrame with PatientPseudonym, Search_Term, EventDateTime
- Handles edge cases: empty list, Snowflake unavailable
- Batch processing with configurable batch_size (default 500)
- Comprehensive logging for match statistics
This commit is contained in:
Andrew Charlwood
2026-02-05 17:03:00 +00:00
parent 99bab08402
commit 1a817b8257
3 changed files with 474 additions and 610 deletions
+92 -111
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@@ -1,25 +1,25 @@
# Implementation Plan - Direct SNOMED Indication Mapping
# Implementation Plan - Indication-Based Pathway Charts
## Project Overview
Extend the pathway analysis application to use direct SNOMED code matching from GP records to:
1. **Improve directorate assignment** - Use diagnosis-based directorate as primary method
2. **Add indication-based icicle chart** - New chart type showing Trust → Search_Term → Drug → Pathway
### Data Source
`data/drug_snomed_mapping_enriched.csv` - 163K rows mapping:
- Drug → Indication → TA_ID → Search_Term → SNOMEDCode → PrimaryDirectorate
Extend the pathway analysis application to show indication-based icicle charts alongside directory-based charts. Patient diagnoses are matched from GP records using SNOMED cluster codes.
### Key Design Decisions
| Aspect | Decision |
|--------|----------|
| Primary directorate method | Diagnosis-based (SNOMED match → PrimaryDirectorate) |
| Fallback | department_identification() chain |
| Grouping level | `Search_Term` column (187 unique values) |
| Chart types | Two: "By Directory" and "By Indication" (user toggle) |
| SNOMED source | Query `ClinicalCodingClusterSnomedCodes` clusters directly in Snowflake |
| Grouping level | `Search_Term` from cluster mapping (~148 conditions) |
| Chart types | Two: "By Directory" (existing) and "By Indication" (new toggle) |
| No-match display | Show assigned directorate in indication chart (mixed labels) |
| Multiple matches | Use most recent SNOMED code by GP record date |
| Data storage | SQLite table `ref_drug_snomed_mapping`, accessed at ingestion |
| Data storage | No local SNOMED mapping — query Snowflake at refresh time |
### SNOMED Cluster Query
The `snomed_indication_mapping_query.sql` file contains the master query:
- Maps Search_Term → Cluster_ID for ~148 conditions
- Joins `ClinicalCodingClusterSnomedCodes` to get SNOMED codes per cluster
- Includes explicit manual mappings for conditions not in clusters
- Returns: Search_Term, SNOMEDCode, SNOMEDDescription
## Quality Checks
@@ -39,101 +39,62 @@ python -m reflex compile
---
## Phase 1: Data Infrastructure
## Phase 1: Snowflake Integration
### 1.1 Create SQLite Table for SNOMED Mapping
- [x] Add `REF_DRUG_SNOMED_MAPPING_SCHEMA` to `data_processing/schema.py`:
- Columns: drug_name, indication, ta_id, search_term, snomed_code, snomed_description, cleaned_drug_name, primary_directorate, all_directorates
- Index on: cleaned_drug_name, snomed_code, search_term
- [x] Add `create_drug_snomed_mapping_table()` helper function
- [x] Add to `ALL_TABLES_SCHEMA` and migration
- [x] Verify: `python -m data_processing.migrate` creates table
### 1.1 Create Indication Lookup Query
- [x] Add `get_patient_indication_groups()` function to `data_processing/diagnosis_lookup.py`:
- Takes: list of patient pseudonyms (PseudoNHSNoLinked values)
- Uses the cluster query from `snomed_indication_mapping_query.sql` as a CTE
- Joins with `PrimaryCareClinicalCoding` to find patients with matching diagnoses
- Returns: DataFrame with PatientPseudonym, Search_Term, EventDateTime
