Drug therapy and counselling to prevent heart attacks and strokes in eligible persons (Indicator 18)
Updated
The indicator describes the following: Proportion of eligible people (defined as individuals with existing cardiovascular disease or who have a 10-year cardiovascular risk of 30 per cent or higher) receiving drug therapy and counselling to prevent heart attacks and strokes.
The indicator describes the following: Proportion of eligible people receiving drug therapy and counselling to prevent heart attacks and strokes. Eligible people are defined as individuals with existing cardiovascular disease or who have a 10-year cardiovascular risk of 30 per cent or higher.
This indicator is part of Target (8): At least 50 per cent of eligible people receive drug therapy and counselling to prevent heart attacks and strokes.
A combination of age, gender, smoking status, blood pressure and total cholesterol will identify a group of eligible individuals with a 10-year cardiovascular risk of 30 per cent or higher based on the NORRISK 2 score. The group of eligible persons also includes all individuals who report that they already have or have suffered from a heart attack or stroke.
We report the proportion of eligible persons reporting use of medication that lower blood glucose, cholesterol and blood pressure.
Results
The proportion reporting use of blood glucose-lowering, cholesterol-lowering and/or blood pressure-lowering medications among 45-74 year-olds with known angina, heart attack or stroke, or at high risk of cardiovascular disease, increased from 66 per cent in 2006-2007 to 83 per cent in 2015-2016. This is shown by data from the Tromsø Study.
The group of eligible persons was mainly comprised of people who reported having known heart attack or stroke (Figure 1). Reported use of medication to reduce the blood’s ability to form clot is not included in the calculation. This means that the proportion receiving drug therapy to prevent heart attacks and strokes may be higher than shown in Figure 1.
Figures from national analyses in the Norwegian Cardiovascular Disease Registry and the Norwegian Prescription Database show that around 90 per cent of the patients who were admitted with heart attacks and/or strokes in 2012-2013 collected prescriptions for medications that prevent blood clots. See paper from the Norwegian Cardiovascular Disease Registry (in Norwegian).
Table accompanying Figure 1
| 2007-08 | 2015-16 |
Total eligible persons | 65.7 | 83.2 |
Of which persons with self-reported angina, heart attack or stroke constitute the following percentage points | 59.2 | 77.3 |
Of which persons with NORRISK 2 ≥ 30 per cent without self-reported angina, heart attack or stroke constitute the following percentage points | 6.5 | 5.9 |
Table 1. Proportion reporting use of blood glucose-lowering, cholesterol-lowering and/or blood pressure-lowering medications among eligible persons in Tromsø, in per cent. Eligible persons are defined as people aged 45-74 years with self-reported angina, heart attack or stroke, or who have a 10- year cardiovascular risk of 30 per cent or higher, as estimated by the NORRISK 2 score. Source: The Tromsø Study.
Data sources
The data source for this indicator is the Tromsø Study.
A description and definitions follow below.
Data source: Tromsø Study
Description
The Tromsø Study began in 1974 and consists of repeated health surveys on Tromsø municipality’s population. Tromsø6 (2007-2008) included almost 13 000 adults aged 30-87 years and had an attendance rate of 63 per cent. Tromsø7 (2015-2016) included more than 21 000 adults aged 40 years and older and had an attendance rate of 65 per cent.
Effect measure
Proportion among eligible persons who in questionnaires report current use of blood glucose-lowering, cholesterol-lowering and/or blood pressure-lowering medications. Eligible persons are here defined as individuals aged 45-74 years who reported having cardiovascular disease (angina pectoris, heart attack or stroke), and/or persons with at least a 30 per cent risk of having a heart attack or stroke within the next 10 years, as estimated by the NORRISK 2 score.
Blood glucose-lowering, cholesterol-lowering and/or blood pressuring-lowering medications include one or more of the following:
- Blood glucose-lowering medications including insulin
- Blood pressure-lowering (antihypertensive) medications
- Cholesterol-lowering medications
The risk of developing cardiovascular disease within the next 10 years was estimated using the NORRISK 2 score. The risk score is a combination of age, gender, smoking status, blood pressure, blood pressure-lowering medications, total cholesterol, HDL cholesterol and having close relatives who had a heart attack at an early age. The score indicates a person’s risk of having a heart attack or stroke within the next 10 years. The risk score is based on Norwegian health surveys, hospital admissions and causes of death.
NORRISK 2 references
- Research article on NORRISK 2: Selmer R et al. NORRISK 2: A Norwegian risk model for acute cerebral stroke and myocardial infarction. Eur J Prev Cardiol 2017;24(7):773-782
- NORRISK 2 risk calculator
- NORRISK 2 figure
- National clinical guideline for the prevention of cardiovascular disease (in Norwegian)
Interpretation and sources of error
In the Tromsø Study we do not have data on the reported use of medications that reduce the blood’s ability to form clots. This means that the proportion who receive drug therapy to prevent heart attacks and strokes may be higher than the numbers in Figure 1.
The proportion of individuals attending health surveys has gradually declined over time. No assessment has been made of whether changes in attendance rates have any impact on the comparability of numbers over time.
Global indicator definition
World Health Organization (WHO)’s definition of the indicator
Indicator 18. Proportion of eligible persons (defined as aged 40 years and older with a 10-year cardiovascular risk ≥ 30 per cent, including those with existing cardiovascular disease) receiving drug therapy and counselling (including blood glucose control) to prevent heart attacks and strokes.
National adaptation
We have calculated the risk of cardiovascular disease using the NORRISK 2 score, which is based on the Norwegian context. We did not use WHO’s risk score (WHO/International Society of Hypertension risk prediction chart). NORRISK 2 and WHO’s risk score are based on many of the same risk factors. The scores differ in some areas; NORRISK 2 additionally includes family history of heart attacks and HDL cholesterol but does not include diabetes in the risk score.
We have provided numbers on the proportion receiving drug therapy to prevent cardiovascular disease. We do not have data on the proportion receiving preventive counselling.
The WHO has defined preventive drug therapy as including medications that lower blood glucose, cholesterol and blood pressure, as well as medications that reduce the blood’s ability to form clot, e.g., acetylsalicylic acid. The Tromsø Study does not provide data on the reported use of medications that reduce the blood’s ability to form clots. We have therefore supplemented with data from the Norwegian Cardiovascular Disease Registry and the Norwegian Prescription Database on the use of clot-preventive medications in patients who have been admitted with heart attack and/or stroke.