Repeated Health Screening Measures and Incident Ischemic Stroke: Evidence From a Korean Population Study

Objectives: Ischemic stroke is influenced by long-term metabolic and renal deterioration; however, many risk prediction frameworks rely on single time-point measurements. We examined whether multi-period patterns in national health screening indicators are associated with incident ischemic stroke in Korea.Methods: Using customized National Health Insurance Service data with 3 biennial screenings (P1: 2013–2014; P2: 2015–2016; P3: 2017–2018), we identified incident ischemic stroke during 2019–2023 (Korean Standard Classification of Diseases-7 I63). After applying eligibility criteria and excluding individuals with missing screening values, we performed 1:1 propensity score matching on sex, 1-year age strata, and insurance type (97 454 matched pairs; n=194 908). Multi-period indicators included waist circumference increase ≥10%, sustained blood pressure ≥130/80 mmHg, sustained fasting glucose ≥126 mg/dL, proteinuria progression, and creatinine elevation in ≥2 periods (sex-specific thresholds). Associations were evaluated using conditional logistic regression; a comparator model used P3-only indicators.Results: In the multi-period model, stroke was associated with waist circumference increase ≥10% (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01 to 1.08), sustained blood pressure ≥130/80 mmHg (OR, 1.34; 95% CI, 1.31 to 1.37), sustained fasting glucose ≥126 mg/dL (OR, 1.66; 95% CI, 1.60 to 1.73), creatinine elevation in ≥2 periods (OR, 1.08; 95% CI, 1.06 to 1.10), and proteinuria progression (OR, 1.36; 95% CI, 1.32 to 1.39). In the P3-only model, all single-time-point indicators were associated with incident stroke (ORs, 1.08 to 1.47).Conclusions: Multi-year patterns in metabolic screening indicators were associated with incident ischemic stroke. Repeated health screening measurements may complement single time-point assessments and support continuous risk-factor monitoring and patient-centered prevention.