Using data linkage to improve national monitoring of stroke and coronary heart disease
The article was originally posted on LinkedIn by Miriam Lum on, Head of the Cardiovascular, Diabetes & Kidney Unit.
Today my team have released two exciting new reports that use linked data to improve our understanding of stroke and coronary heart disease.
It is with much anticipation that we have used the National Integrated Health Services Information Analysis Asset (NIHSI AA) to shed new light on the burden of cardiovascular disease in Australia and improve AIHW’s monitoring work in this space.
NIHSI AA links deidentified data from hospital admissions, emergency department presentations, residential aged care, the National Death Index, and services provided under the Medicare Benefits Schedule and prescriptions supplied under the Pharmaceutical Benefits Scheme and Repatriation Pharmaceutical Benefits Scheme.
Without linked data, there is no direct way to count the number of new stroke or acute coronary syndrome (ACS) events at the national level. (Note that ACS includes both heart attacks and unstable angina). Until now, AIHW has used algorithms based on unlinked data to report these events. However, the algorithms cannot differentiate between recurrent and new events.
The first report, Estimating the incidence of stroke and acute coronary syndrome using the National Integrated Health Services Information Analysis Asset uses linked hospitalisation and deaths data from 2011 to 2018 to provide the most accurate estimate of the incidence of stroke and ACS events in Australia than previously available. This report has been able to differentiate between new and recurring events, and multiple hospitalisations for the same person.
Key findings include:
- In 2018, almost 29,000 Australians had a stroke for the first time and 40,200 had an ACS event—equating to 79 and 110 events daily, respectively.
- Between 2011 and 2018, the rate of new and repeat strokes estimated from the linked data remained fairly stable, between 150 and 153 per 100,000 population.
- Males had more strokes than females (after adjusting for age differences).
- Stroke increased with age, with the rate of the 85 and over age group (1,700 per 100,000 population) more than 5 times the rate of the 65–74 age group (308 per 100,000 population).
- The rate of people with new and repeat ACS estimated from the linked data fell from 472 to 337 per 100,000 population between 2011 and 2018.
Monitoring the incidence of stroke and ACS is crucial for assessing the health and economic burden of these conditions on Australians, health service planning and evaluating progress in prevention and management.
The second report, Medication use for secondary prevention after coronary heart disease hospitalisations: patient pathways using linked data, also uses linked data from the NIHSI AA to reveal insights into patient pathways following coronary heart disease hospitalisations.
The study examined 67,800 people who had been admitted to hospital with coronary heart disease (CHD) between 1 July 2016 and 30 June 2017. About half (35,200) of these people had ACS, which is the most severe form of CHD.
Key findings include:
- 3 in 5 (61%) people with ACS were dispensed 3 or more of Guideline recommended cardiovascular medicines within 40 days of leaving hospital.
- Women and people who underwent coronary artery bypass grafts were less likely to be dispensed the recommended medicines within this time frame.
- People who had been dispensed the medicines in the year before going to hospital were significantly more likely to be dispensed medicines after being discharged from hospital and to be still taking them 1 year later.
Today’s release provides a better understanding of some of the factors that affect medication use by CHD patients discharged from hospital. However, further work is required to identify why some population subgroups were less likely to initiate, or continue to access, preventive medications after hospitalisation for ACS.
The use of linked data in today’s reports highlights its importance in providing a more complete picture of how people with cardiovascular disease use and interact with the health system. We are working closely with our expert advisory group on further analysis examining the relationship between medication adherence and the risk of subsequent CVD hospitalisations and death. Watch this space!