Physiotherapy 96 (2010) 213–221 The influence of psychological factors on pre-operative levels of pain intensity, disability and health-related quality of life in lumbar spinal fusion surgery patients Allan D. Abbott a,b,∗ , Raija Tyni-Lenné a , Rune Hedlund c a Department of Physical Therapy, Karolinska University Hospital, Stockholm, Sweden b Department of Clinical Science, Intervention and Technology, Division of Orthopaedics, Karolinska Institute, Stockholm, Sweden c Institute for Clinical Sciences, Department for Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden Abstract Objectives To assess the extent to which perceived pain and psychological factors explain levels of disability and health-related quality of life (HRQOL) in patients scheduled for lumbar fusion surgery, and to test the hypothesis that relationships between pain intensity, mental health, fear of movement/(re)injury, disability and HRQOL are mediated by cognitive beliefs and appraisals. Design Cross-sectional, correlation study. Setting Orthopaedic outpatient setting in a tertiary hospital. Participants One hundred and seven chronic back pain patients scheduled for lumbar fusion surgery. Measures Visual analogue scale for pain intensity, Short Form 36 mental health subscale, Tampa Scale for Kinesiophobia, Back Beliefs Questionnaire, Self-efficacy Scale, Coping Strategy Questionnaire, Oswestry Disability Index and European Quality of Life Questionnaire. Results The group effect of multiple mediators significantly influenced the relationships between pain intensity and mental health, fear of movement/(re)injury, functional disability and HRQOL. Pain catastrophising significantly mediated the relationship between pain intensity and mental health, control over pain significantly mediated the relationship between mental health and functional disability, self-efficacy and pain outcome expectancy significantly mediated the relationship between mental health and HRQOL, and self-efficacy also significantly mediated the relationship between pain intensity, fear of movement/(re)jury and functional disability. The model explained 28, 30, 52 and 42% of the variation in mental health, fear of movement/(re)injury, functional disability and HRQOL, respectively. Conclusions This study highlights the strong influence and mediation roles of psychological factors on pain, mental health, fear of move- ment/(re)injury, disability and HRQOL in patients scheduled for lumber fusion. Future research should focus on screening as well as pre- and post-operative interventions based on these psychological factors for the potential improvement of lumber fusion surgery outcomes. © 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved. Keywords: Spinal fusion; Disability; Quality of life; Mental disorders; Fear avoidance; Mediation Introduction Since a biopsychosocial approach has been used in the development of a theoretical explanation for chronic pain and disability, psychosocial factors have been suggested to inter- mediate between neurophysiological mechanisms of pain and the experience of pain perception and disability [1]. ∗ Corresponding author at: Department of Physical Therapy, Karolinska University Hospital, Huddinge, Stockholm 14186, Sweden. Tel.: +46 8 585 819 55; fax: +46 8 585 821 90. E-mail address: allan.abbott@karolinska.se (A.D. Abbott). Based on theories of operant and classical behavioural conditioning, early literature from Fordyce et al. [2–4] suggested that maladaptive pain-avoidance behaviours can be learned and persist independent of nocioceptive input. Turk et al. [5] argued the importance of individuals’ beliefs, cognitions and coping skills in the development and maintenance of chronic pain and disability. The work of Lethem et al. [6], Phillips [7] and Waddell et al. [8] emphasised a reciprocal relationship between cognitive and behavioural factors. Moreover, Lethem et al. [6] suggested that confrontation of pain-related fears promotes recovery, while fear avoidance generates physical and psychosocial 0031-9406/$ – see front matter © 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.physio.2009.11.013