CALIBER Bleeding Academic Research Consortium bleeding definition
Name barc_composite
Chapter Diseases of the blood/Bleeding
Definition
CALIBER variable for bleeding according to BARC criteria (Bleeding Academic Research Consortium http://circ.ahajournals.org/content/123/23/2736.full), for use in studies on anticoagulation, atrial fibrillation etc.

This definition was created for studies on atrial fibrillation and coronary disease. If it is used in younger patients, obstetric and gynaelogical bleeds should be further classified and reviewed by a subject specialist.

BARC category 1 bleeds (minor bleeding) do not cause the patient to seek healthcare and would generally not be recorded in CALIBER.  

Currently only OPCS codes are used for identifying CABG and type 4 bleeds, because the criteria state that the bleed must be within 48h after CABG. Dates in CPRD and HES are less certain, so these data sources are not used to identify type 4 bleeds.

This algorithm can be updated if more data sources are available, e.g. data on blood transfusions, or diagnostic information in hospital inpatient records.
Data Type Categorical
Data sources GPRD, HES, ONS
Repeated Yes
Valid event date range -
Agreed 30/09/2013 (Revision 1)
Category Definition
1 BARC 2 (Overt, actionable sign of haemorrhage)
2 BARC 3a (Transfusion or haemoglobin drop)
3 BARC 3b (Bleeding with severe blood loss or requiring surgical intervention)
5 BARC 3c (Intracranial or intraocular bleed)
7 BARC 4 (Coronary Artery Bypass Graft related bleeding)
8 BARC 5 (Fatal bleeding)
Implementation
Constituent variables:
- bleeding_ons
- barc_gprd
- barc_hes
- barc_opcs
- cabg_opcs

STEP 1: Identify bleeding events

A bleeding event is defined as:
- Any entry in ONS with an ICD-10 code in the bleeding_ons codelist as the underlying cause of death
- Any entry in the GPRD clinical table with Read code in the barc_gprd codelist
- Any entry in HES (primary or secondary) with ICD-10 code in the barc_hes codelist
- Any entry in OPCS with OPCS code in the barc_opcs codelist

Create a list of bleeding events with source, category and date.
Create a list of CABG events in OPCS with date

STEP 2: Classify each bleeding event

IF source is ONS, barc_composite = 8 [BARC 5, Fatal]

ELSE IF source is OPCS and there is a CABG event
    (cabg_opcs category 2 or 3) 0-2 days before bleeding event THEN:
    IF barc_opcs = 4 or 6 THEN barc_composite = 7 [BARC 4]
    ELSE barc_composite = barc_opcs

ELSE IF source is OPCS:
    IF barc_opcs = 4 THEN barc_composite = 3 [BARC 3b]
    ELSE IF barc_opcs = 6 THEN barc_composite = 5 [BARC 3c]
    ELSE barc_composite = barc_opcs

ELSE IF source is HES:
    barc_composite = barc_hes

ELSE barc_composite = barc_gprd

STEP 3: When aggregating events, select the most severe BARC category

Use the most severe code on a particular date or within the date range of interest
e.g. if a patient had a BARC 2 bleed recorded in GPRD which was fatal, classify it
as 5 rather than 2.
Codelist version
Codelist authors
Creation date
Warning! Unless explicitly noted otherwise, three-digit ICD10/OPCS4 codes also include all codes below them.
Category (code) Clinical code Clinical term Datasource lookup
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