Health Inequities in Manitoba: Is the Socioeconomic Gap

Health Inequities in Manitoba: Is the Socioeconomic Gap in Health Widening or Narrowing Over Time?
Chapter 8: Pharmaceutical Use
Post-Acute Myocardial Infarction (AMI) Care: Beta-Blocker Prescribing
Definition
Beta–blockers, properly known as beta–adrenergic blocking drugs, have been shown to lower the risk
of subsequent heart attacks after patients have suffered an AMI.
Definition: the proportion of patients aged 20 and older hospitalized for Acute Myocardial Infarction
(ICD–9 CM code 410; ICD–10 code I21) who filled at least one prescription for a beta–blocker (ATC
C07AA, C07AB) within four months of their AMI.
Patients with a diagnosis of asthma, COPD, or peripheral vascular disease were excluded because beta–
blockers are contra–indicated for those patients. Patients with a hospitalization for AMI in the preceding
three years were also excluded to remove those experiencing multiple heart attacks in a relatively short
period.
Exclusions for contra–indications:
• asthma, ICD–9–CM code 493; ICD–10–CA code J45
• chronic obstructive pulmonary disease, ICD–9–CM codes 491 and 492; ICD–10–CA codes J41–
J44
• peripheral vascular disease, ICD–9–CM codes 443 and 459; ICD–10–CA codes I73, I79.2, I87
NOTE: Up until the year 2005, northern First Nations community pharmaceutical data may be missing
due to lack of prescription data being entered into the DPIN system. However, as of 2005 to the present,
prescriptions for First Nations communities are dispensed through a private pharmaceutical company
that reports all prescriptions through DPIN.
Time Periods Percentage of patients post-AMI with beta-blocker prescription
T1: 1996/97-1998/99 65.28
T2: 1999/00-2001/02 75.92
T3: 2002/03-2004/05 80.58
T4: 2005/06-2007/08 81.28
Key Findings: Post-Acute Myocardial Infarction (AMI) Care: Beta-Blocker Prescribing
Manitoba overall rates:
• From the first time period T1 (1996/97-1998/99) to the last time period T4 (2005/06-2007/08), the
percentage of patients with an AMI who filled at least one prescription for a beta-blocker within four
months of their AMI increased from 65.3% to 81.3% provincially.
Manitoba Centre for Health Policy 165