Table 1.

Summary of Established Minimal Important Difference for Generic Measures

Instrument (No. Items)	Disease Group	MID Approach	Effect Size (Small = 0.2–0.5; Moderate = 0.5–0.8; Large ≥ 0.8)	MID Values	Reference
FACT-G	FACT-An-cancer patients	Anchor and distribution	0.25–0.67	4	Cella et al. (2002b)
FACT-G	FACT-B breast cancer	Anchor and distribution	0.31–0.54	5–6	Eton et al. (2004)
SF-12-PCS		Anchor based	Not reported	6.8	Schmitt and De Fabio (2004)
FACT-head and neck		Anchor based	Not reported	4–8	Ringash et al. (2004, 2007)
SF-6D EQ-5D	Multiple patient groups	Anchor and distribution	0.12–0.97 0.04–0.44		Walters and Brazier (2005)
SF-6D	Spinal cord	Anchor based	0.23 and 0.86	0.03–0.10	Lee et al. (2008)
SF-36 and SGRQ		Anchor and distribution	Not reported	SF-36 = 2–4 SGRQ = 5–8	Swigris et al. (2010)