“…For example, while some studies have found tobacco use to be a predictor of poor outcome from fusion surgery (Andersen et al, 2001;LaCaille et al, 2005;Manniche et al, 1994), others have not (Christensen et al, 1999). Similarly, while some studies have found pain drawings to be predictive of a poor outcome from spinal surgery (Dzioba & Doxey, 1984;Takata & Hirotani, 1995), other studies have not (Hagg, Fritzell, Hedlund et al, 2003). An area where research is lacking is to what extent the psychosocial risk factors vary across medical procedures such as SCS, discectomy and fusion.…”