Introduction
Materials and methods
Design
Setting and study sample
Randomisation, treatment arms, implementation and masking of the study groups
Randomisation
Group assignment
Implementation
Intervention
Psychological intervention
Recommended pharmacological treatment
Treatment as usual at the primary care level
Measurements
Main outcome variables
Secondary variables
Sociodemographic variables
Clinical variables
Psychiatric interview
Hamilton Rating Scale for Depression
Hamilton Anxiety Rating Scale
Pain Visual Analogue Scale
Chronic Pain Acceptance Questionnaire
Fibromyalgia Impact Questionnaire
EuroQoL-5D questionnaire (Spanish version)
Statistical methods
Sample size
Analysis strategy
Ethical aspects of the study
Results
Sample recruitment
Baseline demographic and clinical characteristics
Sociodemographic variables | Cognitive behaviour therapy group (N= 57) | RPT group (N= 56) | TAU group (N= 55) | Statistics |
---|---|---|---|---|
Females, n (%) | 54 (94.7%) | 52 (92.9%) | 53 (96.4%) | X2 = 0.674 |
df = 3 | ||||
P = 0.714 | ||||
Mean age, years (± SD) | 46.35 (6.71) | 47.12 (6.25) | 47.04 (6.53) | F = 0.240 |
df = 165 | ||||
P = 0.787 | ||||
Marital status, n (%) | X2 = 0.279 | |||
df = 4 | ||||
P = 0.991 | ||||
Married or in a relationship | 40 (70.2%) | 40 (71.4%) | 37 (67.3%) | |
Single | 9 (15.8%) | 9 (16.1%) | 10 (18.2%) | |
Separated or divorced | 8 (14%) | 7 (12.5%) | 8 (14.5%) | |
Widowed | 0 (0%) | 0 (0%) | 0 (0%) | |
Ethnic group, n (%) | P = 1 | |||
European | 57 (100%) | 57 (100%) | 57 (100%) | |
Living arrangement, n (%) | X2 = 1.481 | |||
df = 8 | ||||
P = 0.993 | ||||
Living alone | 4 (7.0%) | 4 (7.1%) | 6 (10.9%) | |
Living with spouse or partner | 8 (14.0%) | 9 (16.1%) | 8 (14.5%) | |
Living with offspring and/or spouse/partner | 34 (59.6%) | 30 (53.6%) | 31 (56.4%) | |
Living with other relatives | 5 (8.8%) | 7 (12.5%) | 5 (9.1%) | |
Other | 6 (10.5%) | 6 (10.7%) | 5 (9.1%) | |
Educational level, n (%) | X2 = 1.578 | |||
df = 4 | ||||
P = 0.813 | ||||
Illiterate | 0 (0%) | 0 (0%) | 0 (0%) | |
Primary school | 23 (40.4%) | 23 (41.1%) | 28 (50.9%) | |
Secondary school | 23 (40.4%) | 22 (39.3%) | 18 (32.7%) | |
University | 11 (19.3%) | 11 (19.6%) | 9 (16.4%) | |
Employment status, n (%) | X2 = 1.295 | |||
df = 8 | ||||
P = 0.996 | ||||
Unemployed | 19 (29.8%) | 15 (26.8%) | 15 (27.3%) | |
Paid employment | 9 (15.8%) | 11 (19.6%) | 9 (16.4%) | |
On sick leave from paid employment | 13 (22.8%) | 12 (21.4%) | 14 (25.5%) | |
Retired/pensioner | 7 (12.3%) | 6 (10.7%) | 8 (14.5%) | |
Permanent disability | 11 (19.3%) | 12 (21.4%) | 9 (16.4%) | |
Income | X2 = -10.04 | |||
df = 4 | ||||
P = 0.40 | ||||
< MS (600€/month) | 15 (26.3%) | 15 (26.8%) | 27 (49.1%) | |
1 to 2 MS | 24 (42.1%) | 23 (41.1%) | 20 (36.4%) | |
> 2 to 4 MS | 18 (31.6%) | 18 (32.1%) | 8 (14.5%) | |
> 4 MS | 0 (0%) | 0 (0%) | 0 (0%) | |
Clinical variables | ||||
Mean years since diagnosis (± SD) | 12.91 (7.15) | 11.23 (3.85) | 11.69 (4.02) | F = 1.544 |
df = 165 | ||||
P = 0.217 | ||||
Preference for psychotherapy, n (%) | 28 (49.1%) | 26 (46.4%) | 27 (49.1%) | X2 = 0.107 |
df = 2 | ||||
P = 0.948 | ||||
Comorbid major depressive disorder, n (%) | 27 (47.4%) | 26 (46.4%) | 30 (54.5%) | X2 = 0.874 |
df = 2 | ||||
P = 0.646 | ||||
Sexual abuse, n (%) | 4 (7.0%) | 7 (12.5%) | 11 (14.5%) | X2 = 1.70 |
df = 2 | ||||
P = -0.427 | ||||
Currently engaged in litigation, n (%) | 17 (29.8%) | 12 (21.4%) | 16 (29.1%) | X2 = 1.23 |
df = 2 | ||||
P = 0.539 |
