Table 2.
Summary of separate parallel mediation analyses for each disability measure with change in pain catastrophizing scale, fear and avoidance beliefs questionnaire, and arthritis self-efficacy scale mediating the effects of change in pain intensity on change in functional disability.
| IV | Total effect (path c) | Direct effect (path c') | Indirect effect* | ES | St. indirect effect | DV |
|---|---|---|---|---|---|---|
| Model 1 | ||||||
| ΔPCS (M1) | 1.11 (0.39, 1.83)† | 0.35 (−0.39, 1.10) | 0.37 (0.07, 0.82)† | 33% | 0.12 | |
| ΔFABQ (M2) | 1.11 (0.39, 1.83)† | 0.35 (−0.39, 1.10) | 0.13 (−0.17, 0.45) | 12% | 0.04 | |
| ΔASES (M3) | 1.11 (0.39, 1.83)† | 0.35 (−0.39, 1.10) | 0.26 (−0.08, 0.66) | 24% | 0.09 | ΔWSAS (n = 69) |
| Model 2 | ||||||
| ΔPCS (M1) | 0.63 (0.18, 1.09)† | 0.18 (−0.29, 0.67) | −0.02 (−0.19, 0.18) | 3% | −0.01 | |
| ΔFABQ (M2) | 0.63 (0.18, 1.09)† | 0.18 (−0.29, 0.67) | 0.20 (0.01, 0.47)† | 32% | 0.11 | |
| ΔASES (M3) | 0.63 (0.18, 1.09)† | 0.18 (−0.29, 0.67) | 0.25 (0.04, 0.55)† | 40% | 0.13 | ΔPFS (n = 69) |
| Model 3 | ||||||
| ΔPCS (M1) | 0.23 (−0.05, 0.52) | −0.04 (−0.35, 0.28) | 0.00 (−0.08, 0.08) | 0% | 0.00 | |
| ΔFABQ (M2) | 0.23 (−0.05, 0.52) | −0.04 (−0.35, 0.28) | 0.10 (−0.02, 0.22) | 43% | 0.08 | |
| ΔASES (M3) | 0.23 (−0.05, 0.52) | −0.04 (−0.35, 0.28) | 0.17 (0.01, 0.36)† | 74% | 0.15 | ΔBPS (n = 61) |
The indirect effect quantifies how much 2 cases that differ by one unit on pain intensity (∆API) are estimated to differ on disability (∆WSAS, ∆PFS, and ∆BPS) through each putative mediator; ES = ratio of the indirect effect to the total effect as a measure of effect size.
95% confidence interval that does not include 0.
ASES, Arthritis Self-Efficacy Scale; BPS, back performance scale; DV, dependent variable; FABQ, fear-avoidance beliefs questionnaire; IV, independent variable; Mx, mediator(s); PCS, pain catastrophizing scale; PFS, physical functioning scale; WSAS, Work and Social Adjustment Scale.