Health New Zealand | Te Whatu Ora provides a Health Information Standards Organisation (HISO) based Cardiovascular Disease Risk Assessment (CVDRA) service for New Zealand healthcare providers.

The CVDRA service, based on algorithms specific to the New Zealand population, helps show the risk of a person between ages 30 and 74 having a serious cardiovascular event in the next five years.

Accessible data

The CVDRA API is free to use and can be integrated with an appropriate practice management system (PMS) and/or a user interface (UI) for end-users.

The CVDRA API calculates the cardiovascular risk based on parameters which both specify the type of algorithm to use and the values for calculation.

The variables used to calculate cardiovascular risk include:

  • age
  • sex
  • National Health Index (NHI) number
  • ethnicity
  • New Zealand Deprivation Index (NZDep) score
  • height, weight, smoking status, diabetes, personal health history, family health history, and other clinical measures directly related to cardiovascular disease risk.

Once complete, the CVDRA API returns a five-year risk value, along with information based on this risk, for example heart-age and risk trajectories.

Who can use this API

The API is intended for integration with:

It can then be used by primary health organisations (PHOs), general practitioners (GPs), nurses, health service providers and the public.

Use cases 

The following are a few scenarios that the API might be used for.

  • Assess the CVD risk of a patient.
  • Discuss care planning and risk management with a patient.
  • Enable patients to calculate and understand their CVD risk.
  • Generate and print a report of your cardiovascular risk.
  • Create an application for the public to estimate their risk of heart attack and stroke.

Onboarding and implementation

If you're a health provider and are interested to access the Service or want to know more about the technical aspects of it, please visit Consumer onboarding - Health New Zealand.

API types

REST API 

API use clarification

The CVDRA API implements a NZ specific set of CVD Risk equations, which the CVDRA HISO standard provides full specification details for. Use clarification can be found with the HISO standard and will be regularly updated as queries arise. 

Albumin to creatinine ratio (ACR)

Albumin to creatinine ratio (ACR)

1. When to use the ACR value in the CVDRA.

Only use the ACR for diabetic patients.

However, if the ACR ≥ 30, refer to 6.

2. When to collect urinary albumin to creatinine ratio (ACR) collection (urinary microalbumin) for people with diagnosed diabetes.

The 2018 CVD consensus statement recommends collecting a urinary albumin to creatinine ratio (ACR), at least annually.

 

3. Is ACR used in the calculation for a diabetic patient?

Yes, however, if the ACR ≥ 30, refer to 5.

4. Is ACR used in the calculation for a non-diabetic patient?

Do not supply the ACR for non-diabetic.  However, if the non-diabetic equation is supplied with an ACR value it will be ignored, except when it is ≥30.

Please refer to 5. 

5. If the ACR ≥ 30

If a person has an ACR consistently above 30mg/mmol, they are diagnosed as having overt diabetic nephropathy or macroalbuminuria.

At this level, they will have the CVD risk of someone with prior CVD and are excluded from having a risk score calculated using primary prevention equations.

Excluded for a diabetic or non-diabetic patient who has an ACR ≥30.

If supplied, the API will return a clinically high flag indicating the equation should not be used and the patient should be considered to be in the high risk category. 

6. For diabetic patients who return ACR results of ≥30

Exclude/ignore. 

Do not use the ACR for a diabetic or non-diabetic patient who has an ACR ≥30.  However, if the ACR ≥30 is supplied the API will return a clinically high flag, indicating the equation should not be used and the patient should be considered to be in the high-risk category.

7. For non-diabetic patients who return ACR results of ≥30

Do not use the ACR for a diabetic or non-diabetic patient who has an ACR ≥30.

Please refer to 5.

Data age

Data age

1. Data age for each health data point to be valid for CVDRA calculation.

Preferred data age is 0-3 months old, however 0-1 year old is acceptable.

Blood pressure

Blood pressure

1. Blood pressure value for CVDRA calculation

Case examples include: 

  • Consumer known for having elevated blood pressure over a few years but not on medication produces a lower measurement on a day CVDRA is done. Should the clinician use the persons average or immediate measurement for CVDRA?  
  • If the blood pressure has been known to be high over a few years then this should be investigated further, perhaps with ambulatory blood pressure recordings over 24hr or recordings taken by the patient on a home blood pressure machine at home at different times of the day over the course of 1-2 weeks.  
  • Consumer has been on blood pressure lowering medication for a while. Can the immediate blood pressure reading be used for CVDRA?  

The use of a CVDRA is to manage risk factors. If the blood pressure is normal on treatment then that reading should be the input. Patients should not be asked to stop any treatment prior to a CVDRA.

2. Blood pressure measurement is three months old and a new one cannot be obtained at the time of the consultation. Can the last (old) measurement be used?  

Preferred to have health data 0-3 months old, however 0-1 year old is acceptable.

Technical

The CVDRA service is currently operated on the Microsoft Azure cloud platform. API implementation details can be found on the Swagger UI website.

Systole cardiovascular risk calculator API — Swagger UI