Spatiotemporal analysis of sudden infant death syndrome incidence in Korea, 2013-2023

This study examined temporal trends and geographic variation in sudden infant death syndrome (SIDS) incidence in Korea.

We analyzed a nationwide cardiac arrest registry to identify SIDS cases from 2013 to 2023. The study period was divided into 3 phases: pre-pandemic (2013-2019), pandemic (2020-2021), and post-pandemic (2022-2023). Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were estimated using Poisson regression, whereas standardized incidence ratios (SIRs) and 95% credible intervals (CrIs) were derived from Bayesian spatial models across all administrative districts. Spatial clustering was evaluated using Moran's I.

Overall, 884 eligible cases were identified: 575 in the pre-pandemic period, 172 in the pandemic period, and 137 in the post-pandemic period. SIDS incidence increased significantly from the mid-2010s onward, with an annual increase of approximately 8-9%. Compared with the pre-pandemic period, SIDS incidence was significantly higher during the pandemic period (IRR, 1.52; 95% CI, 1.28 to 1.80) and the post-pandemic period (IRR, 1.34; 95% CI, 1.11 to 1.61). Spatial clustering of SIDS incidence increased progressively across the 3 periods (Moran's I: 0.359, 0.654, and 0.952, respectively; p<0.001). Pyeongtaek-si, Gyeonggi-do, was the only district with a significantly increased SIR in the pre-pandemic period (posterior mean, 1.602; 95% CrI, 1.007 to 2.424); no district met the significance thresholds in the subsequent periods.

SIDS incidence in Korea has increased significantly since the mid-2010s, with progressive spatial clustering toward southwestern regions across the 3 study periods. The emergence of high-incidence and low-incidence clusters underscores the need for targeted interventions.