Psoriasis is a persistent skin disorder characterized by abnormal keratinocyte differentiation, keratinocyte hyperproliferation, and increased expression of inflammatory markers at the cellular level, leading to
erythema, induration, and scaling of the skin. Depending on the severity of the disease, annual outpatient costs range from $1400 to $6600 per patient, totaling $3.2 billion each year in the United States. Because the disease is persistent and progressive, patients receiving a diagnosis of
psoriasis early in life can expect to require lifelong care, which translates into lifelong expense. Treatments include topical formulations, systemic
therapies,
phototherapies, and combination
therapies. Of these, topical agents are the first-line treatments, including
fluocinonide and other
steroids,
calcipotriene, and
tazarotene, a once-daily
retinoid. To establish the relative cost-effectiveness of these drugs (
fluocinonide,
calcipotriene, and
tazarotene), we conducted a pharmacoeconomic study from the perspective of a third-party payer, using a decision-analytic model validated by clinical experts. Data were drawn from a meta-analysis of the contemporary medical literature. Clinical success, clearing, and relapse rates determined the probabilities for therapeutic outcomes and the number of anticipated disease-free days for each study comparator. Costs for physician visits,
drug acquisition, laboratory testing, and adverse-events management were added to each branch of the decision tree and multiplied by the appropriate probabilities to establish the expected cost of treatment, stratified by the primary treatment choice. Cost-effectiveness was expressed as the total expected cost of achieving a disease-free day.
Tazarotene 0.1% was 16.74% more cost-effective than
tazarotene 0.05%, 85.46% more cost-effective than
fluocinonide, and 143.75% more cost-effective than
calcipotriene. The expected cost of achieving a disease-free day was $49.46 for
tazarotene 0.1%, $57.74 for
tazarotene 0.05%, $91.73 for
fluocinonide, and $120.56 for
calcipotriene. Treatment with
tazarotene offers an opportunity to reduce the cost of care for patients with mild-to-moderate
psoriasis and enhance patient satisfaction by gaining more disease-free days.