Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Neurological disability
Systematic review	66 adults with cervical dystonia, see further information on studies Data from 1 RCT	Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-Disability score 12 weeks with botulinum A toxin (Dysport, 292 U in first session, 262 U in second session, under EMG guidance) plus placebo tablets with trihexyphenidyl (mean dose 16.25 mg) plus placebo injection Absolute results not reported	WMD 2.50 95% CI 0.68 to 4.32 P = 0.0097	Effect size not calculated	botulinum A toxin
Systematic review	66 adults with cervical dystonia, see further information on studies Data from 1 RCT	Tsui score 12 weeks with botulinum A toxin (Dysport, 292 U in first session, 262 U in second session, under EMG guidance) plus placebo tablets with trihexyphenidyl (mean dose 16.25 mg) plus placebo injection Absolute results not reported	WMD 4.60 95% CI 2.14 to 7.06 P = 0.0009	Effect size not calculated	botulinum A toxin
Systematic review	66 adults with cervical dystonia, see further information on studies Data from 1 RCT	Mean difference in General Health Perception subscale score with botulinum A toxin (Dysport, 292 U in first session, 262 U in second session, under EMG guidance) plus placebo tablets with trihexyphenidyl (mean dose 16.25 mg) plus placebo injection Absolute results not reported	Mean score difference 6 95% CI 4 to 12 P = 0.0023	Effect size not calculated	botulinum A toxin
Systematic review	66 adults with cervical dystonia, see further information on studies Data from 1 RCT	Proportion of people with at least 3-point improvement on Tsui scale with botulinum A toxin (Dysport, 292 U in first session, 262 U in second session, under EMG guidance) plus placebo tablets with trihexyphenidyl (mean dose 16.25 mg) plus placebo injection Absolute results not reported	OR 3.92 95% CI 1.48 to 10.40	Moderate effect size	botulinum A toxin
Systematic review	66 adults with cervical dystonia, see further information on studies Data from 1 RCT	Proportion of people with at least 3-point improvement on TWSTRS scale with botulinum A toxin (Dysport, 292 U in first session, 262 U in second session, under EMG guidance) plus placebo tablets with trihexyphenidyl (mean dose 16.25 mg) plus placebo injection Absolute results not reported	OR 3.14 95% CI 1.10 to 8.97 P = 0.059	Moderate effect size	botulinum A toxin
Systematic review	66 adults with cervical dystonia, see further information on studies Data from 1 RCT	Median improvement in TWSTRS-Pain score 3 with botulinum A toxin (Dysport, 292 U in first session, 262 U in second session, under EMG guidance) plus placebo tablets 1 with trihexyphenidyl (mean dose 16.25 mg) plus placebo injection	Reported this difference did not reach statistical significance, no further details reported		Not significant