Abstract
BACKGROUND AND OBJECTIVES: Many individuals with kidney disease, particularly those belonging to racial and ethnic minority groups and whose primary language is not English, lack knowledge related to kidney disease symptoms, physiologic functions of the kidney, and benefits and risks of kidney transplantation. Valid instruments to assess patients' knowledge of CKD and kidney transplantation are needed. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using a sample of 977 patients with stages 3-5 CKD in the Kaiser Permanente health system, we developed the Knowledge Assessment of Renal Transplantation (KART) 2.0 instrument. We conducted cognitive interviews followed by item response theory (IRT) to reduce 48 candidate items. Construct validity was tested by examining differences in scores between patients who spent <1 and ≥1 hour receiving CKD and transplant education. RESULTS: Cognitive interviews modified four items and omitted 11. IRT analyses resulted in two scales: the KART 2.0-Transplant Knowledge Scale (16 items; Cronbach's α=0.8) and the KART 2.0-CKD Knowledge Scale (nine items; Cronbach's α=0.79). Differential item functioning showed that the scales were unbiased to capture knowledge across self-identified race, primary language, CKD stage, and sex. Both scales distinguished patients who had spent <1 and ≥1 hour speaking with health professionals (effect size [ES]=0.33 [transplant], 0.54 [CKD]; P<0.001 for both), reading about kidney disease (ES=0.45 [transplant], 0.62 [CKD]; P<0.001), reading about kidney transplantation (ES=0.67 [transplant], 0.69 [CKD]; P<0.001), and reading about living donor kidney transplant (ES=0.76 [transplant], 0.62 [CKD]; P<0.001). CONCLUSIONS: The KART 2.0 is a valid tool to assess patients' knowledge of CKD and kidney transplantation.