A network analysis of the Brief Illness Perception Questionnaire in patients with rheumatic diseases and human immunodeficiency virus infection.

To examine the construct of illness perception (IP) as measured by the Brief Illness Perception Questionnaire (BIPQ) using network analysis in patients with rheumatic diseases (RD) and with human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS). Cross-sectional and multicentre survey. The BIPQ and the Hospital Anxiety and Depression Scale. BIPQ network structures did not differ between patients with RD and HIV/AIDS. Community analysis identified two clusters: one comprised consequences, timeline, identity, concern and emotional response; and the other consisted of personal control, treatment control and comprehensibility. Centrality indices indicate that concern, consequences and emotional response are central dimensions of the BIPQ. Directed acyclic graph analysis revealed that concern was a dominant network item, activating emotional response, consequences, identity and comprehensibility. Emotional response and consequences were bridging items linking IP to anxiety and depression. Perceived impact of illness on life and emotion and illness concern are central dimensions of the BIPQ that link IP to anxiety and depression in patients with RD and HIV/AIDS. Care of patients with RD and HIV/AIDS may benefit from addressing IP, particularly concern, emotional response and consequences to prevent clinical anxiety and depression.