Table 3.

Summary of findings comparing intramuscular botulinum toxin to placebo in patients with shoulder spasticity.

OutcomesIllustrative Comparative Risks* (95% CI)Relative Effect (95% CI)No. Participants (studies)Quality of Evidence (GRADE)Comments
Assumed Risk ControlCorresponding Risk Intramuscular Botulinum toxin
Pain (0–10 cm VAS or 0–10 VRS at 12–24 wksMean pain (0–10 cm VAS): pain at 6–12 wks in control groups was 4.8Mean pain (0–10 cm VAS): pain at 6–12 wks in intervention groups was 1.22 lower (0.07 to 2.37 lower)NA76 (3)+ + − −
Low1,2
Absolute risk difference 12% (95% CI 1% to 24%); relative percentage change 25% (95% CI 1% to 49%); NNT benefit = 4 (95% CI 2 to 102)
No. adverse events (followup 4–24 wks)235 per 1000343 per 1000 (150 to 790)RR 1.46 (0.64 to 3.36)65 (3)+ + − −
Low1,2
Absolute risk difference 9% (95% CI −22% to 39%); relative percentage change 46% (95% CI −36% to 226%); NNT harm = not estimable3
Disability/functionNot reported in any studyNot reported in any studyNot estimableNANA
Withdrawals due to adverse eventsNot reported in any studyNot reported in any studyNot estimableNANA
Serious adverse eventsNot reported in any studyNot reported in any studyNot estimableNANA
  • * The basis for the assumed risk (e.g., the median control group risk across studies) is provided in footnotes. The corresponding risk (95% is based on the assumed risk in the comparison group and the relative effect of the intervention (95% CI).

  • 1 Allocation sequence generation and allocation concealment was not described in some studies.

  • 2 Sample sizes were small for all studies, making estimates liable to error.

  • 3 95% CI includes both positive and negative numbers, therefore NNT harm is not estimable.

  • 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 influence on our confidence in the estimate of effect and may change the estimate. Low quality: further research is very likely to have an important influence 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. RR: risk ratio; NA: not applicable; VAS: visual analog scale; VRS: verbal rating scale; NNT: number needed to treat.