title: EVerT: cryotherapy versus salicylic acid for the treatment of verrucae--a randomised controlled trial.
abstract: OBJECTIVE
  To compare the clinical effectiveness and cost-effectiveness of cryotherapy using liquid nitrogen versus patient daily self-treatment with 50% salicylic acid for the treatment of verrucae (plantar warts).
  
  
  METHODS
  A multicentre, pragmatic, open, two-armed randomised controlled trial with an economic evaluation. Randomisation was simple, with the allocation sequence generated by a computer in a 1 : 1 ratio.
  
  
  METHODS
  Podiatry clinics, university podiatry schools and primary care in England, Scotland and Ireland.
  
  
  METHODS
  Patients were eligible if they presented with a verruca which, in the opinion of the health-care professional, was suitable for treatment with both salicylic acid and cryotherapy, and were aged 12 years and over.
  
  
  METHODS
  Cryotherapy using liquid nitrogen delivered by a health-care professional compared with daily patient self-treatment with 50% salicylic acid (Verrugon, William Ransom & Son Plc, Hitchin, UK) for a maximum of 8 weeks.
  
  
  METHODS
  The primary outcome was complete clearance of all verrucae at 12 weeks. Secondary outcomes were complete clearance of all verrucae at 12 weeks, controlling for age, whether or not the verrucae had been previously treated and type of verrucae, with a second model to explore the effect of patient preferences, time to clearance of verrucae, clearance of verrucae at 6 months, number of verrucae at 12 weeks and patient satisfaction with the treatment.
  
  
  RESULTS
  In total, 240 eligible patients were recruited, with 117 patients allocated to the cryotherapy group and 123 to the salicylic acid group. There was no evidence of a difference in clearance rates between the treatment groups in the primary outcome [17/119 (14.3%) in the salicylic acid group vs 15/110 (13.6%) in the cryotherapy group; p = 0.89]. The results of the study did not change when controlled for age, whether or not the verrucae had been previously treated and type of verrucae, or when patient preferences were explored. There was no evidence of a difference in time to clearance of verrucae between the two groups [hazard ratio (HR) 0.80, 95% confidence interval (CI) 0.51 to 1.25; p = 0.33] or in the clearance of verrucae at 6 months (33.7% cryotherapy vs 30.5% salicylic acid). There was no evidence of a difference in the number of verrucae at 12 weeks between the two groups (incidence rate ratio 1.08, 95% CI 0.81 to 1.43; p = 0.62). Nineteen participants reported 28 adverse events, 14 in each group, with two treatment-related non-serious adverse events in the cryotherapy group. Cryotherapy was also associated with higher mean costs per additional healed patient (£101.17, 95% bias-corrected and accelerated CI £85.09 to £117.26). The probability of cryotherapy being cost-effective is 40% for a range of willingness-to-pay thresholds of £15,000-30,000 per patient healed.
  
  
  CONCLUSIONS
  There is no evidence for a difference in terms of clearance of verrucae between cryotherapy and salicylic acid (at both 12 weeks and 6 months), number of verrucae at 12 weeks and time to clearance of verrucae. Cryotherapy was associated with higher mean costs per additional healed patient compared with salicylic acid.
  
  
  BACKGROUND
  Current Controlled Trials ISRCTN18994246.
  
  
  BACKGROUND
  This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 15, No. 32. See the HTA programme website for further project information.
authors: Department of Health Sciences, York Trials Unit, University of York, York, UK.
authors: S
authors: S
authors: Cockayne
authors: M
authors: M
authors: Curran
authors: G
authors: G
authors: Denby
authors: F
authors: F
authors: Hashmi
authors: C
authors: C
authors: Hewitt
authors: K
authors: K
authors: Hicks
authors: S
authors: S
authors: Jayakody
authors: A
authors: A
authors: Kang'ombe
authors: C
authors: C
authors: McIntosh
authors: N
authors: N
authors: McLarnon
authors: E
authors: E
authors: Stamuli
authors: K
authors: K
authors: Thomas
authors: G
authors: G
authors: Turner
authors: D
authors: D
authors: Torgerson
authors: I
authors: I
authors: Watt
mesh_terms: D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003362:Cost-Benefit Analysis; D017679:Cryotherapy / Q000191:economics / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020156:Salicylic Acid / Q000191:economics / Q000627:therapeutic use*; D016896:Treatment Outcome; D014860:Warts / Q000188:drug therapy* / Q000601:surgery*; D055815:Young Adult
chemical_list: D020156:Salicylic Acid