Closing the Gap on Aboriginal Cardiovascular Health disparities- Using Big Data to understand the patient health journey

Summary Cardiovascular (CV) disease is the largest contributor to the health gap between Indigenous and non-Indigenous Australians. This research will inform CV risk management pathways and identify how CV disease is managed across the primary and tertiary care continuum for Indigenous and non-Indigenous Australians.

Project Details

Background

Cardiovascular (CV) disease has an earlier age of onset in Indigenous Australians and is the largest contributor to the health gap between Indigenous and non-Indigenous Australians. Management gaps are especially common among Indigenous Australians with more than half not screened or treated for CV disease despite being at high risk

Aims

The overall hypothesis is that the CV health gap that exists between Indigenous and non-Indigenous Australians is due to Indigenous Australians being less likely to receive evidence-based-CV care despite being at higher risk of CV disease.

The specific aims of the study are to:

• Assess whether implementation of guideline-based-CV care differs for Indigenous versus
  non-Indigenous people
• Demonstrate CVD risk is significantly higher for Indigenous Australians such that existing CVD risk scores need to be re-calibrated to accurately predict CVD risk and events in the Indigenous Australian community
• Quantify the gap in CV health and economic outcomes between Indigenous and non-Indigenous Australians and the potential improvements that can be achieved with implementation of evidence-based-CV care.

Methods:

Study Population:

This is a retrospective cohort study. The study population is patients aged ≥ 18 years who provided biomedical data to MedicineInsight, the largest de-identified longitudinal primary health care data set in Australia. Indigenous status was recorded in the majority of patient records.

Data Source:

Clinical measures and absolute CV risk:

Participants’ baseline CV profile will be collected. Absolute CVD risk will be estimated using the Australian National Vascular Disease Prevention Alliance (NVDPA) risk assessment and risk management algorithm. Based on the algorithm, participants in the study will be categorized as being at low (< 10%), moderate (10–15%) or high (> 15%) absolute risk of a primary CVD event.

Evidence-based-CV care:

Evidence-based-CV care will be defined as prescription of blood pressure and cholesterol lowering medication in patients at > moderate risk of CVD.

Clinical events:

CV mortality will be identified by linking the MedicineInsight data-set to the Australian National Death Index. CV events (CV-related emergency department visits and hospital admissions) will be assessed in a sub-set of patients whose data has been linked to the Victorian Emergency Minimum Data-set and the Victorian Admitted Episodes Data-set. CV events will be identified using Australian refined diagnosis related groups and the International Classification of Disease diagnosis (version 10) codes for coronary heart disease, stroke, congestive heart failure and peripheral vascular disease.

Analysis:

A range of statistical analysis methods will be employed to determine whether evidence-based-CV care differs between Indigenous and non-Indigenous subjects, assess factors influencing the likelihood of receiving evidence-based-CV care and estimate the economic costs according to Australian refined diagnosis-related groups and hospital length of stay.

Outcomes

The findings of this research will inform CV risk management pathways and identify how CV disease is managed across the primary and tertiary care continuum.