Table 1:

Case definitions of heart failure used in the British Columbia node of the Canadian Primary Care Sentinel Surveillance Network

Definition	Conditions that must be met for a patient to be classified as having heart failure
1.1. Nova Scotia MaRNet-FP	≥ 1 ICD-9 diagnostic codes in EMR health condition table or EMR encounter diagnosis table (Appendix 3) OR Combination of ATC codes in the medication table in Appendix 4: (ACE inhibitor or ARB) and β-blocker and diuretic
1.2. Identical to 1.1 but also searching billings	≥ 1 ICD-9 diagnostic codes in EMR health condition table or EMR encounter diagnosis table or EMR billings table (Appendix 3) OR Combination of ATC codes in the medication table in Appendix 4: (ACE inhibitor or ARB) and β-blocker and diuretic
2.1. ICD-9 AND ATC codes Also revised ICD-9 and ATC codes	≥ 1 ICD-9 codes in EMR health condition table or EMR encounter diagnosis table or EMR billings table (Appendix 5) AND ≥ 1 ATC code for any ACE Inhibitor or any ARB or β-blocker or MRA or hydralazine (medication table in Appendix 4)
Definition 2.2 Subset of 2.1, diagnoses only	≥ 1 ICD-9 codes in EMR health condition table or EMR encounter diagnosis table or EMR billings table (Appendix 5)
Definition 2.3 Require 2 codes separated in time	≥ 2 ICD-9 codes (Appendix 5) in EMR health condition table, EMR encounter diagnosis table and EMR billings table combined, separated by ≥ 30 d
Definition 2.4 Specific therapies for heart failure	≥ 1 ATC code for sacubitril–valsartan OR Combination of ATC codes for (ACE inhibitor or ARB) and β-blocker and MRA (medication table in Appendix 4)
Definition 2.5	Definition 2.1 OR Definition 2.3 OR Definition 2.4
Definition 3.1	Definition 2.1 with furosemide and without EMR billings table, as follows: ≥ 1 ICD-9 codes in EMR health condition table or EMR encounter diagnosis table (Appendix 5) AND ≥ 1 ATC code for any ACE inhibitor or any ARB or β-blocker or MRA or hydralazine or furosemide; as listed in the medication table in Appendix 4 OR Definition 2.3 without EMR billings table: ≥ 2 ICD-9 codes (Appendix 5) in EMR health condition table or EMR encounter diagnosis table, separated by ≥ 30 d OR Definition 2.4
Definition 3.2	Definition 2.1 with furosemide, as follows: ≥ 1 ICD-9 codes in EMR health condition table or EMR encounter diagnosis table or EMR billings table (Appendix 5) AND ≥ 1 ATC code for any ACE inhibitor or any ARB or β-blocker or MRA or hydralazine or furosemide; as listed in the medication table in Appendix 4 OR Definition 2.3 OR Definition 2.4
Definition 4.1 Low-threshold BNP	Definition 1.1 OR BNP > 50 or NT-proBNP > 125
Definition 4.2	Definition 1.2 OR BNP > 50 or NT-proBNP > 125
Definition 4.3	Definition 3.2 OR BNP > 50 or NT-proBNP > 125
Definition 5.1 High-threshold BNP	Definition 1.1 OR BNP > 400 or NT-proBNP > 450 for patients aged < 50 yr, > 900 for patients aged 50–75 yr, >1800 for patients aged > 75 yr
Definition 5.2	Definition 1.2 OR BNP > 400 or NT-proBNP > 450 for patients aged < 50 yr, > 900 for patients aged 50–75 yr, >1800 for patients aged > 75 yr
Definition 5.3	Definition 3.2 OR BNP > 400 or NT-proBNP > 450 for patients aged < 50 yr, > 900 for patients aged 50–75 yr, >1800 for patients aged > 75 yr

Note: ACE = angiotensin-converting-enzyme, ARB = angiotensin II receptor blocker, ATC = Anatomical Therapeutic Chemical, BNP = brain natriuretic peptide, EMR = electronic medical record, ICD-9 = International Classification of Diseases, Ninth Revision, MAR-net = Maritime Family Practice Research Network, MRA = mineralocorticoid receptor antagonists; NT-proBNP = N-terminal pro brain natriuretic peptide.