Definition of Nonresponse to Analgesic Treatment of Arthritic Pain: An Analytical Literature Review of the Smallest Detectable Difference, the Minimal Detectable Change, and the Minimal Clinically Important Difference on the Pain Visual Analog Scale

Table 1

Smallest detectable difference (SDD) of the 0–100 mm pain VAS reported in studies of rheumatoid arthritis.

Study	𝑁	Baseline pain VAS score^a		SDD
		Mean	SD	Absolute value^b	As % of pain VAS score
Uhlig et al. 2009 [10]	28	29.5	23.7	−18.6, +26.0	±76%
Pincus et al. 2008 [11]	264	39.8^c	29.1^c	−19.0, +19.4	±48%
Lassere et al. 2001 [12]	24	37	—	−20, +16.3	±49%

SD: standard deviation; SDD: smallest detectable difference; VAS: visual analog scale.
^a0–100 mm pain VAS from 0, no pain, to 100, very severe pain.
^bAll 10-mm scale values were converted to a 100-point scale by multiplying by ten.
^cValues provided by T. Pincus and C. Swearingen for the “line 1” scores (see original article).