Use index date for prescribed medications

    * the start date of list_size analyses should be after INDEX_DATE
    * medications which are prescribed before INDEX_DATE should not appear at all in
      list_analyses

Author: madwort

openprescribing/web/api.py

@@ -18,20 +18,27 @@
 # allow this to be configured by the user, or calculated directly from the data.
 DATE_COUNT = 96
 
+# This is the first month that we have monthly list size updates for.
+INDEX_DATE = "2017-04-01"
+
 # The number of individual medications shown as their own band in the "by medication"
 # stacked area chart.  Any further medications are summed into a single "Other" band.
 MEDICATIONS_TOP_N = 10
 
+PRESENTATIONS_PRESCRIBED_AFTER_INDEX_DATE_SQL = f"""
+    SELECT bnf_code FROM presentation WHERE last_prescribed_date > '{INDEX_DATE}'
+"""
+
 # Selects medications that have been prescribed: VMPs/AMPs whose BNF code appears in the
 # prescribing data, plus the parent VMPs of any prescribed AMPs.
-PRESCRIBED_MEDICATIONS_SQL = """
+PRESCRIBED_MEDICATIONS_SQL = f"""
     SELECT * FROM medications
-    WHERE bnf_code IN (SELECT bnf_code FROM presentation)
+    WHERE bnf_code IN ({PRESENTATIONS_PRESCRIBED_AFTER_INDEX_DATE_SQL})
     OR (
         NOT is_amp
         AND id IN (
             SELECT DISTINCT vmp_id FROM medications
-            WHERE is_amp AND bnf_code IN (SELECT bnf_code FROM presentation)
+            WHERE is_amp AND bnf_code IN ({PRESENTATIONS_PRESCRIBED_AFTER_INDEX_DATE_SQL})
         )
     )
 """

tests/utils/data_utils.py

@@ -1,6 +1,8 @@
 import datetime
+from enum import Enum
 
 from openprescribing.data.models import BNFCode, Org, OrgRelation
+from openprescribing.web.api import INDEX_DATE
 
 
 def generate_test_data(rxdb, bnf_codes):
@@ -60,3 +62,17 @@ def generate_test_data(rxdb, bnf_codes):
     )
 
     return {"list_size_data": list_size_data, "prescribing_data": prescribing_data}
+
+
+class DateRelativeToIndexDate(Enum):
+    BEFORE = 1
+    AFTER = 2
+
+
+def default_date_relative_to_index_date(relation_to_index_date):
+    if relation_to_index_date == DateRelativeToIndexDate.BEFORE:
+        prescribing_datetime_delta = datetime.timedelta(weeks=-2)
+    else:
+        prescribing_datetime_delta = datetime.timedelta(weeks=2)
+
+    return str(datetime.date.fromisoformat(INDEX_DATE) + prescribing_datetime_delta)

tests/utils/rxdb_utils.py

@@ -14,6 +14,10 @@
     CursorCacheKeyWrapper,
 )
 from openprescribing.data.utils.duckdb_utils import escape
+from tests.utils.data_utils import (
+    DateRelativeToIndexDate,
+    default_date_relative_to_index_date,
+)
 
 
 PRESCRIBING_SOURCE_SCHEMA = pyarrow.schema(
@@ -33,7 +37,6 @@
 PRESCRIBING_SOURCE_DEFAULTS = {
     "bnf_code": "",
     "snomed_code": 0,
-    "date": datetime.date(2000, 1, 1),
     "practice_code": "",
     "quantity_value": 0.0,
     "items": 0,
@@ -125,6 +128,12 @@ def rxdb_ingest(conn, prescribing_data=(), list_size_data=()):
     If tests need to supply their own BNF code changes, we should add a bnf_code_changes
     parameter to this function.
     """
+
+    # Set our default date to be after api's INDEX_DATE
+    PRESCRIBING_SOURCE_DEFAULTS["date"] = default_date_relative_to_index_date(
+        DateRelativeToIndexDate.AFTER
+    )
+
     prescribing_data = prepare_data(prescribing_data, PRESCRIBING_SOURCE_DEFAULTS)
     list_size_data = prepare_data(list_size_data, LIST_SIZE_SOURCE_DEFAULTS)
     prescribing_source = pyarrow.Table.from_pylist(

tests/web/test_api.py

@@ -4,6 +4,10 @@
 import pytest
 
 from openprescribing.web import api
+from tests.utils.data_utils import (
+    DateRelativeToIndexDate,
+    default_date_relative_to_index_date,
+)
 from tests.utils.ingest_utils import ingest_dmd_bnf_map_data, ingest_dmd_data
 
