Table 2.
Associations of DAS28-related variables with pressure pain thresholds and fibromyalgia classification
| Index | Medial Tibia PPT | Fibromyalgia (FM) classification | |||||
|---|---|---|---|---|---|---|---|
| B (95% CI) | p | RA with FM | RA (no FM) | p | Difference | Effect size | |
| TJC | − 0.39 (− 0.63 to − 0.15) | 0.002 | 14 (7) | 8 (6) | 0.01 | 5.3 | 0.75 |
| VAS-GH | − 0.37 (− 0.61 to − 0.13) | 0.003 | 67 (19) | 42 (19) | < 0.001 | 25 | 1.09 |
| SJC | 0.03 (− 0.23 to 0.28) | 0.834 | 1 (1) | 1 (2) | 0.742 | 0.15 | 0.1 |
| ESR | −0.10 (− 0.36 to 0.17) | 0.464 | 23 (16) | 20 (11) | 0.51 | 2.7 | 0.2 |
| DAS28 | − 0.53 (− 0.77 to − 0.29) | < 0.001 | 5.2 (0.8) | 4.4 (0.8) | 0.001 | 0.79 | 0.93 |
| DAS28-P | −0.41 (− 0.62 to − 0.13) | 0.003 | 0.56 (0.11) | 0.48 (0.09) | 0.008 | 0.09 | 0.81 |
| Tender-swollen difference | −0.38 (− 0.62 to − 0.15) | 0.002 | 12 (8) | 7 (6) | 0.011 | 5.5 | 0.76 |
| Tender:swollen ratio | −0.48 (− 0.79 to − 0.18) | 0.003 | 8.4 (7.0) | 6.2 (5.9) | 0.363 | 2.1 | 0.33 |
Data from PPT study, n = 45. Linear regression between medal tibial pressure pain thresholds (PPT) and DAS28-related variables (lower values of PPTs indicate greater pain sensitivity). Means (sd); T-Tests and Cohens d effect size for differences between patients with RA ± fibromyalgia (FM). TJC tender joint count, SJC swollen joint count, ESR erythrocyte sedimentation rate, VAS-GH visual analogue scale-general health. DAS28-P = proportion of DAS28-ESR attributable to patient-reported components. No corrects were performed for multiple comparisons. Statistically significant findings highlighted in bold