Table 2.

Definition of “responders” used in randomised controlled trials (RCTs) of interventions for chronic LBP

Outcome	Definition of ‘responder’	Reference or source	RCTs
Back-specific function (Hannover)	12 % improvement	–	[19]
Back-specific function (Hannover)	20 % improvement	–	[22]
Back-specific function (Oswestry)	Two-grade improvement in one or more functional subsets	–	[25]
Back-specific function (RMDQ)	2-point reduction	[53]	[20, 24]
Back-specific function (RMDQ)	30 % reduction	[54]	[21]
Back-specific function (RMDQ)	50 % reduction	–	[20, 23]
Combined	2-point reduction in VAS and 50 % improvement in general perceived effect	–	[26, 27]
Combined	50 % reduction in median VAS-back, without a drop in daily activities or rise in analgesics; or 25 % reduction in median VAS-back, with a simultaneous rise in daily activities of at least 25 % and a drop in analgesic intake of at least 25 %	–	[28]
Combined	50 % reduction in median VAS-leg without a drop in daily physical activities score, a rise in numerical analgesics rating scale, or both	–	[29]
Combined	No neurologic deficit, improvement in LBOS of >7, improvement in SF-36 bodily pain and physical function of >1 standard deviation	–	[30]
Pain intensity	21 mm reduction on a mean of three visual analogue scales of the MPQ	[55]	[18]
Pain intensity	25 % reduction (VAS)	–	[28, 42]
Pain intensity	30 % reduction (VAS)	[47]	[31, 34, 40, 43, 44]
Pain intensity	33 % improvement on three pain-related items on the Chronic Pain Grade scale	–	[19]
Pain intensity	33 % reduction (VAS)	–	[41]
Pain intensity	50 % reduction (VAS)		[23, 25, 28, 31, 34–36, 39, 40, 42–44, 52]
Pain intensity	60 % reduction (VAS)	–	[37]
Pain intensity	67 % reduction (VAS)	–	[41]
Pain intensity	75 % reduction (VAS)	–	[38, 42]
Pain intensity	100 % reduction (VAS)	–	[32, 33, 37]

RMDQ Roland–Morris Disability Questionnaire, VAS visual analogue scale, LBOS low back outcome scale, MPQ McGill Pain Questionnaire