Figure 2: Back pain intensity ratings over a six-week, dose escalating, placebo or DCS treatment. (a) Across subject average back pain, assessed on the primary outcome measure of 0–10 numeric rating scale. (b) Within subject change in pain, relative to baseline, using the 0–10 numeric rating scale. Adapted from Schnitzer ⁴⁴. Note that the trial did not meet its primary endpoint because separation from placebo was not seen at all dosages/timepoints.