JMIR Publications

ABSTRACT

Background:

Chronic pain is the leading cause of disability, affecting nearly half of the global population. One of the recommended treatments for chronic pain is physical activity, which can be measured in daily life by a pedometer. However, low adherence to the pedometer use could result in incorrect measurements. Due to the ubiquitous use of smartphones, we developed the “Pain-Note” app to collect step count and moving distance. With the use of the Pain-Note app, we obtained the real-world information with a smartphone built-in pedometer and assessed the relationship between daily life step count and pain.

Objective:

The aim of our research is (1) to evaluate the association between the daily step count and pain level using a pedometer developed on the iPhone smartphone among patients with chronic pain, and (2) determine if the association between the daily step count and pain levels is curvilinear.

Methods:

We conducted cross-sectional research with data collected from the “Pain-Note” app on step count and questionnaires, including the duration and intensity of pain, the widespread pain index (WPI) and symptom severity score (SS score), the insomnia severity scale (ISS), and 7 questions for depressive symptoms. We analyzed the association between step count and pain levels considering a non-linear relationship using a restricted cubic spline model.

Results:

Between June 1, 2018 to June 11, 2020, a total of 6,138 records were identified and a total of 1,323 were analyzed. Participants in the 4th quartile (more than 5793 steps a day) had an increased number of step count significantly associated with less pain in numeric pain scale (mean difference, -0.38; 95%CI, -0.74- -0.02; P=.037), compared to the 1st quartile and the restricted cubic splines for the association between step count and pain scale displayed a steep decline followed by a moderate decrease as the step count increased. However, this association was not observed among those who met the fibromyalgia criteria.

Conclusions:

Step count measured by the “Pain-Note”-based pedometer showed an association with pain levels with an inflection point among individuals with chronic pain, whereas among participants who met the fibromyalgia criteria there was no association. These findings suggest that participants who meet the criteria for fibromyalgia present a different response between walking and pain perception than those in the general chronic pain population.