Stefan Elbers

95 Self-management for patients with chronic pain Immediate Post-Intervention Comparisons Physical Function. For eight of the 11 studies that reported outcomes on physical function we were able to calculate standardized mean differences. Statistical pooling was considered appropriate despite a high I 2 , as a sensitivity analysis revealed that the heterogeneity was mainly attributable to one study (Asenlof et al., 2005), and that the confidence intervals showed substantial overlap. The pooled effect was calculated with Hedges’ (adjusted) g and was significant; SMD = −0.28 [−0.52, −0.03], z = 2.23, p = 0.03 (see Figure 2). When this effect is re-expressed on a Pain Disability Index (PDI), using the baseline standard deviation ( SD = 14.7) of the control group of Asenlof et al. (2005), this effect corresponds to a between- group difference of 4.12 points on a PDI favouring the self-management group. This is lower than the minimal clinically important change of 8.5 points that was calculated by Soer et al. (2012). The between-group comparison of post minus pre scores of Manning et al. (2014) was not significant; SMD = −0.40 [−0.82, 0.02], z = 1.88, p = 0.06. Burckhardt et al. (1994) and Dworkin et al. (2002) reported no between-group differences post-intervention. Taal et al. (1993) found a statistically significant difference on the Modified Health Assessment Questionnaire (M-HAQ), with the experimental group showing a mean decrease of 0.01 points and the control group showing a mean increase of 0.16 points compared to baseline scores (p < 0.05). Figure 2. Post Treatment Comparison of Self-Management Intervention Versus Control on Physical Function.