Trial of badly needed read-at-a-glance color ‘barcode’ demonstrates it can help physicians see (and believe in) a patient’s pain.
The way people move is an excellent indicator of overall health, according to a multidisciplinary team of bioengineers and pain researchers at Switzerland’s cutting edge Laboratory of Movement Analysis and Measurement. Healthy, pain free people move around freely and easily. But when you’re in pain, you reduce your physical activity and move in different ways.
This simple observation led them to develop an original approach to evaluating chronic pain.
It was 10 years in the making, but a recently completed clinical trial confirms that these exercise physiologists and physicians have developed a clever, easy-to-use visual tool that doctors can adopt to assess their patients' pain levels quickly and objectively. More ‘warm’ color strips on the bar (orange & red) indicate times of higher activity levels corresponding with less pain; vs. ‘cooler’ blues indicating times of less activity. Red strips are prominent in pain free controls' barcodes. The results of the study with visuals were published online Feb 23 by the free-access journal PLoS One.(1)
"Movement is an objective indicator of pain. You move differently if you're in pain than you do if you're completely healthy," says corresponding author Dr. Anisoara Ionescu. "It's important for doctors to be able to evaluate that pain as precisely as possible."
Sensors Collect Data
Using data collected by sensors typically used by exercise physiologists, placed on different parts of the body, she explains, a doctor can quantify a patient's suffering, monitor progress, and adapt treatment appropriately.
The Problems with Depending on Patient Descriptions of Pain
Doctors typically try to assess the severity of chronic pain with an in-depth oral evaluation using a series of standard questionnaires. This method, however, gives a very static view of the patient's condition – how he or she felt on this day, at that time.
There are other problems with this approach as well. For example: Patients rate their pain on a scale from 1 to 10; but obviously we don't all feel a "5" in the same way. And some patients, such as children or the cognitively impaired, are simply unable to describe or communicate their pain at all.
Movement As An Indicator
The study monitored the physical activity of 15 healthy, pain-free subjects and 60 patients suffering from chronic pain. Sensors equipped with gyroscopes and accelerometers were attached to their chests and adjacent to their knees and ankles. The sensors recorded all the subjects' movements and periods of rest.
The result was that those who reported chronic pain moved differently than the healthy subjects. In particular, their active periods were punctuated by numerous brief rest intervals.
Using the new tool, the researchers were able to take data several days before, during and after treatment. Results from the different periods could be compared to obtain a precise assessment of how the treatment changed a patient's day-to-day activities.
"There is definitely a difference in behavior between healthy and chronically ill patients," says Eric Buchser, MD, a professor at the hospital in Morges, Switzerland, who is participating in the study. "But we're just starting to collect data. We still need to gather more and establish objective reference values between patients."
A 10-Year Collaboration to Refine the Pain Intensity Indicators
The Laboratory of Movement Analysis and Measurement has been working with the department of anesthesiology and pain management at the Morges Hospital, which Dr. Buchser heads, for 10 years.
"Our first studies focused on acute pain, and then we moved to the more persistent, nagging suffering known as chronic pain. However, we had very little objective information on the intensity of this kind of pain," Dr. Buchser explains.
• Walking, running, sitting, and lying down are all objective indicators. The scientists defined 18 different activity states: various combinations of activity type, intensity, duration, and how the activity is distributed over time.
• They used the temporal sequence of these different states to develop a visual tool, a kind of color 'barcode,' that would be easy for doctors to use on a daily basis. The structural complexity of the barcode was an indication of pain intensity.
• In a single glance, a doctor can see a patient's situation, his or her progress, and the effect of an applied treatment protocol.
Dr. Buchser has high hopes for the tool. "Eventually," he says, "the doctor could use this physical activity 'barcode' to help make a diagnosis, better target a therapy, evaluate its effectiveness, and adapt it appropriately over time."
1. See the free full text article PDF with tables and barcode examples - “Barcoding Human Physical Activity to Assess Chronic Pain Conditions”
Source: Based on Ecole Polytechnique Federale de Lausanne news release, Feb 23, 2012