Illness perceptions as a marker for accelerated disease progression during pre-dialysis care

Abstract

Background: Illness perceptions are associated with mortality in renal patients. However, no data is available regarding the relationship between illness perceptions and accelerated disease progression. Methods: 416 incident pre-dialysis patients participating in a prospective cohort (PREPARE-2) completed the Revised Illness Perception Questionnaire. Associations between illness perceptions, time until start of dialysis and change of kidney function (i.e. eGFR) over time, were investigated using Cox regression models and linear mixed modeling. Findings: After adjustment for sociodemographic and clinical variables, dialysis started earlier and kidney function declined faster (ml/min/1.73m2/year) in patients with an increased belief that their disease is cyclical (HR=1.32 [95%CI 1.11;1.56]; additional change -0.64 [95%CI -1.16;-0.13]), has negative consequences (HR=1.47 [95%CI 1.18;1.85]; additional change -0.67 [95%CI -1.30;-0.04]) and causes negative feelings (HR=1.21 [95%CI 1.03;1.42]; additional change -0.65 [95%CI -1.13;-0.16]). Furthermore, kidney function declined faster in patients with an increased belief that their disease cannot be personally controlled (additional change -0.69 [95%CI -1.31;-0.09]) and understood their disease less well (additional change -0.53 [95%CI -1.05;-0.01]). Discussion: Negative illness perceptions at the start of pre-dialysis care are a marker for accelerated disease progression.