Outcome measures | Mean CBT (± SD) | Mean RPT (± SD) | Mean TAU (± SD) | F-value | P-value | ηp2 | Pairwise comparisons | Cohen's d CBT vs RPT | Cohen's d CBT vs TAU | Cohen's d RPT vs TAU |
---|---|---|---|---|---|---|---|---|---|---|
PCS total score (0 to 52) | ||||||||||
Baseline | 34.13 (9.29) | 32.19 (7.05) | 31.23 (7.18) | |||||||
Posttreatment | 24.79 (7.41) | 31.36 (7.10) | 31.47 (6.90) | 133.34 | 0.001 | 0.63 | 1 < 2, 3 | 0.91 | 0.93 | 0.02 |
Six-month follow-up | 25.50 (7.24) | 30.64 (6.75) | 32.74 (7.04) | 144.33 | 0.001 | 0.65 | 1 < 2 < 3 | 0.73 | 1.01 | 0.30 |
PCS-Rumination (0 to 16) | ||||||||||
Baseline | 11.87 (3.08) | 11.08 (2.57) | 10.92 (2.77) | |||||||
Posttreatment | 8.82 (2.47) | 10.68 (2.53) | 11.09 (2.60) | 100.82 | 0.001 | 0.56 | 1 < 2, 3 | 0.74 | 0.90 | 0.16 |
Six-month follow-up | 9.02 (2.46) | 10.28 (2.50) | 11.34 (2.61) | 87.82 | 0.001 | 0.53 | 1 < 2 < 3 | 0.51 | 0.91 | 0.42 |
PCS-Magnification (0 to 12) | ||||||||||
Baseline | 6.38 (2.63) | 6.23 (2.40) | 5.92 (2.22) | |||||||
Posttreatment | 5.18 (2.27) | 6.15 (2.48) | 6.19 (2.23) | 33.08 | 0.001 | 0.30 | 1 < 2, 3 | 0.41 | 0.45 | 0.02 |
Six-month follow-up | 5.59 (2.32) | 6.34 (2.42) | 6.62 (2.27) | 23.65 | 0.001 | 0.23 | 1 < 2 < 3 | 0.32 | 0.45 | 0.12 |
PCS-Helplessness (0 to 24) | ||||||||||
Baseline | 15.89 (5.07) | 14.89 (3.98) | 14.57 (4.13) | |||||||
Posttreatment | 10.79 (4.04) | 14.55 (3.98) | 14.36 (3.99) | 74.29 | 0.001 | 0.49 | 1 < 2, 3 | 0.94 | 0.90 | 0.05 |
Six-month follow-up | 10.95 (4.01) | 14.02 (3.85) | 14.94 (4.27) | 68.04 | 0.001 | 0.46 | 1 < 2 < 3 | 0.78 | 0.96 | 0.23 |
CPAQ (0 to 120) | ||||||||||
Baseline | 49.00 (10.33) | 44.40 (8.90) | 44.45 (10.80) | |||||||
Posttreatment | 51.30 (9.53) | 43.36 (9.00) | 43.15 (10.86) | 33.07 | 0.001 | 0.29 | 1 > 2, 3 | 0.86 | 0.80 | 0.02 |
Six-month follow-up | 50.46 (9.37) | 43.47 (8.85) | 42.53 (10.40) | 24.97 | 0.001 | 0.24 | 1 > 2, 3 | 0.77 | 0.80 | 0.10 |
HAM-D (0 to 50) | ||||||||||
Baseline | 14.47 (3.93) | 14.94 (4.03) | 14.09 (4.64) | |||||||
Posttreatment | 7.78 (2.46) | 7.98 (1.80) | 8.17 (2.25) | 2.17 | 0.12 | 0.03 | ns | 0.09 | 0.17 | 0.09 |
Six-month follow-up | 7.91 (2.50) | 8.19 (1.96) | 8.57 (2.47) | 4.05 | 0.02 | 0.05 | 1 < 3 | 0.12 | 0.27 | 0.17 |
HARS (0 to 56) | ||||||||||
Baseline | 10.84 (4.27) | 11.22 (3.75) | 9.50 (2.98) | |||||||
Posttreatment | 7.09 (2.96) | 7.11 (2.39) | 7.40 (2.18) | 9.71 | 0.001 | 0.11 | 1, 2 < 3 | 0.01 | 0.12 | 0.13 |
Six-month follow-up | 7.25 (3.02) | 7.39 (2.57) | 7.58 (2.07) | 8.49 | 0.001 | 0.10 | 1, 2 < 3 | 0.05 | 0.13 | 0.08 |
PVAS (0 to 100) | ||||||||||
Baseline | 64.20 (10.78) | 68.13 (9.84) | 64.72 (10.44) | |||||||
Posttreatment | 36.88 (8.29) | 37.14 (10.53) | 38.68 (7.48) | 2.25 | 0.109 | 0.03 | ns | 0.03 | 0.23 | 0.17 |
Six-month follow-up | 40.68 (10.93) | 40.54 (9.61) | 44.34 (8.56) | 7.48 | 0.001 | 0.09 | 2 < 3 | 0.01 | 0.37 | 0.42 |
FIQ (0 to 100) | ||||||||||
Baseline | 65.91 (10.85) | 66.36 (9.88) | 64.48 (10.50) | |||||||
Posttreatment | 46.21 (9.18) | 50.93 (9.38) | 48.64 (6.77) | 6.96 | 0.001 | 0.08 | 1 < 2, 3 | 0.51 | 0.30 | 0.28 |
Six-month follow-up | 48.80 (9.11) | 52.84 (9.17) | 53.26 (7.54) | 11.22 | 0.001 | 0.12 | 1 < 2, 3 | 0.44 | 0.53 | 0.05 |
EuroQol VAS (0 to 100) | ||||||||||
Baseline | 44.55 (16.47) | 46.82 (15.62) | 43.87 (14.50) | |||||||
Posttreatment | 60.45 (16.63) | 58.00 (13.07) | 53.49 (14.40) | 11.49 | 0.001 | 0.13 | 1 > 2, 3 | 0.16 | 0.45 | 0.33 |
Six-month follow-up | 58.39 (16.27) | 56.73 (13.85) | 52.26 (14.03) | 10.44 | 0.001 | 0.12 | 1 > 2, 3 | 0.11 | 0.40 | 0.32 |