Quantifying pain intensity is challenging, particularly for patients with chronic pain. The visual analog scale (VAS) is limited by ceiling effects that often leave patients with no ability to quantify worsening pain. The goal of this study was to determine whether the general Labeled Magnitude Scale (gLMS) can be feasibly used to measure pain clinically while overcoming limitations of the VAS.
Eighty patients (mean age, 53.7 yrs) scheduled for evaluation of a painful complaint were asked to rate their current pain using the gLMS and the VAS. The time necessary to administer the gLMS was recorded to determine feasibility. The difference in rating between the two scales (VAS and gLMS) was the main outcome measure.
After scaling and rounding off the gLMS scores for direct comparison, it was found that the gLMS scores were significantly lower than the corresponding VAS scores by a mean of 1.78 (P < 0.001). The mean time to administer the gLMS was 2.66 mins.
These results suggest that the gLMS has great potential and can be feasibly used to measure pain intensity clinically. The gLMS scores were consistently lower than the VAS scores, thus reducing the ceiling effect and allowing range at the high end of the scale for rating worsening pain.