- Uses most recent match per patient (ORDER BY EventDateTime DESC)
- [x] Handle edge cases: Snowflake unavailable, empty patient list
- [ ] Verify: Function returns expected Search_Terms for test patients
### 1.2 Load Enriched Mapping Data
- [x] Create `data_processing/load_snomed_mapping.py` script:
- Read `data/drug_snomed_mapping_enriched.csv`
- Insert into `ref_drug_snomed_mapping` table
- Log: row count, unique drugs, unique search terms
- [x] Add CLI entry point: `python -m data_processing.load_snomed_mapping`
- [x] Verify: Query confirms 163K+ rows, 187 search terms
### 1.3 Extend Diagnosis Lookup Module
- [x] Add `get_drug_snomed_codes(drug_name)` to `diagnosis_lookup.py`:
- Query `ref_drug_snomed_mapping` for all SNOMED codes for a drug
- Return list of DrugSnomedMapping(snomed_code, snomed_description, search_term, primary_directorate, indication, ta_id)
- [x] Add `patient_has_indication_direct(patient_pseudonym, snomed_codes, connector)`:
- Query `PrimaryCareClinicalCoding` directly for exact SNOMED code matches
- Return most recent match by EventDateTime
- Return: DirectSnomedMatchResult(matched_code, search_term, primary_directorate, event_date) or unmatched
- [x] Verify: Tested with ADALIMUMAB (1320 mappings, 10 Search_Terms), RANIBIZUMAB (104 mappings), case-insensitivity
### 1.2 Update Data Pipeline to Include Indications
- [ ] Modify `cli/refresh_pathways.py` to call indication lookup during refresh:
- After fetching HCD data, extract unique PseudoNHSNoLinked values
- Call `get_patient_indication_groups()` with patient list
- Create `indication_df` mapping UPID → Indication_Group
- For patients with no GP match: Indication_Group = fallback directorate
- [ ] Log coverage: X% diagnosis-matched, Y% fallback
- [ ] Verify: indication_df has correct structure for pathway processing
---
## Phase 2: Pathway Processing Updates
## Phase 2: Schema & Processing Updates
### 2.1 Update Directorate Assignment Logic
- [x] Modify `tools/data.py` `department_identification()` or create wrapper:
- Add `get_directorate_from_diagnosis(upid, drug_name, connector)` function
- Logic: Try diagnosis-based first → fallback to department_identification()
- Return: (directorate, source) where source is "DIAGNOSIS" or "FALLBACK"
- [x] Track assignment source for metrics (how many diagnosis-based vs fallback)
- [x] Verify: Test with sample patient data
### 2.1 Add Chart Type Support to Schema
- [x] Add `chart_type` column to `pathway_nodes` table (ALREADY DONE)
- [x] Update UNIQUE constraint to include chart_type (ALREADY DONE)
- [x] Add indexes for chart_type filtering (ALREADY DONE)
- [ ] Verify: Existing migration works correctly
### 2.2 Add Chart Type Support to Schema
- [x] Add `chart_type` column to `pathway_nodes` table:
- Values: "directory" (existing), "indication" (new)
- Update schema in `data_processing/schema.py`
- [x] Update UNIQUE constraint to include chart_type: `UNIQUE(date_filter_id, chart_type, ids)`
- [x] Add `idx_pathway_nodes_chart_type` index for filtering by chart type
- [x] Add `migrate_pathway_nodes_chart_type()` function for existing databases
- [x] Update `initialize_database()` to run migration automatically
- [x] Verify: Migration adds column, existing data defaults to "directory"
### 2.2 Create Indication Pathway Processing
- [x] Add `generate_icicle_chart_indication()` to `pathway_analyzer.py` (ALREADY DONE)
- [x] Add `process_indication_pathway_for_date_filter()` to `pathway_pipeline.py` (ALREADY DONE)
- [x] Add `extract_indication_fields()` for denormalized columns (ALREADY DONE)
