Psychosocial predictors of health-related quality of life and health service utilisation in people with chronic low back pain.

Psychological and social factors have been shown, separately, to predict outcome in individuals with chronic low back pain. Few previous studies, however, have integrated both psychological and social factors, using prospective study of clinic populations of low back pain patients, to identify which are the most important targets for treatment. One hundred and eight patients with chronic low back pain, newly referred to an orthopaedic outpatient clinic, completed assessments of demographic characteristics, details of back pain, measures of anxiety and depression (Hospital Anxiety and Depression Scale, HADS), fearful beliefs about pain (Fear Avoidance Beliefs Questionnaire), social stresses (Life Events and Difficulties Schedule) and physical aspects of health-related quality of life [SF-36 Physical Component summary Score scale (PCS)]. Six months later subjects completed the SF-36 PCS and the number of healthcare contacts during follow-up was recorded. Independent predictors of SF-36 PCS at 6-month follow-up were duration of pain [(standardised regression coefficient (beta)=-0.18, p=0.04), HADS score (beta)=-0.27, p=0.003] and back pain related social difficulties (beta=-0.42, p<0.0005). Number of healthcare contacts over the 6 months ranged from 1 to 29, and was independently predicted by perceived cause of pain [Incident Rate Ratio (IRR)=1.46, p=0.03], Fear Avoidance Beliefs about work (IRR=1.02, p=0.009) and back pain related social difficulties (IRR=1.16, p=0.03). To conclude, anxiety, depression, fear avoidance beliefs relating to work and back pain related stresses predict impairment in subsequent physical health-related quality of life and number of healthcare contacts. Interventions targeting these psychosocial variables in clinic patients may lead to improved quality of life and healthcare costs.