Added value of screening for CKD among the elderly or persons with low socioeconomic status

Abstract

Background and objective: Three screening approaches were compared for their ability to detect CKD cases, and identify patients with CKD who have a higher rate of incident cardiovascular disease (CVD) events and renal function decline. Approach 1 was the traditional CKD screening approach, targeting only individuals with known diabetes, hypertension, or CVD history. Approach 2 was defined as Approach 1+elderly, and Approach 3 as Approach 1+low-socioeconomic status (SES) individuals.

Design, setting, participants, & measurements: Data on 3411 individuals from the general population in The Netherlands were examined. Individuals aged >60 years were classified as elderly. Persons with low SES was defined as those with primary school or below primary school education. CKD was diagnosed during outpatient clinic visits. Individuals were followed for 9.4±2.6 years during four screening rounds.

Results: At baseline, 16%, 29%, and 25% of the general population was to be screened and 36%, 59%, and 51% of the CKD (n=263) cases were detected in Approaches 1, 2, and 3, respectively. The numbers of individuals needed to screen to detect one CKD case were 5.6 in Approach 1 and 6.5 each in Approach 2 and 3. In Approach 2 the hazard ratio for incident CVD events was 1.87 (95% confidence interval [95% CI], 1.35 to 2.61) in detected and 1.92 (95% CI, 1.01 to 3.64) in undetected CKD cases compared with persons without CKD, whereas in Approach 3 these values were 2.31 (95% CI, 1.64 to 3.25) and 1.28 (95% CI, 0.77 to 2.13), respectively. In Approach 2, the rate of renal function decline was -1.37 ml/min per 1.73 m(2) per year in detected and -1.13 ml/min per 1.73 m(2) per year in undetected CKD cases. In Approach 3, these figures were -1.41 and -1.14 ml/min per 1.73 m(2) per year, respectively.

Conclusions: Adding persons with low SES, rather than adding elderly persons, to the traditional high-risk groups may help detect more persons with CKD who have a higher rate of future CVD events and renal function decline.

Keywords: CKD; cardiovascular disease; epidemiology and outcomes; renal progression.

Copyright © 2015 by the American Society of Nephrology.

Figures

Figure 1.

Number, percentage, and distribution of individuals to be screened for CKD (N) and CKD cases detected (n) in the three screening approaches. Total study population: N=3411; total number of CKD cases, n=263.

Figure 2.

Age- and sex-adjusted hazard rates (with 95% confidence interval) for cardiovascular disease (CVD) events in individuals with CKD that were detected (light gray bars) or not detected (dark gray bars) per screening approach, with individuals without CKD at baseline (white bar) as reference.N, number of individuals; n, number of events; SES, socioeconomic status. *P<0.05 compared with non-CKD individuals; x=P<0.05 compared with detected CKD cases for the same approach.

Figure 3.

Age- and sex-adjusted rates of eGFR decline (with 95% confidence interval) in individuals with CKD that were detected (light gray bars) or not detected (dark gray bars) per screening approach, with individuals without CKD at baseline (white bar) as reference.N, number of individuals. *P<0.05 compared with non-CKD individuals; x=P<0.05 compared with detected CKD cases for the same approach.