Effectiveness and cost-effectiveness of salicylic acid and cryotherapy for cutaneous warts: an economic decision model

Thomas, K.S. and Keogh-Brown, M.R. and Chalmers, J.R. and Fordham, R.J. and Holland, R.C. and Armstrong, S.J. and Bachmann, M.O. and Howe, A.H. and Rodgers, S. and Avery, Anthony and Harvey, I. and Williams, H.C. (2006) Effectiveness and cost-effectiveness of salicylic acid and cryotherapy for cutaneous warts: an economic decision model. Project Report. NHS R&D HTA Programme, Health Technology Assesment.

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Objectives: To estimate the costs of commonly used

treatments for cutaneous warts, as well as their health

benefits and risk. To create an economic decision model

to evaluate the cost-effectiveness of these treatments,

and, as a result, assess whether a randomised controlled

trial (RCT) would be feasible and cost-effective.

Data sources: Focus groups, structured interviews

and observation of practice. Postal survey sent to 723

patients. A recently updated Cochrane systematic

review and published cost and prescribing data.

Review methods: Primary and secondary data

collection methods were used to inform the

development of an economic decision model. Data from

the postal survey provided estimates of the

effectiveness of wart treatments in a primary care

setting. These estimates were compared with outcomes

reported in the Cochrane review of wart treatment,

which were largely obtained from RCTs conducted in

secondary care. A decision model was developed

including a variety of over-the-counter (OTC) and GPprescribed

treatments. The model simulated 10,000

patients and adopted a societal perspective.

Results: OTC treatments were used by a substantial

number of patients (57%) before attending the GP

surgery. By far the most commonly used OTC

preparation was salicylic acid (SA). The results of the

economic model suggested that of the treatments

prescribed by a GP, the most cost-effective treatment

was SA, with an incremental cost-effectiveness ratio

(ICER) of 2.20 £/% cured. The ICERs for cryotherapy

varied widely (from 1.95 to 7.06 £/% cured) depending

on the frequency of applications and the mode of

delivery. The most cost-effective mode of delivery was

through nurse-led cryotherapy clinics (ICER =

1.95 £/% cured) and this could be a cost-effective

alternative to GP-prescribed SA. Overall, the OTC

therapies were the most cost-effective treatment

options. ICERs ranged from 0.22 £/% cured for OTC

duct tape and 0.76 £/% cured for OTC cryotherapy to

1.12 £/% cured for OTC SA. However, evidence in

support of OTC duct tape and OTC cryotherapy is

very limited. Side-effects were commonly reported for

both SA and cryotherapy, particularly a burning

sensation, pain and blistering.

Conclusions: Cryotherapy delivered by a doctor is an

expensive option for the treatment of warts in primary

care. Alternative options such as GP-prescribed SA and

nurse-led cryotherapy clinics provide more costeffective

alternatives, but are still expensive compared

with self-treatment. Given the minor nature of most

cutaneous warts, coupled with the fact that the

majority spontaneously resolve in time, it may be

concluded that a shift towards self-treatment is

warranted. Although both duct tape and OTC

cryotherapy appear promising new self-treatment

options from both a cost and an effectiveness

perspective, more research is required to confirm the

efficacy of these two methods of wart treatment. If

these treatments are shown to be as cost-effective as

or more cost-effective than conventional treatments,

then a shift in service delivery away from primary care

towards more OTC treatment is likely. A public

awareness campaign would be useful to educate

patients about the self-limiting nature of warts and the

possible alternative OTC treatment options available.

Two future RCTs are recommended for consideration:

a trial of SA compared with nurse-led cryotherapy in

primary care, and a trial of home treatments. Greater

understanding of the efficacy of these home treatments

will give doctors a wider choice of treatment options,

and may help to reduce the overall demand for

cryotherapy in primary care.

Item Type: Monograph (Project Report)
Additional Information: NIHR Health Technology Assessment programme: Executive Summaries, Vol 10 no 25.
Schools/Departments: University of Nottingham, UK > Faculty of Medicine and Health Sciences > School of Medicine
Depositing User: attreed, karen
Date Deposited: 20 Mar 2008 11:24
Last Modified: 12 Oct 2017 11:32
URI: http://eprints.nottingham.ac.uk/id/eprint/869

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