In the present study, a main findin

In the present study, a main finding is the sustained 10%
improvement on the PCS (76.3% of the population) up to 5 months
and on GPE (60.3%) up to 12 months. For MCS this 10% improvement
is slightly less (20.6%) at 5 months, but a mean of 50 (SD of 10)
represents normal health and function (Walsh et al., 2003). Some
patients reported no improvement on GPE at 5 and 12-months
follow-up (15% and 20.6%, respectively).
The present study shows that improvement in quality of life (on
SF-36 MCS) at 5-months follow-up was associated with patients'
characteristics and psychological factors. At 5-months, improvement
on quality of life (on SF-36 PCS) and GPE was associated with
patients' characteristics, physical examination, work-related factors
and psychological factors. For GPE, clinical status was also associated
with improvement.
At 12-months follow-up GPE was associated with patients'
characteristics, clinical status, physical examination and workrelated
factors. The sensitivity analyses showed overall similarity
for the prognostic factors. The prognostic models provide