Patients,’ Nephrologists,’ and Predicted Estimations of ESKD Risk Compared with 2-Year Incidence of ESKD

Abstract

Visual Abstract

Background and objectives 

The rate of progression to ESKD is variable, and prognostic information helps patients and physicians plan for future ESKD. We assessed the estimations of ESKD risk of patients with CKD and physicians and compared them with risk calculators and outcomes at 2 years.

Design, setting, participants, & measurements 

This prospective observational study assessed 257 adult patients with CKD stages 3–5 and their nephrologists at University of California, San Diego and Veterans Affairs San Diego CKD clinics. Patients’ and nephrologists’ estimations of 2-year ESKD risk were evaluated, and objective estimation of 2-year risk was determined using kidney failure risk equations; actual incidence rates of ESKD and death were ascertained by chart review. Participants’ baseline characteristics were compared across kidney failure risk equation risk levels and according to whether patients’ estimations were more optimistic or pessimistic than physicians’ estimations. We examined correlations between estimations and compared estimations with outcomes using c statistics and calibration plots.

Results 

Average age was 65 (±13) years old, and eGFR was 34 (±13) ml/min per 1.73 m². Overall, 13% reached ESKD, and 9% died. About one quarter of patients gave estimates that were >20% more optimistic than physicians, and more than one in ten gave estimates that were >20% more pessimistic. Physicians’ and kidney failure risk equation estimations had the strongest correlation (r=0.72; P<0.001) compared with 0.50 (P<0.001) between physicians and patients and 0.47 (P<0.001) between patients and kidney failure risk equation. Although all three estimations provided reasonable risk rankings (c statistics >0.8), physicians and patients overestimated risk compared with actual outcomes; no patient whose physician estimated a risk of ESKD <15% reached ESKD at 2 years. The kidney failure risk equation was best calibrated to actual ESKD risk.

Conclusions 

Compared with actual ESKD incidence, the kidney failure risk equation outperformed patients’ and physicians’ estimations of ESKD incidence. Patients and physicians overestimated risk compared with the kidney failure risk equation.