Table 2.
Summary of findings and certainty of evidence for low back pain in association with muscle relaxants
| Summary of findings | Certainty of evidence | Overall certainty of evidence | ||||||
|---|---|---|---|---|---|---|---|---|
| No of participants (No of trials) | Mean difference (95% CI), 0-100 | Risk of bias | Inconsistency | Imprecision | Publication bias | |||
| Acute low back pain | ||||||||
| Non-benzodiazepine antispasmodics: | ||||||||
| ≤2 weeks | 4546 (16) | −7.7 (−12.1 to −3.3) | Downgraded* | Downgraded† | Downgraded‡ | Not downgraded | Very low | |
| 3-13 weeks | 612 (3) | 0.6 (−4.5 to 5.7) | Not downgraded | Not downgraded | Downgraded‡ | Not downgraded | Moderate | |
| Antispastics: | ||||||||
| ≤2 weeks | 103 (1) | −1.6 (−15.3 to 12.1) | Not downgraded | Not downgraded¶ | Downgraded§e | Not downgraded¶ | Low | |
| 3-13 weeks | 99 (1) | 4.0 (−7.7 to 15.7) | Not downgraded | Not downgraded¶ | Downgraded‡ | Not downgraded¶ | Moderate | |
| Benzodiazepines: | ||||||||
| ≤2 weeks | 112 (1) | 2.0 (−9.8 to 13.8) | Not downgraded | Not downgraded¶ | Downgraded‡ | Not downgraded¶ | Moderate | |
| 3-13 weeks | 103 (1) | −1.0 (−10.4 to 8.4) | Not downgraded | Not downgraded¶ | Downgraded§ | Not downgraded¶ | Low | |
| Subacute low back pain | ||||||||
| Miscellaneous: | ||||||||
| 3-13 weeks | 28 (1) | −19.0 (−41.9 to 3.9) | Downgraded* | Not downgraded¶ | Downgraded§ | Not downgraded¶ | Very low | |
| Chronic low back pain | ||||||||
| Antispastics: | ||||||||
| 3-13 weeks | 80 (1) | −5.4 (−13.7 to 2.9) | Downgraded* | Not downgraded | Downgraded§ | Not downgraded¶ | Very low | |
| Miscellaneous: | ||||||||
| 3-13 weeks | 52 (1) | −19.9 (−31.5 to −8.3) | Not downgraded | Not downgraded¶ | Downgraded‡ | Not downgraded¶ | Moderate | |
| Mixed low back pain | ||||||||
| Non-benzodiazepine antispasmodics: | ||||||||
| ≤2 weeks | 617 (2) | −4.4 (−6.9 to −1.9) | Downgraded* | Not downgraded | Not downgraded | Not downgraded | Low | |
| 3-13 weeks | 329 (1) | −5.8 (−13.8 to 2.2) | Downgraded* | Not downgraded¶ | Downgraded§ | Not downgraded¶ | Very low | |
Data are mean differences for pain intensity on a 0 to 100 scale. Negative values for mean differences indicate that effects favour muscle relaxant medicines compared to control.
*
Downgraded two levels: >50% of participants were from studies at high risk of bias.
†
Downgraded one level: heterogeneity (I2) was >50%.
‡
Downgraded one level: limits of the 95% confidence interval crossed the minimally clinically important difference or the null.
§
Downgraded two levels: limits of the 95% confidence interval crossed the minimally clinically important difference and the null.
¶
Not downgraded: could not be determined with one study.