GVDN Background

Data Dashboard

Background rates
  • Health conditions occur normally in the population with people becoming ill every day and seeking treatment. To understand if a vaccine (or any other medicine for that matter) increases the rates of people developing a medical problem we must first understand what is normal, when there is no vaccine being used (background rates).

  • Next, we need to observe if we are seeing more cases than we might normally expect (observed over expected rates). If we are then we might have a safety signal that needs investigating more thoroughly. Seeing more cases of a condition than we might normally expect could me due to many reasons, such as circulating viruses, weather, social changes.

  • To determine if a vaccine is causing some of the cases, we need studies that compare the risk of a condition in vaccinated people compared with unvaccinated people (association studies).

Background rates of AESIs in New Zealand 2008–2019 project

As with other countries, New Zealand did not have the baseline data required to form the basis of robust vaccine safety monitoring prior to the COVID-19 pandemic and introduction of COVID-19 vaccines. The outcomes of the Background rates of AESIs in New Zealand 2008–2019 project, the data for which are available in the data dashboard below, helped prepare New Zealand for local assessment of COVID-19 vaccine safety by establishing baseline rates for 20 adverse events of special interest (AESIs) extracted from the Brighton Collaboration SPEAC (Safety Platform for Emergency Vaccines) project prioritised list, and myocarditis, pericarditis, multisystem inflammatory syndrome, a range of haematological conditions potentially associated with the newly identified thrombosis with thrombocytopenia syndrome (TTS), herpes zoster (shingles), narcolepsy, and sudden death for the New Zealand population overall and key subgroups from 2008–2019. These background rates may be used as a first step to contextualise data from prospective monitoring studies, spontaneous reports from the Centre for Adverse Reaction Monitoring (CARM) and other databases, and case reports, and thereby form a basis for identifying potential COVID-19 vaccine safety signals. With the baseline established, signals may be verified through the conduction of observed over expected analysis with the same population cohort.

Brief guide for using the dashboard

Data can be viewed in graph or table format by AESI and patient type as combined data, or by sex, age group, prioritised ethnicity, Index of Multiple Deprivation (IMD) without health, NZ Deprivation Index, and geographic region. Information describing the site, data source(s), active population, and patient type has been provided by each site and is available in the third tab.

 Clicking on the question icon beside each data set provides additional information related to the variables in that set. 

In the graph view, tab one, clicking on the camera icon  will download a picture (PNG) file of the plot. It is possible to zoom in and out of the plot by clicking on the plus and minus icons , clicking on the house icon  will reset the plot axes. While in the graph view, hovering the mouse over a data point will show the closest data numerically

Data provided in the table view, tab two, can be downloaded as an Excel spreadsheet in the Download tab.

In tab three, information describing the site, data source(s), active population, and patient type has been provided by each site.

 Options in tab four allow the data plot to be downloaded as either a SVG or PNG file, and the dataset to be downloaded as an Excel file.

 The data dashboard will time-out and the screen will become grey if the dashboard is left idle for too long. Refreshing the webpage will activate the dashboard again, previous data selections will need to be re-entered.