Table II. —Mean (SD) values of the QBPDS pre- vs. post-rehabilitation for the total (N.=201) sample and for patients improved (GPE=2 or 3; N.=103) vs. stable (GPE=0 or 1; N.=78).

QBPDS	Pretreatment		Post-treatment
	Mean	SD	Mean	SD
Total	32.15	13.22	28.28	13.80
Improved	31.76	12.32	22.86	9.48
Stable	31.82	13.44	30.63	13.63

QBPDS: Quebec Back Pain Disability Scale; GPE: global perceived effect.