New Study Finds No Link Between Rainfall and Joint Pain – What Do You Think?
Can the weather affect rheumatoid arthritis (RA) symptoms? It’s a question that I’ve seen come up over and over again in this community. Personally, I’ve never noticed much of a connection between the weather and my joints. Sometimes my joints seem to hurt a bit more if I’m really cold and I certainly feel more swollen when it’s really hot, but I’ve never been able to predict a rainstorm or anything like that.
RA: A unique struggle for everyone
But if there’s one thing I’ve really learned about RA in almost a decade since my diagnosis it’s that RA affects everyone uniquely. And there are many others living with RA – who I know and trust – who have made a connection between symptoms and the weather. Take my friends Leslie, Wren, and Tamara. They’ve all been living with RA for many years and have been able to establish a connection between their own pain and the weather.
So what does science have to say about this question? Previous studies have resulted in mixed conclusions. These studies also faced issues like small sample sizes (i.e. not enough data), problems of recall (i.e. patients may have had trouble remembering details from a while ago accurately), and the potential for confirmation bias (i.e. if you already personally believe the weather affects your RA you’re much more likely to answer survey questions in a way that confirms that belief).
What exactly is the deal between RA and weather?
To address these limitations, a research team led by Anupam B. Jena, Associate Professor at Harvard Medical School, took a different approach. Instead of surveying patients directly they attempted to address the question by analyzing data from millions of outpatient visits. Their hypothesis was that if a true relation exists between rainfall and joint pain, patients might be more likely to seek care from their doctors for those conditions during rainy periods. Or, alternatively, patients might be more likely to mention joint pain when seeing their doctors during a previously scheduled appointment that happens to occur during a rainy period.
The researchers decided to focus on outpatient visits with general internists or primary care physicians, rather than specialists like rheumatologists. They hypothesized that these doctors most frequently treat patients with acute joint pain. They also assumed that general internists are more likely to be able to see patients at short notice than specialists.
Using a Medicare database, researchers looked at records from 1,552,842 adults from the period of 2008 to 2012. They looked to see whether outpatient visits included a diagnosis code for a condition reflecting joint pain. Then they used data from the Global Historical Climatology Network Daily database to determine daily precipitation measurements matching the geographic zip code of the patient’s residence. To explore potential changes in barometric pressure, researchers identified the week that the outpatient visit occurred and determined how many days in that week the weather station had recorded precipitation.
Of all of the outpatient visits that included joint pain, the results showed that only 18% occurred on rainy days. This means that the researchers were not able to identify a statistically significant relationship between visits related to joint pain and rainfall – either on the day of the appointment or during the preceding week. Ultimately, the rate of joint pain reported during weeks with seven rainy days turned out to be similar to weeks with zero rainy days.
But what about what patients actually experience?
While the results of the study seem to debunk the commonly held belief that changing weather conditions may lead to an increase in joint pain, this new study does have some potential limitations of its own. For one thing, since this study relied on administrative data of outpatient visits, it could not detect patients with increased pain who chose to self-manage instead of visiting their doctor. Additionally, since the data came from a Medicare database, it included only patients who were older than 65. Lastly, this study focused specifically on rainfall, rather than other weather measurements such as humidity, barometric pressure, or temperature.
Nevertheless, this was a large scientific study that found no relation between rainfall and outpatient visits for joint pain. What do you think?