Table 3 Comparison of population characteristics of included RCTs and observational cohort studies
| Cohort studies | RCTsa | ||
|---|---|---|---|
| Publication year | 1994-2012 | 1993-2012 | |
| Sample size, Median (range) | 368 (60, 2872) | 128 (28, 681)b | |
| 67 (12, 340)c | |||
| Age, mean d (SD) | 43 (4.1) | 44 (7.9) | |
| Female, mean percentage (SD) | 52 (4.8) | 53 (16.9) | |
| Type of pain, n (%) | Acute | 5 (26) | 34 (20) |
| Chronic | 2(11) | 94 (57) | |
| Mixed | 12(63) | 31 (19) | |
| Unclear | 0 | 6 (4) | |
| Baseline pain intensity, mean d (SD) | 49.6 (12.7) | 49.9 (12.9) |