Reliability of self-reported willingness-to-pay and annual income in patients treated for toenail onychomycosis.

BACKGROUND: Willingness-to-pay (WTP) is a health economics measure that has recently been used for skin diseases to evaluate patients' quality of life. However, the reliability of this measure has not been investigated in the dermatology literature and is essential in validating its use in health services research. OBJECTIVES: This study evaluated the test-retest reliability of self-reported annual income and WTP, a health economics measure of disease impact, in patients with toenail onychomycosis. METHODS: Forty-six patients enrolled in a randomized clinical trial comparing two different dosing regimens of terbinafine completed a self-administered questionnaire at baseline and 1 month later. The questionnaire asked: (i) how much patients would be willing to pay for a theoretical treatment with a cure rate of 85% for their current onychomycosis (10 categories: $0-50, $51-100, to > $800); and (ii) annual income (10 categories: $0-10,000 to > $200,000). RESULTS: Forty-four patients reported WTP at both visits, and 55% reported the same WTP. The quadratic-weighted (Fleiss-Cohen) kappa statistic indicated moderate agreement (kappa = 0.50, 95% confidence interval, CI 0.24-0.75, P < 0.01) as did the Spearman rank-order correlation coefficient (r(s) = 0.57, P < 0.01; median difference = 0, P = 0.50). Strong agreement was shown among the 42 patients who reported income at both visits; 71% reported the same annual income category (kappa = 0.72, 95% CI 0.47-0.96, P < 0.01; r(s) = 0.68, P < 0.01; median difference = 0, P = 0.77). Age, disease severity and duration, previous therapy, self-reported annual income, and medication side-effects were not statistically associated with the reliability of WTP. CONCLUSIONS: WTP and annual income demonstrated moderate and strong test-retest reliability, respectively. Self-reported WTP can serve as a reliable measure for future health economics research on onychomycosis.

Congenital Volkmann ischaemic contracture: a case report and review.

Congenital Volkmann ischaemic contracture or neonatal compartment syndrome has rarely been discussed in the literature of dermatology. The condition often involves the upper extremity with cutaneous lesions, contractures and neuropathy. Because the lesions can be mistaken for other entities including necrotizing fasciitis, neonatal gangrene, congenital varicella, aplasia cutis congenita, amniotic band syndrome, subcutaneous fat necrosis and epidermolysis bullosa, dermatologists play a significant role in the diagnosis and, consequently, the treatment of the patient. We describe a premature newborn who had a unilateral, well-demarcated necrotic plaque with a central pallor at birth. The plaque extended circumferentially over the left forearm from the wrist to the elbow. Left wrist oedema, bullae over the fingers and flaccid paralysis at the wrist were also noted.