A cross-sectional study has found that head and neck injuries related to cell phone use increased steadily over a recent 20-year period.

But that may not be meaningful in a relative risk way. The sample was just over 2,500 cases from 1998 through 2017. Media will trumpet 300 percent since 2007 but that doesn't make injuries common. It just means that as phones changed from phones to messagers to full-on portable televisions and computers people are able to walk and be distracted more.

Data are from the National Electronic Injury Surveillance System (NEISS) database, which collects data about emergency room visits from approximately 100 hospitals in the United States. As you might gather, with over 7,000 hospitals in America, 100 is a small group, and in other analyses it has been found that replacement of one hospital by another has changed results dramatically. This did not account for the differences in hospitals over time - it's reasonable to expect that injuries in Manhattan happen more than they do in the midwest. 

But relative risk versus absolute risk is an article for another time. We would expect injuries to go up given modern smartphone culture. When I had an office in Japan 15 years ago, I was amazed how many people were on their phones. Living for three years in Manhattan more recently meant I got to see the same thing in a major U.S. city, but Japanese people in 2004 did not walk into each other while noodling on their phones the way Americans in 2015 did. There were numerous times in Manhattan when someone bounced off of me because I was looking at a street sign or a traffic light crosswalk and they were walking while looking at their phone and ran into me. A few times they even got angry at me, as if the world is a sea of humanity and we must part for them. 

Here is the important chart.

It's not an epidemic despite the curve because the y-axis is in people-years, so from a real point of view we are talking about 8.99 new cases per 1 million person-years (2,709) estimated cases to 29.19 new cases per 1 million person-years. That's a change of only 20 in million person-years. And most of the injuries are going to be minor, people are not getting hit by cars now more due to cellphones than in the 1990s. Pedestrian hits have gone up recently, back to 1990 levels, but that is because people walk and bike more than they did 25 years ago, and cars are a lot bigger, which ate away gains made due to less drunk driving. Distracted people still get hit, but about as many as got hit because they were daydreaming in the past.

I have seen the way people hold their phones while they look and we shouldn't be surprised if there are more chronic ailments related to that in the future, the way carpal tunnel syndrome became a thing due to repetitive stress and keyboards in the 1990s, but it won't be an epidemic the way this makes it look.