title: OnabotulinumtoxinA: a meta-analysis of duration of effect in the treatment of glabellar lines.
abstract: BACKGROUND
  Duration of effect of aesthetic treatments with botulinum toxin potentially influences subject satisfaction, treatment frequency, and annual costs, but quantitative outcomes for measuring duration of effect and correlations with subject satisfaction have yet to be fully elucidated.
  
  
  METHODS
  Phase III clinical trials with similar designs were identified and their data pooled to ascertain duration of clinical effect of onabotulinumtoxinA in glabellar muscles. Duration was calculated using the Kaplan-Meier method for investigator-rated Facial Wrinkle scale (FWS) scores and subject global assessment (SGA) of glabellar lines. Responders were determined according to FWS score at maximum contraction and at repose 30 days after injection.
  
  
  RESULTS
  Data from four trials with 621 onabotulinumtoxinA-treated (20 U) subjects were analyzed, 523 of these (84.2%) were identified as day-30 responders on the FWS at maximum contraction. Pooled median duration of effect for day-30 responders was 120 days for FWS at maximum contraction and 131 days for FWS at repose. Higher day 30 SGA scores were correlated with a greater duration of effect on dynamic, but not static lines.
  
  
  CONCLUSIONS
  Treatment of glabellar lines with 20 U of onabotulinumtoxinA resulted in sustained clinical benefit for 4 months in more than 50% of responders; subject satisfaction increased with duration of effect.
authors.affiliation: Department of Dermatology, University of California at San Francisco, CA, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Glogau
authors.forename: Michael
authors.initials: M
authors.lastname: Kane
authors.forename: Frederick
authors.initials: F
authors.lastname: Beddingfield
authors.forename: Christine
authors.initials: C
authors.lastname: Somogyi
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Lei
authors.forename: Carrie
authors.initials: C
authors.lastname: Caulkins
authors.forename: Conor
authors.initials: C
authors.lastname: Gallagher
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D017326:Clinical Trials, Phase III as Topic; D003357:Cosmetic Techniques; D005260:Female; D005546:Forehead; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects; D017060:Patient Satisfaction; D016032:Randomized Controlled Trials as Topic; D015595:Skin Aging; D013997:Time Factors
chemical_list: D019274:Botulinum Toxins, Type A