Understanding eligibility creep in psoriasis assessments: a survey study

Psoriasis severity assessments for clinical trial entry may be unintentionally overestimated, especially if trial eligibility is chiefly dependent on rating of disease severity. When this results in patients with less severe phenotypes joining clinical trials it is referred to as eligibility creep. We investigated the potential impact of psychosocial incentives on psoriasis lesion severity grading. A survey was constructed and disseminated through Amazon Mechanical Turk. Participants completed two vignette-style questions prompted with a randomly allocated psychosocial incentive. Questions required participants to grade and select psoriasis lesion pictures for a fictional trial. Participants also decided whether or not to schedule re-evaluation of patients deemed ineligible at initial visit. There were 646 participants. There was no significant difference in number of total lesions selected for study inclusion between incentive groups (Kruskal-Wallis, P=0.30). In general, participants completing empathy and professional uncertainty incentives selected the most and least number of lesion pictures for trial inclusion, respectively. Participants prompted with empathy incentives had significantly greater rates of choosing to schedule a follow-up visit for ineligible patients compared to participants prompted with other incentives (69.7% versus 59.1%, Chi square P=0.046). Situations evoking empathy may contribute to eligibility creep.