Background/Purpose: Patients vary in their beliefs related to the cause of serious illness. The impact of these beliefs among patients with systemic vasculitis is not known. This study aimed to describe patient beliefs related to the cause of systemic vasculitis and to examine whether casual beliefs are associated with psychological impact of disease and functional impairment.

Methods: Participants were recruited online from a patient contact registry in vasculitis. Causal beliefs were measured using two approaches. Using an open-ended question, participants were asked to list the three most important causal beliefs about disease-onset. Responses were categorized and weighted by rank to determine the relative frequency of beliefs. Participants also rated 18 specified causal beliefs (obtained from the well-validated revised Illness Perception Questionnaire, IPQ-R) on a 5-point scale, with higher scores indicating stronger agreement. Response scores to the specified items were summed into a belief score which defined strength of causal beliefs. Psychological impact was measured using a scale from the IPQ-R assessing the negative emotional impact of vasculitis. The Medical Outcomes Study General Health Survey was used to assess functional impairment (physical, role, and social). Pearson correlation coefficients were calculated between belief scores, psychological, and functional impairment.

Results: 692 participants with 9 forms of vasculitis were included. There was considerable variability of causal beliefs among participants and beliefs differed by type of vasculitis (Table). The most common beliefs listed by participants using the open-ended approach were environmental exposures (16%), stress (15%), hereditary factors (15%), and infection (15%). For the 18 specified items (scored 1-5), altered immunity (3.6 ±1.1) and stress (3.2 ±1.3) were the most agreed upon causal items for each type of vasculitis. Negative emotional impact of illness, role, and social function were significantly correlated with belief score (r= 0.26, 0.12, 0.12; p<0.01). Physical function was not significantly associated with belief score (r=0.07, p=0.09).

Conclusion: Patient beliefs related to the cause of systemic vasculitis are highly variable. Patients with strongly-held causal beliefs report that their illness has greater negative impact on their psychological well-being and their ability to perform role and social functions. Clinicians who care for patients with vasculitis should be mindful of these associations and consider asking patients about their causal beliefs.