It is believed that patients' expectancies about the effectiveness of treatment influence their treatment outcomes, but the working mechanism is rarely studied in low back pain patients. Theoretical models suggest that adherence to treatment may be an important pathway. The aim of this study was to assess the mediating role of adherence to treatment in the relationship between expectancies and the outcomes of recovery and pain intensity in patients with acute low back pain. This study used data from a randomized placebo controlled trial of paracetamol for acute low back pain. Expectancies were measured with the Credibility Expectancy Questionnaire (CEQ). Adherence was measured with a medication diary. Pain intensity was recorded daily in a diary on a 0-10 pain scale and recovery was defined as the first of seven consecutive days scoring 0 or 1 on a 6 point pain scale. Cox regression (dependent variable: recovery) and linear mixed model analyses (dependent variable: daily pain intensity scores) were performed. The "difference in coefficients" approach was used to establish mediation. 1573 participants were included in current analyses. There was a small but highly significant relationship between expectancies and outcomes; 3.3% of the relationship between expectancies and recovery and 14.2% of the relationship between expectancies and pain intensity was mediated by adherence to treatment. The current study does not convincingly support the theory that adherence is a key pathway in the relationship between treatment outcome expectancies and recovery and pain intensity in this acute low back pain population.
AD - 1Department of Epidemiology and Biostatistics and the EMGO institute for Health and Care research, VU University Medical Center, Amsterdam 2The George Institute for Global Health, Sydney Medical School, University of Sydney, Sydney Australia 3Hunter Medical Research Institute, School of Medicine and Public Health, University of Newcastle, Newcastle, Australia 4Department of Health Sciences, Faculty of Earth and Life Sciences, EMGO+ Institute for Health and Care Research, VU University, Amsterdam. AN - 25906348 BT - Pain DP - NLM ET - 2015/04/24 LA - Eng LB - MSK M1 - 8 N1 - Haanstra, Tsjitske MIt is believed that patients' expectancies about the effectiveness of treatment influence their treatment outcomes, but the working mechanism is rarely studied in low back pain patients. Theoretical models suggest that adherence to treatment may be an important pathway. The aim of this study was to assess the mediating role of adherence to treatment in the relationship between expectancies and the outcomes of recovery and pain intensity in patients with acute low back pain. This study used data from a randomized placebo controlled trial of paracetamol for acute low back pain. Expectancies were measured with the Credibility Expectancy Questionnaire (CEQ). Adherence was measured with a medication diary. Pain intensity was recorded daily in a diary on a 0-10 pain scale and recovery was defined as the first of seven consecutive days scoring 0 or 1 on a 6 point pain scale. Cox regression (dependent variable: recovery) and linear mixed model analyses (dependent variable: daily pain intensity scores) were performed. The "difference in coefficients" approach was used to establish mediation. 1573 participants were included in current analyses. There was a small but highly significant relationship between expectancies and outcomes; 3.3% of the relationship between expectancies and recovery and 14.2% of the relationship between expectancies and pain intensity was mediated by adherence to treatment. The current study does not convincingly support the theory that adherence is a key pathway in the relationship between treatment outcome expectancies and recovery and pain intensity in this acute low back pain population.
PY - 2015 SN - 1872-6623 (Electronic)