- [x] Update `convert_to_records()` with `chart_type` parameter (ALREADY DONE)
- [ ] Verify: Code compiles, imports work correctly
### 2.3 Create Indication Pathway Processing
- [x] Add `process_indication_pathway_for_date_filter()` to `pathway_pipeline.py`:
- Group by: Trust → Search_Term → Drug → Pathway
- For unmatched patients: use directorate name as Search_Term fallback
- Output: Same structure as directory pathways but with indication grouping
- [x] Add `generate_icicle_chart_indication()` to `pathway_analyzer.py`:
- Variant of `generate_icicle_chart()` that uses indication_df instead of directory_df
- Takes `indication_df` parameter mapping UPID → Indication_Group
- [x] Add `extract_indication_fields()` for denormalized columns:
- Extract: trust_name, search_term (or fallback_directorate), drug_sequence
- [x] Update `convert_to_records()` to include `chart_type` parameter
- [x] Add `ChartType` type alias ("directory" | "indication")
- [x] Verify: Code compiles, imports work correctly
### 2.3 Update Refresh Command for Dual Charts
- [x] Add `--chart-type` argument: "all", "directory", "indication" (ALREADY DONE)
- [ ] Update indication processing to use new `get_patient_indication_groups()`:
- Replace `batch_lookup_indication_groups()` with the new Snowflake-direct approach
- Pass indication_df to `process_indication_pathway_for_date_filter()`
- [ ] Process all 6 date filters for both chart types
- [ ] Verify: Both chart types generate pathway data
---
## Phase 3: CLI & Data Refresh Updates
## Phase 3: Test Full Pipeline
### 3.1 Update Refresh Command for Dual Chart Types
- [x] Modify `cli/refresh_pathways.py`:
- Process both "directory" and "indication" chart types
- For each of 6 date filters: generate 2 chart datasets
- Total: 12 pathway datasets (6 dates × 2 chart types)
- [x] Add `--chart-type` argument: "all" (default), "directory", "indication"
- [x] Update progress logging to show both chart types
- [x] Verify: Dry run shows both chart types being processed (Task 3.2 complete)
### 3.2 Integrate Diagnosis-Based Directorate in Pipeline
- [x] Add `batch_lookup_indication_groups()` to `diagnosis_lookup.py`:
- Batch lookup SNOMED matches for all patients (500 patients per batch)
- Returns DataFrame with UPID, Indication_Group, Source columns
- Source is "DIAGNOSIS" (GP match found) or "FALLBACK" (no match)
- [x] Update `cli/refresh_pathways.py` indication processing:
- Call `batch_lookup_indication_groups()` before processing indication charts
- Build `indication_df` for use with `process_indication_pathway_for_date_filter()`
- Process all 6 date filters with indication grouping
- [x] Handle Snowflake connection for GP record queries (batched for performance)
- [x] Log coverage: X% diagnosis-matched, Y% fallback
- [ ] Verify: Test refresh with --dry-run, check coverage stats
### 3.3 Test Full Refresh Pipeline
- [~] Run `python -m cli.refresh_pathways` with real data
- [ ] Verify pathway_nodes table has both chart_type values
- [ ] Verify indication chart has expected hierarchy (Trust → SearchTerm → Drug)
- [ ] Verify unmatched patients appear with directorate fallback label
### 3.1 Test Refresh with Real Data
- [ ] Run `python -m cli.refresh_pathways --chart-type all` with Snowflake
- [ ] Verify pathway_nodes table has both chart_type values:
- `SELECT chart_type, COUNT(*) FROM pathway_nodes GROUP BY chart_type`
- [ ] Verify indication hierarchy: Trust → Search_Term → Drug → Pathway
- [ ] Verify unmatched patients show with directorate fallback label
