First SARS-CoV-2 study in a representative random sample in Austria

The Austrian Ministry of Science launched this study to determine the spread of SARS-CoV-2 including the “dark figure” in Austria. It is the first study in continental Europe based upon nationwide PCR testing in a representative random sample. Self-selection into the sample was not allowed, and various strategies have been applied to limit sampling bias and non-response which led to a substantially higher participation rate than in comparable studies.

Key results

PCR tests (cobas® SARS-CoV-2) were carried out in the period April 1–6, 2020. 1,544 cases have been included in the final analysis.

  • 6 respondents have been positively tested.
  • The proportion of positively tested in the final weighted sample is 0.33%. This proportion represents about 28,500 individuals among the Austrian population, excluding those currently in hospital.
  • Applying a 95% confidence interval for the proportion of positively tested results in a range between 0.12 and 0.77% or between 10,200 and 67,400 individuals in absolute terms.

Follow-up telephone survey

During collection of PCRsamples, subjects were asked for their consent to participate in a follow-up telephone survey. At 97%, agreement to participate was very high. Questions were asked mainly about health status and social contacts before and during "lock-down". Detailed results can be downloaded here (PDF, German).

Project consortium

Commissioned by: Republic of Austria, represented by the Federal Ministry of Education, Science and Research (BMBWF).

Project consortium:

  • SORA Institute for Social Research and Consulting (project lead, co-ordination, sample, data analysis), closely co-ordinated with:
  • Institut für statistische Analysen Jaksch & Partner GmbH (hotline, sample management, telephone interviews)
  • Medical University of Vienna(evaluation of PCR tests)
  • Complexity Science Hub Vienna CSH (statistical-medical expertise)

Directly commissioned by the BMBWF:

  • Austrian Red Cross and its national associations (carrying out PCR tests throughout Austria)