Cost-effectiveness of cryotherapy versus salicylic acid for the treatment of plantar warts: economic evaluation alongside a randomised controlled trial (EVerT trial)

A cost-effectiveness analysis was undertaken alongside a pragmatic multicentre, randomised controlled trial assessing the clinical effectiveness of 50% salicylic acid and cryotherapy using liquid nitrogen at 12 weeks after randomisation of patients. Cost-effectiveness outcomes were expressed as the additional cost required to completely cure the plantar warts of one additional patient. A NHS perspective was taken for the analysis.Cryotherapy costs on average ￡101.17 (bias corrected and accelerated (BCA) 95% CI: 85.09-117.26) more per participant over the 12 week time-frame, while there is no additional benefit, in terms of proportion of patients healed compared with salicylic acid.Cryotherapy is more costly and no more effective than salicylic acid.Current Controlled Trials ISRCTN18994246 [controlled-trials.com] and National Research Register N0484189151.Plantar warts (verrucae) are extremely common, and are experienced by most people at some time during their lives [1,2]. Many will spontaneously disappear without treatment [3]. However, treatment may be sought for a variety of reasons, such as discomfort or being prevented from undertaking sports or activities of daily living. There are a number of different treatments for plantar warts. In the UK the first line of treatment is generally an over-the-counter (OTC) salicylic acid preparation at strength of 15-26%. Second line treatments include cryotherapy treatment using liquid nitrogen and higher concentrations of salicylic acid for example 50% salicylic acid. Other treatments such as surgical curettage, complementary and alternative therapies are also available; however, there is a very little evidence to support the use of any of these treatments [4]. Even after treatment some plantar warts may fail to resolve, or may resolve and then reappear. Reported recurrence rates of cutaneous warts vary between 19% [5] following treatment with cryotherapy to around 30% [4] following surgical removal.The treatment of warts