Table 3.
Multilevel Regressions of Momentary Associations Between Changes in Pain and Fatigue and Subsequent (Lagged) Changes in Activity Pacing
| Random Effects | |||||||||
| Pain→Pacing | Fatigue→Pacing | ||||||||
| Covariance Parameter |
Subject | Estimate | SE | Z | p | Estimate | SE | Z | p |
| Intercept CS | ID | 5.25 | .66 | 7.94 | <.0001 | 5.26 | .66 | 7.97 | <.0001 |
| CS | ID | −0.02 | .0006 | −32.29 | <.0001 | −.02 | .0005 | −32.47 | <.0001 |
| CS | DAY(ID) | 1.00 | .12 | 8.68 | <.0001 | .99 | .11 | 8.75 | <.0001 |
| Residual | • | 3.41 | .11 | 32.29 | <.0001 | 3.40 | .11 | 32.47 | <.0001 |
| Fixed Effects | |||||||||
| Pain→Pacing | Fatigue→Pacing | ||||||||
| Effect | β | SE | t | p | β | SE | t | p | |
| Intercept | 5.70 | .32 | 17.74 | <.0001 | 5.81 | .31 | 18.48 | <.0001 | |
| Level 1 (df = pain 2699, fatigue 2720) | |||||||||
| Momentary pain/fatigue | .11 | .03 | 4.16 | <.0001 | .11 | .03 | 3.74 | .0002 | |
| Level 3 (df = pain 145, fatigue 146) | |||||||||
| WOMAC pain severity | .08 | .07 | 1.26 | .21 | |||||
| BFI fatigue severity | .16 | .12 | 1.31 | .19 | |||||
| Age | .07 | .04 | 1.95 | .05 | .07 | .04 | 1.93 | .06 | |
| Sex | −.06 | .41 | −.13 | .89 | −.17 | .40 | −.43 | .67 | |
| Body Mass Index | .02 | .04 | .57 | .57 | .03 | .04 | .71 | .48 | |
| Six Minute Walk (feet) | −.002 | .001 | −2.31 | .02 | −.002 | .001 | −2.37 | .02 | |
| Average Activity | .001 | .002 | .51 | .61 | .001 | .002 | .47 | .64 | |
| Illness Burden | .02 | .05 | .53 | .60 | .02 | .05 | .47 | .64 | |
| CES-D | .04 | .03 | 1.60 | .11 | .03 | .03 | 1.08 | .28 | |
Note. A compound symmetry matrix was used to model the error variance on the DV. Level 1 variables are person-centered. Level 3 variables are sample-centered.
ID = subject identifier. CES-D = Center for Epidemiological Studies Depression Scale; WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index; Illness Burden = # self-report health problems/symptoms, 41 possible);
*
average of all momentary self-report ratings over the study period