Anyone familiar with my research program will know that I'm always looking for new and innovative ways to capture data in clinic that is normally so resource-intensive it is usually reserved for labs or highly specific and well-funded applications. Sometimes this is through simplified patient self-report measures, sometimes through simplified clinical tests, or sometimes through less expensive alternatives to high-precisions instruments. An example of the latter is the new FitBit Wireless Activity tracker available from www.fitbit.com. This thing is loaded with all sorts of technical goodness, including an accelerometer and an altimeter, which means it can not only count the steps you take in a day (a la a pedometer), but also how fast you were moving, and whether or not you were moving up or down hill (or up or down stairs as it were). It then corrects your calorie usage through knowledge of these other parameters, making it far superior to a standard pedometer. It also has a 'sleep tracking' mode, which has you move the little USB-drive-sized device from your pocket (where it normally clips happily and unobtrusively throughout the day) to a specially-designed comfortable wristband for sleeping. While on your wrist, it basically tracks how restless you were throughout the night by monitoring the amount your arms have flailed about. It will then send all of this information wirelessly through a USB-connected base station/charger any time you're close to your computer, and you can track your calorie expenditure and sleep habit either online or through handy smartphone apps. So far pretty cool, right?
Pictures are taken directly from the FitBit.com website.
What drew me to this is that, if we believe the cognitive-behavioural model of chronic pain development, the crux of that model is that catastrophizing and fear of movement lead to disuse and deconditioning, and hence chronic pain and disability. People have tried in the past to monitor change in activity using a variety of approaches, many of them through use of pedometers, accelerometers, GPS, personal digital assistants, one-shot fitness indices (body fat, strength) or plain old diaries. So far the results are mixed, with a paper from Dr. Vlaeyen himself suggesting that physical acitivity level doesn't change appreciably over the course of chronic pain development. Colleagues of mine have tried more advanced approaches (unpublished) through use of a wearable vest that incorporates motion sensors, heart rate sensors, and other such technologies that cost several thousand dollars. This is the 'resource-intensive' bit I was talking about in the opening sentence.
Enter the FitBit. While it won't provide heart rate data, it will give total motion data, including speed of movement and change in altitude, and an indicator of 'restfulness' while asleep. All for $99. So I had to give it a go to determine whether it would be something I could distribute in a prospective cohort study to evaluate overall movement from say weeks 1 and 2 to weeks 51 and 52 after an acute injury. Here's my experience:
Like any movement sensor, it's possible to 'game' the device by sitting on your couch and shaking it around, but who are you really cheating there? Setting it up is not hard, but it does require the download of a driver which some people who are a bit more computer-phobic might not like (I'm thinking about my standard subject here). As a researcher, I love the fact that I can pull the data from the website any time I want by logging into the FitBit 'Dashboard' and seeing total calories spent and monitoring sleep effectiveness. This also gives me real-time information about compliance, which is a HUGE bonus. Here's what a fairly typical, perhaps slightly above-average day looked like for me:
Actually, that's probably considerably above average, considering I generally sit in front of a computer most of the day. The dashboard also gives a sort of summary activity level:
Which would be difficult to analyze as is but could be tailored I suspect. And finally, a sleep pattern:
This could come in particularly handy if we believe, as I do, that disturbed sleep is a key indicator of the development of chronic pain.
As far as a clinical/research device, it definitely holds potential. Some of the possible challenges that would need to be overcome are really just logistic - I occasionally found myself forgetting to put the tracker into the wrist band before bed, then forgetting to take it out and clip it back onto my pajamas when I awoke, and then forgetting to take it off my pajamas and put it onto my pants when I got dressed. I suspect subjects who aren't as fully engaged as I am would probably forget this even more often. Similarly, I occasionally forgot to put it into sleep mode before I went to bed, or to take it out of sleep mode when I got up. This is in no way a criticism of the device, rather when looking at this is as a potential research tool, one needs to consider anything that could bias your results. That said, it is far superior to either a pedometer or GPS, and is smaller than some other motion sensors I've seen in the past, so definitely has a lot going for it. The cost is another big plus. For $5000 I could get 50 of these on a nice prospective cohort and track movement (calories would probably be the key indicator here) over time. As a clinical tool, these also hold promise for tracking change in activity over time, especially for people with chronic disabilities.
Now I have to mention one more thing, and this is both a pro and a con. The device is small and unobtrusive which is great, but as it turns out is also easy to lose. As I did. After only 2 weeks. D'oh! Now I have to say that the customer service at FitBit are AMAZING. They have a discounted replacement program, and even offered to replace mine for free (the first time), as long as I promised not to be such a moron again. Well, they didn't say that exactly, but I read between the lines. Again, AH-MAZING. However, this does raise some concern as far as using this as a research or clinical tool - it could become pricey if they keep getting lost. I will from now on be including a label with my phone number on any ones that I get. But I would also like to see something like maybe a user-configurable 'alert' system, in which the device can be set to start beeping after some specified period of complete immobility, say 12 hours.
All in all, I love the fact that we are seeing high tech gagets at consumer-accessible prices. Now, evaluation of patient activity level doesn't have to be confined to the clinic. I continue to be excited by the next advancement in health technology. Can't wait to see what else comes down the pipes.