add measures

analysis/measures_dm_reg_dataset.py

@@ -0,0 +1,74 @@
+from ehrql import INTERVAL, create_measures, months, case, when
+from ehrql.tables.tpp import (
+    practice_registrations,
+    patients,
+    clinical_events,
+    addresses,
+)
+from dm_reg_dataset import dm_cod
+
+measures = create_measures()
+measures.configure_dummy_data(population_size=100)
+measures.configure_disclosure_control(enabled=False)
+
+start_date = "2017-03-31"
+
+# Is patient registered to a GP practice? (Boolean variable)
+has_registration = practice_registrations.for_patient_on(
+    INTERVAL.end_date
+).exists_for_patient()
+
+# Select clinical events for measures interval
+selected_events = clinical_events.where(
+    clinical_events.date.is_on_or_between(
+        INTERVAL.start_date,
+        INTERVAL.end_date,
+    )
+)
+
+# Select clinical events with a diabetes diagnosis code (occurence - how many patients had a diabetes-coded clinical event during the interval)
+dm_occurence = selected_events.where(
+    selected_events.snomedct_code.is_in(dm_cod)
+).exists_for_patient()
+
+# Age band groupings
+age = patients.age_on(INTERVAL.start_date)
+age_band = case(
+    when((age >= 0) & (age < 20)).then("0-19"),
+    when((age >= 20) & (age < 40)).then("20-39"),
+    when((age >= 40) & (age < 60)).then("40-59"),
+    when((age >= 60) & (age < 80)).then("60-79"),
+    when(age >= 80).then("80+"),
+    when(age.is_null()).then("Missing"),
+)
+
+# IMD groupings
+imd = addresses.for_patient_on(INTERVAL.start_date).imd_rounded
+max_imd = 32844
+imd_quintile = case(
+    when((imd >= 0) & (imd < int(max_imd * 1 / 5))).then("1 (Most Deprived)"),
+    when(imd < int(max_imd * 2 / 5)).then("2"),
+    when(imd < int(max_imd * 3 / 5)).then("3"),
+    when(imd < int(max_imd * 4 / 5)).then("4"),
+    when(imd <= max_imd).then("5 (Least Deprived)"),
+    otherwise="Missing",
+)
+
+# Defining default denominators (as we are using the same denominator and interval for each measure here)
+measures.define_defaults(
+    denominator=(has_registration & (patients.age_on(INTERVAL.start_date) > 17)),
+    intervals=months(12).starting_on(start_date),
+)
+
+# This measure looks at the number of patients with a diabetes diagnosis code per interval
+measures.define_measure(name="dm_occurence", numerator=dm_occurence)
+
+# This measure looks at the number of patients with a diabetes diagnosis code per interval by age band
+measures.define_measure(
+    name="dm_occurence_by_age", numerator=dm_occurence, group_by={"age_band": age_band}
+)
+
+# This measure looks at the number of patients with a diabetes diagnosis code per interval by IMD
+measures.define_measure(
+    name="dm_occurence_by_imd", numerator=dm_occurence, group_by={"imd": imd_quintile}
+)