Fifty years ago parents and guardians of 900 Aberdeen primary pupils filled in a survey about their children's respiratory health.
University of Aberdeen researchers could not have predicted it at the time but their simple survey was to go on to become an important barometer of asthma in the UK and parts of Europe.
Five decades on and a questionnaire, which includes the identical questions used back in 1964, is about to be sent home with pupils attending exactly the same Aberdeen City primary schools as before.
It is highly likely that some of the children involved in this latest survey will be third generation of their family to take part in these surveys.
Dr Steve Turner, Senior Clinical Lecturer in Child Health at the University of Aberdeen and Honorary Consultant Paediatrician with NHS Grampian, explained the background to the study which he now heads: "Fifty years ago the initial survey was sent out to Aberdeen City schools with the principal aim of examining educational outcomes in primary school children.
"Questions on asthma, eczema and hayfever were included in the questionnaire which went to pupils aged primary five to primary seven. Such conditions were thought to be relevant to education because in those days children with bad asthma were sent to special schools."
That first survey was completed in May 1964 and since then the Aberdeen School Asthma Study – as it has become known – has subsequently been repeated in the same schools in 1989 and every five years after that.
"These surveys have given us incredibly helpful insights to asthma prevalence in Aberdeen over the years. And if you plot that prevalence over time against other studies, asthma frequency elsewhere shadows that in Aberdeen with uncanny precision," said Dr Turner.
"Over the years our results have shown that eczema and hayfever rates have remained high despite asthma rates dropping. We know that not all children with asthma have allergies and not all children with allergies have asthma. Our results are further evidence that asthma may not be caused by allergy. Asthma affects just the lungs so it makes sense that the underlying cause is a problem with the lungs and not allergy which is a problem with the immune system."
Researchers hope parents and guardians will take the few minutes required to fill in the surveys when they arrive home in pupils' school bags.
"Fifty years ago the team had a 90% response rate – but in those days they were able to go knocking on people's doors and try to persuade people to fill the forms in!," added Dr Turner.
"We can't do that nowadays of course but we do hope that parents will complete our forms because the information that they provide will be hugely informative. Forms can be filled in on paper versions and posted back to us free of charge or filled in on line. It should take less than 5 minutes to fill in the questionnaire.
"We hope that the survey of 2014 survey will demonstrate a drop - possibly a big drop - in asthma prevalence. The information we gather over the next few weeks will be pieced together with all the data collected since 1964 to try to find out why has asthma prevalence has changed over the years."
Chest Heart and Stroke Scotland (CHSS) have supported the Aberdeen School Asthma Survey with funding of nearly £60,000.
CHSS Chief Executive David Clark said: "Chest Heart & Stroke Scotland has supported this important research for many years. It has provided very valuable insights into the rise and recent fall in asthma prevalence, not just in Aberdeen but throughout Scotland, and contributed significantly to the improvements in treatment which have helped bring this about. Asthma is still a condition which can cause a great deal of distress, and we would urge everyone contacted by the team to complete the questionnaire so that the work can continue."