Proportion of patients with no pain relief for injection treatment v placebo in benign chronic low back pain*
| Comparisons | Length of follow up | Number of studies | Number of patients | Weighted event rates | RRR (95% CI) | NNT (CI) |
|---|---|---|---|---|---|---|
| *NS = not significant. Other abbreviations defined in glossary; RRR, NNT, and CI calculated from data in article. | ||||||
| †Event rates not weighted. | ||||||
| ‡1 negative study that did not publish raw data was excluded from this group. | ||||||
| <6 weeks | 1 | 97 | 59% v 67%† | 11% (−21 to 35) | NS | |
| Facet injection v placebo | >6 weeks | 1 | 97 | 65% v 73%† | 10% (−17 to 31) | NS |
| <6 weeks | 4 | 302 | 60% v 66% | 8% (−8 to 22) | NS | |
| Epidural injection v placebo | >6 weeks | 3 | 254 | 50% v 53% | 7% (−16 to 25) | NS |
| <6 weeks | 3‡ | 121 | 42% v 57% | 20% (−59 to 60) | NS | |
| Local injection v placebo | >6 weeks | 1 | 81 | 75% v 95%† | 21% (4 to 35) | 5 (3 to 20) |