title: Treatment failure of patients using topical acne treatments: an observational retrospective cohort study.
abstract: BACKGROUND
  While limited data from clinical trials show differences in efficacy between topical acne combination products and monotherapies, the impact in clinical practice is not explored.
  
  
  OBJECTIVE
  To evaluate the effectiveness in clinical practice of prescribing topical acne combination treatments compared to monotherapy product(s) in minimizing treatment failures.
  
  
  METHODS
  Patients diagnosed with acne (ICD-9: 706.1) by a dermatologist between January 2009 and September 2011 and initially prescribed a topical acne treatment were identified. Multivariate Cox proportional hazards models were employed to compare the hazards of treatment failure for patients initially prescribed a combination product versus one monotherapy or multiple monotherapies. Subgroup analyses were also performed.
  
  
  RESULTS
  Three hundred and thirty-five patients were initially prescribed topical product(s) exclusively. The hazards of treatment failure for those prescribed a combination product compared to those prescribed one monotherapy product was HR = 0.91 (p = 0.65) and compared to those prescribed multiple monotherapy products was HR = 0.73 (p = 0.17).
  
  
  CONCLUSIONS
  Disease severity and treatments prescribed outside of the hospital system were not available.
  
  
  CONCLUSIONS
  Treatment failures were consistent for patients prescribed combination product(s) or monotherapies.
authors.affiliation: Center for Dermatology Research, Department of Dermatology, Wake Forest School of Medicine , Winston-Salem, North Carolina , USA.
authors.forename: Samuel Evan
authors.initials: SE
authors.lastname: Carstensen
authors.forename: Karen E
authors.initials: KE
authors.lastname: Huang
authors.forename: Steven R
authors.initials: SR
authors.lastname: Feldman
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult; D000152:Acne Vulgaris / Q000188:drug therapy; D000284:Administration, Oral; D000287:Administration, Topical; D015331:Cohort Studies; D003879:Dermatologic Agents / Q000008:administration & dosage; D004338:Drug Combinations; D004359:Drug Therapy, Combination; D012189:Retrospective Studies; D017211:Treatment Failure; D064887:Observational Studies as Topic
chemical_list: D003879:Dermatologic Agents; D004338:Drug Combinations