title: Evaluating clinical trial design: systematic review of randomized vehicle-controlled trials for determining efficacy of benzoyl peroxide topical therapy for acne.
abstract: Determined efficacies of benzoyl peroxide may be affected by study design, implementation, and vehicle effects. We sought to elucidate areas that may allow improvement in determining accurate treatment efficacies by determining rates of active treatment and vehicle responders in randomized controlled trials assessing the efficacy of topical benzoyl peroxide to treat acne. We conducted a systematic review of randomized vehicle-controlled trials evaluating the efficacy of topical benzoyl peroxide for the treatment of acne. We compared response rates of vehicle treatment arms versus those in benzoyl peroxide arms. Twelve trials met inclusion criteria with 2818 patients receiving benzoyl peroxide monotherapy treatment and 2004 receiving vehicle treatment. The average percent reduction in total number of acne lesions was 44.3 (SD = 9.2) and 27.8 (SD = 21.0) for the active and vehicle treatment groups, respectively. The average reduction in non-inflammatory lesions was 41.5 % (SD = 9.4) in the active treatment group and 27.0 % (SD = 20.9) in the vehicle group. The average percent decrease in inflammatory lesions was 52.1 (SD = 10.4) in the benzoyl peroxide group and 34.7 (SD = 22.7) in the vehicle group. The average percentage of participants achieving success per designated study outcomes was 28.6 (SD = 17.3) and 15.2 (SD = 9.5) in the active treatment and vehicle groups, respectively. Patient responses in randomized controlled trials evaluating topical acne therapies may be affected by clinical trial design, implementation, the biologic effects of vehicles, and natural disease progression. "No treatment" groups may facilitate determination of accurate treatment efficacies.
authors.affiliation: Department of Dermatology, New York Medical College, Metropolitan Hospital Center, New York, NY, USA.
authors.forename: Sonia A
authors.initials: SA
authors.lastname: Lamel
authors.affiliation: Department of Dermatology, University of California, Davis School of Medicine, Sacramento, USA.
authors.forename: Raja K
authors.initials: RK
authors.lastname: Sivamani
authors.affiliation: Department of Pathology, Loma Linda University, School of Medicine, Loma Linda, USA.
authors.forename: Maral
authors.initials: M
authors.lastname: Rahvar
authors.affiliation: Department of Dermatology, University of California, San Francisco School of Medicine, 90 Medical Center Way Surge 110, Box 0989, San Francisco, CA, 94143, USA. maibachh@derm.ucsf.edu.
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
mesh_terms: D000152:Acne Vulgaris / Q000188:drug therapy*; D000287:Administration, Topical; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001585:Benzoyl Peroxide / Q000627:therapeutic use*; D003879:Dermatologic Agents / Q000627:therapeutic use*; D005782:Gels / Q000627:therapeutic use; D006801:Humans; D015990:Placebo Effect; D011425:Propionibacterium acnes / Q000187:drug effects; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D012107:Research Design; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D003879:Dermatologic Agents; D005782:Gels; D001585:Benzoyl Peroxide
keywords: Acne; Benzoyl peroxide; Placebo effect; Placebo response; Randomized controlled trial; Study design; Topical administration; Vehicle delivery