- [ ] Document: Processing time, record counts, coverage percentages
---
@@ -166,20 +127,14 @@ python -m reflex compile
## Phase 5: Validation & Documentation
### 5.1 Measure Coverage Improvement
- [ ] Compare match rates: cluster-only vs cluster+direct SNOMED
- [ ] Generate report: % of patients with diagnosis-based directorate
- [ ] Identify drugs with best/worst coverage improvement
- [ ] Document results in progress.txt
### 5.2 End-to-End Validation
### 5.1 End-to-End Validation
- [ ] Run full app with both chart types
- [ ] Verify chart toggle works correctly
- [ ] Verify filter interactions (drugs, directorates) work for both types
- [ ] Verify KPIs update correctly for both chart types
- [ ] Test at multiple viewport sizes
### 5.3 Update Documentation
### 5.2 Update Documentation
- [ ] Update CLAUDE.md with new architecture
- [ ] Document new CLI arguments
- [ ] Document chart_type toggle behavior
@@ -193,7 +148,7 @@ All tasks marked `[x]` AND:
- [ ] App compiles without errors (`reflex compile` succeeds)
- [ ] Both chart types generate pathway data (12 total: 6 dates × 2 types)
- [ ] Chart type toggle switches between Directory and Indication views
- [ ] Diagnosis-based directorate is primary method with fallback working
- [ ] GP diagnosis matching works via Snowflake cluster query
- [ ] Unmatched patients show in indication chart with directorate fallback label
- [ ] Coverage metrics logged (% diagnosis-matched vs fallback)
- [ ] All filters work correctly for both chart types
@@ -203,6 +158,35 @@ All tasks marked `[x]` AND:
## Reference
### SNOMED Cluster Query Structure
```sql
-- From snomed_indication_mapping_query.sql
WITH SearchTermClusters AS (
SELECT Search_Term, Cluster_ID FROM (VALUES
('rheumatoid arthritis', 'eFI2_InflammatoryArthritis'),
('macular degeneration', 'CUST_ICB_VISUAL_IMPAIRMENT'),
-- ... ~148 mappings
) AS t(Search_Term, Cluster_ID)
),
ClusterCodes AS (
SELECT stc.Search_Term, c."SNOMEDCode", c."SNOMEDDescription"
FROM SearchTermClusters stc
JOIN DATA_HUB.PHM."ClinicalCodingClusterSnomedCodes" c
ON stc.Cluster_ID = c."Cluster_ID"
WHERE c."SNOMEDCode" IS NOT NULL
),
ExplicitCodes AS (
-- Manual mappings for conditions not in clusters
SELECT Search_Term, SNOMEDCode, SNOMEDDescription FROM (VALUES
('ankylosing spondylitis', '162930007', 'Manual mapping'),
-- ...
) AS t(Search_Term, SNOMEDCode, SNOMEDDescription)
)
SELECT * FROM ClusterCodes
UNION ALL
SELECT * FROM ExplicitCodes
```
### Current Pathway Hierarchy (Directory-based)
```
Root (N&W ICS)
@@ -226,20 +210,17 @@ Root (N&W ICS)
| File | Purpose |
|------|---------|
| `data_processing/schema.py` | SQLite schema for ref_drug_snomed_mapping |
| `data_processing/diagnosis_lookup.py` | Direct SNOMED lookup functions |
| `snomed_indication_mapping_query.sql` | Master SNOMED cluster query |
| `data_processing/diagnosis_lookup.py` | GP diagnosis lookup functions |
| `data_processing/pathway_pipeline.py` | Indication pathway processing |
| `cli/refresh_pathways.py` | CLI for dual chart type refresh |
| `pathways_app/pathways_app.py` | Reflex UI with chart type toggle |
| `data/drug_snomed_mapping_enriched.csv` | Source mapping data |
### Expected Data Volumes
| Metric | Expected |
|--------|----------|
| SNOMED mapping rows | ~163K |
| Unique Search_Terms | 187 |
| Unique drugs | ~364 |
| Search_Term conditions | ~148 (from cluster mapping) |
| Pathway nodes (directory, per date filter) | ~300 |
| Pathway nodes (indication, per date filter) | ~400-600 (more granular) |
| Total pathway nodes (6 dates × 2 types) | ~4,000-5,000 |