Preliminary validation of the Michigan Body Map

Abstract

We developed the Michigan Body Map (MBM) as a self-report measure to assess body areas where chronic pain is experienced and to specifically quantify the degree of widespread body pain when assessing for centralized pain features (eg, fibromyalgia-like presentation). A total of 402 patients completed the measure in 5 distinct studies to support the validation of the original and a revised version of the MBM. Administration is rapid 39 to 44 seconds, and errors for the original MBM were detected in only 7.2% of the possible body areas. Most errors underestimated the number of painful areas or represented confusion in determining the right vs left side. The MBM was preferred (P = 0.013) and felt to better depict pain location (P = 0.001) when compared with the Widespread Pain Index checklist of the 2011 Fibromyalgia Survey Criteria, but participants did not express any preference between the MBM and Brief Pain Inventory body map. Based on the data from the first 3 studies, a revised version of the MBM was created including a front and back body image and improved guidance on right-sidedness vs left. The revised MBM was preferred when compared with the original and was more accurate in depicting painful body areas (P = 0.004). Furthermore, the revised MBM showed convergent and discriminant validity with other self-report measures of pain, mood, and function. In conclusion, the MBM demonstrated utility, reliability, and construct validity. This new measure can be used to accurately assess the distribution of pain or widespread bodily pain as an element of the fibromyalgia survey score.

Figures

Figure 1. Comparisons between the Michigan Body Map (MBM) and the widespread pain index (WPI) from the 2011 Survey Criteria for Fibromyalgia and the body map of the Brief Pain Inventory (BPI)

Patients significantly preferred the MBM to the WPI and felt that the MBM better allowed for depiction of their painful body areas. Although not statistically significant patients described the MBM as easier to complete when compared to the WPI. There were no significant differences in the same assessments between the MBM and BPI body map.

Figure 2. Comparison of the original and revised Michigan Body Map (MBM)

When compared to the original MBM, the revised MBM was preferred and felt to better depict the patients’ painful body areas. The revised MBM was also felt to better represent right and left sided body areas. There were no differences in which body map was deemed easier to complete.