Table 3.

Minimal important difference estimates for the pain visual analog scale (VAS; 0–100 mm).

Patient-rated Overall StatusPain VAS Change, mean (SD)95% CIEffect Sizep
Much better (n = 10)−42.1 (34.2)−66.5 to −17.61.46< 0.001
Somewhat better (n = 30)−11.9 (30.8)−23.4 to −0.40.410.07
Same (n = 110)−3.2 (20.9)−7.1 to 0.80.11
Somewhat worse (n = 51)6.8 (22.7)0.4 to 13.10.230.007
Much worse (n = 11)15.3 (19.5)2.2 to 28.40.530.005
  • 0 is no pain, 100 is “very severe pain”. Pain VAS change score = Pain VAS score at most recent visit – score at previous visit. Negative score indicates improvement.