Table 2. Internal consistency reliability, test-retest reliability, and floor/ceiling effect of the SF-36v2 and the QOL-DAv2.0 (N = 1212).

	Internal consistency reliability	Test-retest reliability†	Floor and ceiling effects [n (%)]‡
	(Cronbach’s α)	(Intra-class correlation, ICC)	Floor effect	Ceiling effect
SF-36v2
Physical component summary (PCS)	0.80	0.86	1 (0.1)	1 (0.1)
Mental component summary (MCS)	0.86	0.85	1 (0.1)	1 (0.1)
Physical functioning (PF)	0.88	0.73	1 (0.1)	221 (18.2)
Role-physical (RP)	0.92	0.75	51 (4.2)	290 (23.9)
Bodily pain (BP)	0.87	0.78	8 (0.7)	366 (30.2)
General health (GH)	0.78	0.87	38 (3.1)	2 (0.2)
Vitality (VT)	0.77	0.85	31 (2.6)	18 (1.5)
Social functioning (SF)	0.73	0.72	21 (1.7)	281 (23.2)
Role-emotional (RE)	0.91	0.79	65 (5.4)	272 (22.4)
Mental health (MH)	0.76	0.79	8 (0.7)	26 (2.1)
QOL-DAv2.0
Physiology (PH)	0.88	0.88	1 (0.1)	5 (0.4)
Psychology (PS)	0.93	0.92	5 (0.4)	112 (9.2)
Society (SO)	0.80	0.89	1 (0.1)	1 (0.1)
Symptoms (ST)	0.92	0.90	1 (0.1)	118 (9.7)
Total score	0.96	0.94	2 (0.2)	1 (0.1)

† Test-retest reliability was assessed in a group of 100 patients.

‡ Floor and ceiling effects [n (%)]: the numbers and percentages of the patients at the lowest and highest possible scores.

Floor effect or ceiling effect ≥ 15% was in bold.