Eliciting preferences to inform patient-centred policies: the case of psoriasis

To assess patient preferences for psoriasis treatment features and to investigate the heterogeneity of preferences among patients with different socio-demographic and disease-related characteristics.

A discrete choice experiment was conducted on adult patients with moderate to severe plaque-type psoriasis during a routine visit to their physician at 15 centres in Italy. We investigated the preferences of patients with respect to five treatment attributes: (1) mode and frequency of administration; (2) time to improvement; (3) time free of symptoms; (4) unintended life expectancy reduction resulting from treatment; and (5) monthly treatment cost. The heterogeneity of preferences was investigated in a mixed logit model with normally distributed random coefficients.

Overall, patients preferred the subcutaneous or intravenous route of administration (versus oral administration) and treatments that took less time to show improvement, ensured a longer time free of symptoms, involved a lesser reduction in life expectancy and had lower costs. There was significant preference heterogeneity for all attributes. The cost attribute was found to be significantly more important to females and to older patients (above 60 years of age). Older patients placed significantly greater emphasis on reduced life expectancy, whereas the time free of symptoms was significantly less important to them than to patients under 60 years of age. Patients with higher scores on the Dermatology Life Quality Index (DLQI) placed higher value on the time free of symptoms than those with lower DLQI scores. For the overall sample, the marginal willingness to pay (WTP) for a month's reduction in the time to improvement was 32.4, whereas the WTP for one additional month without symptoms was significantly higher (68.2).

Patient-centred policies should consider the heterogeneity of patients' expectations to identify individualized treatments that would aid in optimizing patient satisfaction and wellbeing, as well as overall treatment effectiveness.