Summary of findings for the main comparison. Corticosteroids compared to placebo or no treatment for Bell's palsy.
| Corticosteroids compared to placebo or no treatment for Bell's palsy | ||||||
| Patient or population: people with Bell's palsy Settings: primary and secondary care Intervention: corticosteroids Comparison: placebo or no treatment | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Placebo or no treatment | Corticosteroids | |||||
| Incomplete recovery ≥ 6 months after randomisation House‐Brackmann grading system and Sunnybrook scale Follow‐up: 157 days to 12 months | 281 per 1000 | 177 per 1000 (140 to 225) | RR 0.63 (0.50 to 0.80) | 895 (7 studies) | ⊕⊕⊕⊕ high1 | NNTB 10, 95% CI 6 to 20 |
| Cosmetically disabling persistent sequelae ≥ 6 months after randomisation Clinical assessment Follow‐up: mean 6 months | 216 per 1000 | 208 per 1000 (86 to 495) | RR 0.96 (0.4 to 2.29) | 75 (2 studies) | ⊕⊕⊝⊝ low2,3 | ‐ |
| Motor synkinesis and crocodile tears Clinical assessment Follow‐up: 9 to 12 months | 260 per 1000 | 167 per 1000 (117 to 237) | RR 0.64 (0.45 to 0.91) | 485 (3 studies) | ⊕⊕⊕⊝ moderate4 | ‐ |
| Adverse effects Follow‐up: 9 to 12 months | 127 per 1000 |
133 per 1000 (91 to 192) |
RR 1.04 (0.71 to 1.51) | 715 (3 studies) | ⊕⊕⊕⊝ moderate5 | 3 other studies recorded that no adverse effects occurred with corticosteroid treatment |
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; NNTB: number needed to treat for an additional beneficial outcome; RR: risk ratio. | ||||||
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
1 Two trials excluded participants who were found to have clinical evidence of herpes zoster infection (Lagalla 2002; Taverner 1954). In addition, two studies did not use a scoring system such as the House‐Brackmann or Sunnybrook scale to assess facial motor function, relying upon clinical examination, electromyographic tests or photographs (May 1976; Taverner 1954). Taverner 1954 reported outcomes at five months rather than at six months or more. However, we felt that these limitations did not compromise the generalisability of the findings.
2 We downgraded twice: first for imprecision ‐ there was a low number of events and pooled RR allowed the possibility of both no effect and the chance of harm; second for publication bias ‐ of the seven included studies, five did not provide data on the presence of cosmetically disabling sequelae six months or more after randomisation.
3 We downgraded once for imprecision. There was a low number of events.
4 We downgraded the quality of the evidence to moderate because of publication bias.
5 We downgraded for publication bias ‐ only three of seven studies provided data on adverse effects.