Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Adverse effects
RCT	139 adults who previously responded to botulinum A toxin	Dysphagia 4 weeks 19% with botulinum A toxin 48% with botulinum B toxin Absolute numbers not reported	P = 0.0005	Effect size not calculated	botulinum A toxin
RCT	139 adults who previously responded to botulinum A toxin	Dry mouth 4 weeks 41% with botulinum A toxin 80% with botulinum B toxin Absolute numbers not reported	P <0.0001	Effect size not calculated	botulinum A toxin
RCT	20 adults who responded to botulinum A toxin within the previous year	Dysphagia 18% with botulinum A toxin 55% with botulinum B toxin Absolute numbers not reported	P = 0.081		Not significant
RCT	20 adults who responded to botulinum A toxin within the previous year	Constipation 0/11 (0%) with botulinum A toxin 3/9 (33%) with botulinum B toxin	P = 0.037	Effect size not calculated	placebo
RCT	111 adults, not previously treated with botulinum toxin (toxin naive)	Dysphagia 8/55 (15%) with botulinum A toxin 9/56 (16%) with botulinum B toxin	P = 1		Not significant
RCT	111 adults with cervical dystonia, not previously treated with botulinum toxin (toxin naive)	Dry mouth 4/55 (7%) with botulinum A toxin 22/56 (39%) with botulinum B toxin	P = 0.0001	Effect size not calculated	botulinum A toxin
RCT	111 adults with cervical dystonia, not previously treated with botulinum toxin (toxin naive)	Injection site pain 3/55 (5%) with botulinum A toxin 0/56 (0%) with botulinum B toxin	P = 0.12		Not significant