Multidisciplinary Treatment in Chronic Widespread Pain
Multidisciplinary Treatment in Chronic Widespread Pain
Of the 361 patients referred to and evaluated by the pain management team, 165 patients fulfilled the inclusion criteria for this study. Of these patients, 138 consented to participate in the study. Reasons for not participating were: dyslexia, not interested in completing the necessary paperwork, too busy or no specific reason. Of these 138 participants, 133 participants provided data at T0. Reasons for missing cases at this stage were: withdrawal from treatment (n=3) and no specific reason (n=2). One hundred twenty participants provided data at T1. Reasons for missing cases at this stage were: no further consent for participation in the study (n=3) or no specific reason (n=10). Participants who dropped-out of the study at T1 did not differ significantly from participants who completed the measurements at T1, except for depression (Mdrop-out = 26.23, SD = 7.36; Mparticipants = 20.78, SD = 8.85; P = 0.02). Baseline characteristics of the participants are shown in Table 1.
Table 2 shows T0 and T1 scores on the outcome measures. Statistically significant improvements after treatment were found for interference of pain (MPI) (P= 0.02) and depression (BDI-II) (P< 0.001). Forty-eight percent of the patients improved on GPE.
The results of the univariate linear regression analyses are shown in Table 3. Predictors with a relationship with the outcome measure of P < 0.20 were used for multiple regression analyses. The correlation coefficients between the potential predictors of the outcome measure pain ranged from .27 (i.e. pain (NRS) and depression (BDI)) to .52 (i.e. pain (NRS) and the impact of fibromyalgia (FIQ)). The relationships between the potential predictors of the outcome measure interference of pain ranged from .18 (self-efficacy (DGSS) and beliefs in consequences (IPQ)) to .67 (i.e. psychological functioning (SCL 90) and anxiety (HADS)). In addition, the relationships between the potential predictors of the outcome measure depression ranged from .21 (i.e. beliefs in timeline (IPQ) and resting (PCI)) to -.31 (i.e. beliefs in personal control (IPQ) and resting (PCI)). Finally, relationships between the potential predictors of the outcome measure global perceived effect ranged from -.20 (i.e. timeline beliefs (IPQ) and treatment control (IPQ)) to .62 (i.e. fatigue (FIQ) and impact of fibromyalgia (FIQ)). Only variables that showed a statistically significant association (at P < 0.05) with change scores in the outcome measures were included in the final model. The results of the multiple linear regression analyses are shown in Table 4. Greater improvement in pain (NRS) was associated with more pain (NRS) at baseline (P < 0.001) and male gender (P = 0.02). Greater improvement in interference of pain in daily life (MPI) was associated with more interference of pain (MPI) at baseline (P < 0.001), less anxiety (HADS) (P = 0.03), stronger beliefs in personal control (IPQ) (P < 0.004), less beliefs in consequences (IPQ) (P < 0.001), male gender (P = 0.02), and a higher level of education (P= 0.003, P = 0.03). Greater improvement in depression (BDI-II) was associated with more depressive symptoms at baseline (P < 0.001), stronger beliefs in personal control (P < 0.001), and a higher level of education (P = 0.02, P = 0.04). Better global perceived effect was associated with less pain (NRS) (P = 0.01), less fatigue (FIQ) (P = 0.03), and a higher level of education (P = 0.03). The explained variance (R) for the final models ranged from 25.7% to 38.1%. In summary, five of our eight hypotheses were confirmed while one hypothesis was partly confirmed (see Table 5).
In the secondary analyses, adjustment for treatment frequency in the multiple variable models only affected the model of GPE. After adjustment, global perceived effect was only associated with pain (NRS) (OR = .72; 95% CI, .58 to 90), fatigue and education were no longer factors in the final model.
Results
Study Population
Of the 361 patients referred to and evaluated by the pain management team, 165 patients fulfilled the inclusion criteria for this study. Of these patients, 138 consented to participate in the study. Reasons for not participating were: dyslexia, not interested in completing the necessary paperwork, too busy or no specific reason. Of these 138 participants, 133 participants provided data at T0. Reasons for missing cases at this stage were: withdrawal from treatment (n=3) and no specific reason (n=2). One hundred twenty participants provided data at T1. Reasons for missing cases at this stage were: no further consent for participation in the study (n=3) or no specific reason (n=10). Participants who dropped-out of the study at T1 did not differ significantly from participants who completed the measurements at T1, except for depression (Mdrop-out = 26.23, SD = 7.36; Mparticipants = 20.78, SD = 8.85; P = 0.02). Baseline characteristics of the participants are shown in Table 1.
Changes in Depression, Interference of Pain, Pain and Global Perceived Effect
Table 2 shows T0 and T1 scores on the outcome measures. Statistically significant improvements after treatment were found for interference of pain (MPI) (P= 0.02) and depression (BDI-II) (P< 0.001). Forty-eight percent of the patients improved on GPE.
Predictors of Outcome
The results of the univariate linear regression analyses are shown in Table 3. Predictors with a relationship with the outcome measure of P < 0.20 were used for multiple regression analyses. The correlation coefficients between the potential predictors of the outcome measure pain ranged from .27 (i.e. pain (NRS) and depression (BDI)) to .52 (i.e. pain (NRS) and the impact of fibromyalgia (FIQ)). The relationships between the potential predictors of the outcome measure interference of pain ranged from .18 (self-efficacy (DGSS) and beliefs in consequences (IPQ)) to .67 (i.e. psychological functioning (SCL 90) and anxiety (HADS)). In addition, the relationships between the potential predictors of the outcome measure depression ranged from .21 (i.e. beliefs in timeline (IPQ) and resting (PCI)) to -.31 (i.e. beliefs in personal control (IPQ) and resting (PCI)). Finally, relationships between the potential predictors of the outcome measure global perceived effect ranged from -.20 (i.e. timeline beliefs (IPQ) and treatment control (IPQ)) to .62 (i.e. fatigue (FIQ) and impact of fibromyalgia (FIQ)). Only variables that showed a statistically significant association (at P < 0.05) with change scores in the outcome measures were included in the final model. The results of the multiple linear regression analyses are shown in Table 4. Greater improvement in pain (NRS) was associated with more pain (NRS) at baseline (P < 0.001) and male gender (P = 0.02). Greater improvement in interference of pain in daily life (MPI) was associated with more interference of pain (MPI) at baseline (P < 0.001), less anxiety (HADS) (P = 0.03), stronger beliefs in personal control (IPQ) (P < 0.004), less beliefs in consequences (IPQ) (P < 0.001), male gender (P = 0.02), and a higher level of education (P= 0.003, P = 0.03). Greater improvement in depression (BDI-II) was associated with more depressive symptoms at baseline (P < 0.001), stronger beliefs in personal control (P < 0.001), and a higher level of education (P = 0.02, P = 0.04). Better global perceived effect was associated with less pain (NRS) (P = 0.01), less fatigue (FIQ) (P = 0.03), and a higher level of education (P = 0.03). The explained variance (R) for the final models ranged from 25.7% to 38.1%. In summary, five of our eight hypotheses were confirmed while one hypothesis was partly confirmed (see Table 5).
In the secondary analyses, adjustment for treatment frequency in the multiple variable models only affected the model of GPE. After adjustment, global perceived effect was only associated with pain (NRS) (OR = .72; 95% CI, .58 to 90), fatigue and education were no longer factors in the final model.
