Smartphone study on weather and pain reveals early data
A study looking at how the weather affects chronic pain has released some early, surprising results.
People across three UK cities reported less time in severe pain as the weather warmed up from February to April - but pain then increased again in June.
Researchers are collecting the data via a smartphone app and hope to shed scientific light on the idea that we can "feel the weather in our bones".
They presented a project update at the British Science Festival in Swansea.
Eventually, the "Cloudy with a Chance of Pain" project will match up individual responses with local weather patterns, based on GPS data from the participants' phones.
Because the app also asks people about their mood, this more detailed analysis will also reveal whether the weather has an affect beyond simply making people happier.
For the moment, however, even a preliminary month-by-month overview of the combined pain data from Leeds, Norwich and London - alongside the general weather pattern for those cities - shows that there is more to this much-discussed interaction than we might expect.
"This is just a quick snapshot," said project lead Will Dixon, a rheumatologist and professor of digital epidemiology at the University of Manchester.
"But one interesting thing it does is [challenge] that really common belief... that joints get worse if it's cold. Actually, the pain got worse [again] from April to June, and that was the one time when the temperature really went up.
"So it doesn't fit with that really common hypothesis."
Prof Dixon and his colleagues are still seeking more participants, and will be collecting data until April 2017.
So far more than 9,000 people with chronic pain have downloaded the app and joined the experiment.
"Of those, about one in six people have entered their symptoms almost every day for six months," Prof Dixon told the BBC. "We can really make the most of their data."
An additional element of the project allows interested observers to explore the data so far, on the project website.
This is partly about getting people interested - but Prof Dixon said it will also help speed up the research.
"Anyone can interact with the data and try to spot relationships," he said - for example, between temperature and mood, or air pressure and pain levels.
"We can kind of crowd-source everyone's hypotheses about our data. That will allow us to circle in on the right answer for the analysis, more quickly than we would otherwise do."
He and the team are confident that their study will unravel whatever the relationship might be between the weather and pain. The app, Prof Dixon explained, offers an unusually regular insight into people's symptoms.
"Many studies just ask people about their pain on one day - so that doesn't really allow you to measure the change in symptoms with weather patterns."
This level of detail, he added, will probably reveal a complex pattern rather than a simple correlation.
"I think there's likely to be subgroups of patients with different relationships."
Follow Jonathan on Twitter