Psychological Covariates of Longitudinal Changes in Back-related Disability in Patients Undergoing Acupuncture

Objectives: To identify psychological covariates of longitudinal changes in back-related disability in patients undergoing acupuncture. Materials and Methods: A longitudinal postal questionnaire study was conducted with data collection at baseline (pretreatment), 2 weeks, 3, and 6 months later. A total of 485 patients were recruited from 83 acupuncturists before commencing acupuncture for back pain. Questionnaires measured variables from 4 theories (fear-avoidance model, common-sense model, expectancy theory, social-cognitive theory), clinical and sociodemographic characteristics, and disability. Longitudinal multilevel models were constructed with disability over time as the outcome. Results: Within individuals, reductions in disability (compared with the person's individual mean) were associated with reductions in: fear-avoidance beliefs about physical activity (beta=0.11, P<0.01) and work (beta=0.03, P<0.05), catastrophizing (beta=0.28, P<0.05), consequences (beta=0.28, P<0.01), concerns (beta=0.17, P<0.05), emotions (beta=0.16, P<0.05), and pain identity (beta=0.43, P<0.01). Within-person reductions in disability were associated with increases in: personal control (beta=-0.17, P<0.01), comprehension (beta=-0.11, P<0.05) and self-efficacy for coping (beta=-0.04, P<0.01). Between individuals, people who were less disabled had weaker fear-avoidance beliefs about physical activity (beta=0.12, P<0.01), had more self-efficacy for coping (beta=-0.07, P<0.01), perceived less severe consequences of back pain (beta=0.87, P<0.01), had more positive outcome expectancies (beta=-0.30, P<0.05), and appraised acupuncture appointments as less convenient (beta=0.92, P<0.05). Discussion: Illness perceptions and, to a lesser extent, self-efficacy and expectancies can usefully supplement variables from the fear-avoidance model in theorizing pain-related disability. Positive changes in patients' beliefs about back pain might underpin the large nonspecific effects of acupuncture seen in trials and could be targeted clinically.