Table 3. Synergistic effects for the four different CBP/PD groups for GP visits.
| CBP | PD | GP consultations | Model I Crude | Model II a | Model III b |
|---|---|---|---|---|---|
| % (n) | OR (95% CI) | OR (95% CI) | OR (95% CI) | ||
| + | + | 55.9 (1,551) | 3.64 (3.32–4.00) | 2.67 (2.42–2.95) | 2.03 (1.83–2.25) |
| + | - | 42.9 (969) | 2.16 (1.96–2.39) | 1.74 (1.57–1.93) | 1.54 (1.39–1.72) |
| - | + | 36.2 (1,379) | 1.63 (1.50–1.78) | 1.53 (1.40–1.67) | 1.34 (1.22–1.47) |
| - | - | 25.8 (1,709) | 1.0 | 1.0 | 1.0 |
| S | 1.48 (1.26–1.73) | 1.32 (1.08–1.61) | 1.16 (0.90–1.51) | ||
| PAF | 0.23 (0.15–0.32) | 0.15 (0.05–0.25) | 0.07 (-0.05–0.19) | ||
| RERI | 0.85 (0.51–1.19) | 0.40 (0.12–0.68) | 0.14 (-0.10–0.39) |
aModel II: adjusted for socio-demographics (sex, age, education, country of origin, place of residence, living with partner)
bModel III: similar to model II with additional adjustment for each chronic somatic disease other than chronic pain of the vertebral column and psychological diseases surveyed, BMI, and recent smoking status
CBP: chronic back pain; GP: General Practitioner; PAF: population attributable fraction; PD: psychological distress; RERI: relative excess risk due to interaction; S: synergy index