A Pilot Study of Opportunistic Chronic Kidney Disease Screening in Primary Care Using a Clinical Decision Support System

<b>Background/Objectives</b>: CKD affects over 10% of adults and is often silent, delaying diagnosis. Opportunistic primary care screening supported by clinical decision support systems (CDSSs) may improve detection with minimal burden. We evaluated the feasibility, diagnostic yield, clinical actions, and reagent costs of a CDSS-enabled, albuminuria-first program using eGFR. <b>Methods</b>: This one-year cross-sectional intervention screened all patients receiving routine laboratory tests at a primary care center using a CDSS integrating prior labs, medical records, and guideline rules. Eligibility required patients age 60-85 (Group 1) or 18-59 with hypertension, diabetes, or cardiovascular disease (Group 2). Eligible patients received urine albumin and eGFR testing with standard phlebotomy; abnormal findings triggered confirmatory tests. Outcomes were diagnostic yield, KDIGO risk stratification, referral patterns, and reagent costs. The CDSS surfaced prompts and pre-populated orders in the laboratory interface. <b>Results</b>: Of 7722 targets, 1892 (24.5%) were flagged (34.2% of Group 2, 7.9% of Group 1), and 1774 (93.8%) completed screening. We identified 104 new CKD cases (5.9%): 75% KDIGO moderate risk, 19% high, and 6% very high. Twenty patients (1.1%) met criteria for nephrology referral. Guideline-directed therapy was started or optimized in 90%, and 62.5% received a new CKD diagnosis code. Reagent costs averaged EUR 0.51 per person screened and EUR 11.14 per CKD case detected. Most cases were early-stage and manageable in primary care. <b>Conclusions</b>: CDSS-enabled opportunistic screening in primary care is feasible, acceptable, and low-cost. It identifies previously unrecognized CKD at modest expense, enabling early interventions that may slow progression and reduce cardiovascular events. Scaling with follow-up should assess long-term outcomes.