Table 4 Difference-in-difference estimators (ATT) and their respective standard errors (SE) for analysis of two subgroups with (1) minor impairment due to back pain (GCPS Grades I and II) and (2) major impairment due to back pain (GCPS Grades III and IV), respectively, at study enrolment
Minor impairment (1) | MBR (n =59) | Control (n=61) | DiD | |||
Item | Baseline | Follow-up | Baseline | Follow-up | ATTa | SE |
Total cost (€) | 14636 | 15749 | 11242 | 11761 | 594 | 3564 |
 Back pain-specific cost (€) | 2935 | 2143 | 2177 | 1956 | -571 | 701 |
 Inpatient cost – back pain (€) | 578 | 186 | 430 | 190 | -152 | 348 |
 Outpatient cost – back pain (€) | 2356 | 1957 | 1747 | 1766 | -419 | 566 |
Sick leave in last 6 months due to back painb | 3.3 | 5.8 | 3.3 | 15.3 | -9.5* | 2.91 |
Overall health status (EQ-5D)b | 0.699 | 0.749 | 0.699 | 0.710 | 0.039 | 0.02 |
Major impairment (2) | MBR (n=53) | Control (n=50) | DiD | |||
Item | Baseline | Follow-up | Baseline | Follow-up | ATTa | SE |
Total Cost (€) | 18850 | 13805 | 21442 | 18543 | -2146 | 4617 |
 Back pain-specific cost (€) | 4031 | 2296 | 3444 | 3533 | -1824* | 856 |
 Inpatient cost – back pain (€) | 1295 | 336 | 424 | 926 | -1462* | 600 |
 Outpatient cost – back pain (€) | 2736 | 1960 | 3021 | 2606 | -362 | 633 |
Sick leave in last 6 months due to back painb | 64 | 33.2 | 64 | 60.4 | -27.2** | 7 |
Overall health status (EQ-5D)b | 0.494 | 0.591 | 0.494 | 0.544 | 0.047 | 0.02 |