 
@@ -216,13 +220,27 @@ def test_prescribing_medications_groups_other(client, sample_data, monkeypatch):
     assert "Other" in medications
 
 
-def test_metadata_medications(client, rxdb, settings, tmp_path):
-    rxdb.ingest([{"bnf_code": "1106000X0AAA4A4"}])
+@pytest.mark.parametrize(
+    "prescribing_date_relative_to_index_date",
+    [DateRelativeToIndexDate.BEFORE, DateRelativeToIndexDate.AFTER],
+)
+def test_metadata_medications(
+    client, rxdb, settings, tmp_path, prescribing_date_relative_to_index_date
+):
+    prescribing_date = default_date_relative_to_index_date(
+        prescribing_date_relative_to_index_date
+    )
+
+    rxdb.ingest([{"bnf_code": "1106000X0AAA4A4", "date": str(prescribing_date)}])
     ingest_dmd_data(settings, tmp_path)
     ingest_dmd_bnf_map_data(settings, tmp_path)
     rsp = client.get("/api/metadata/medications/")
     payload = rsp.json()
 
+    if prescribing_date_relative_to_index_date == DateRelativeToIndexDate.BEFORE:
+        assert [] == payload["medications"]
+        return
+
     assert {
         "id": 9393711000001102,
         "bnf_code": "1106000X0AAA4A4",
@@ -247,7 +265,16 @@ def test_metadata_medications(client, rxdb, settings, tmp_path):
     } in payload["medications"]
 
 
-def test_metadata_dmd(client, rxdb, medications):
+@pytest.mark.parametrize(
+    "prescribing_date_relative_to_index_date",
+    [DateRelativeToIndexDate.BEFORE, DateRelativeToIndexDate.AFTER],
+)
+def test_metadata_dmd(
+    client, rxdb, medications, prescribing_date_relative_to_index_date
+):
+    prescribing_date = default_date_relative_to_index_date(
+        prescribing_date_relative_to_index_date
+    )
     # Two VMPs with distinct VTMs, ingredients and form/routes, plus an AMP belonging to
     # the first VMP; only the first VMP (and hence its AMP) is then prescribed.
     medications.add_rows(
@@ -273,10 +300,15 @@ def test_metadata_dmd(client, rxdb, medications):
             },
         ]
     )
-    rxdb.ingest([{"bnf_code": "1001030U0AAABAB"}])
+    rxdb.ingest([{"bnf_code": "1001030U0AAABAB", "date": prescribing_date}])
 
     payload = client.get("/api/metadata/dmd/").json()
 
+    if prescribing_date_relative_to_index_date == DateRelativeToIndexDate.BEFORE:
+        assert payload["vmp"] == []
+        assert payload["amp"] == []
+        return
+
     # Only the prescribed VMP, its AMP, and the VTM, ingredient and form/route they
     # relate to are returned; the unprescribed VMP's objects are excluded.
     assert payload["vmp"] == [{"id": 1, "vtm_id": 1, "name": "Prescribed VMP"}]
@@ -286,15 +318,30 @@ def test_metadata_dmd(client, rxdb, medications):
     assert [record["descr"] for record in payload["ont_form_route"]] == ["tablet.oral"]
 
 
-def test_metadata_bnf(client, rxdb, bnf_codes, medications):
+@pytest.mark.parametrize(
+    "prescribing_date_relative_to_index_date",
+    [DateRelativeToIndexDate.BEFORE, DateRelativeToIndexDate.AFTER],
+)
+def test_metadata_bnf(
+    client, rxdb, bnf_codes, medications, prescribing_date_relative_to_index_date
+):
+    prescribing_date = default_date_relative_to_index_date(
+        prescribing_date_relative_to_index_date
+    )
+
     # The bnf_codes fixture provides the BNF hierarchy; we also need to link a VMP to a
     # generic methotrexate presentation and prescribe it so that appears in the
     # medications view.
     medications.add_rows([{"bnf_code": "1001030U0BDAAAB"}])
-    rxdb.ingest([{"bnf_code": "1001030U0BDAAAB"}])
+    rxdb.ingest([{"bnf_code": "1001030U0BDAAAB", "date": prescribing_date}])
 
     rsp = client.get("/api/metadata/bnf/")
     payload = rsp.json()
+
+    if prescribing_date_relative_to_index_date == DateRelativeToIndexDate.BEFORE:
+        assert payload["bnf"] == []
+        return
+
     assert {
         "code": "10",
         "level": 1,