{
  "abstract": "Background Although avoidable mortality in South Korea has fallen substantially, whether socioeconomic inequality gradients have narrowed in parallel remains unclear. We assessed 13-year trends (2012–2024) in absolute and relative inequality in avoidable, preventable and treatable mortality across approximately 250 districts, weighting by district population rather than equal quintiles.Methods We adopted an ecological repeated cross-sectional design. District-level age-standardised mortality rates, calculated from cause-of-death microdata via the Korean Microdata Integrated Service, were linked to the Area Deprivation Index from census microdata. Districts were grouped into deprivation quintiles using ridit scores from actual population shares. The Slope Index of Inequality (SII) and Relative Index of Inequality (RII) were estimated annually via weighted least squares regression.Results Population-weighted avoidable mortality fell from 204.9 to 138.0 per 100 000 (−32.7%). Q1 (least deprived) held 34–35% of the population; Q5 (most deprived) only 4–5%. The SII for avoidable mortality showed no significant trend (56.6 to 53.5; slope+0.02/year, p=0.925), yet the RII rose from 0.276 to 0.388 (slope+0.011 /year, p<0.001). For treatable mortality, the SII climbed 65.4% (10.4 to 17.2, p<0.001) and the RII more than doubled (0.177 to 0.398, p<0.001). The preventable-to-treatable SII ratio converged from 4.4 to 2.1, and the RII ratio fell below unity for the first time in 2023, indicating that relative inequality in treatable mortality now exceeds that in preventable mortality.Conclusion Population-weighted analysis reveals an inequality paradox—stable absolute inequality (SII) with rising relative inequality (RII)—masked under conventional equal weighting, which yields a spurious SII decline and non-significant RII trend. Treatable mortality showed simultaneous widening of absolute (+65.4%) and relative (+124.9%) inequality, with its RII surpassing that of preventable mortality for the first time in 2023. These findings call for population-weighted monitoring and policies addressing structural barriers to healthcare access beyond financial coverage.",
  "authors": [
    {
      "affiliations": [
        "Busan Public Health Policy Institute, Busan, Korea"
      ],
      "name": "Younggyu Ko"
    },
    {
      "affiliations": [
        "Busan Public Health Policy Institute, Busan, Korea"
      ],
      "name": "Jung-Hyun Lee"
    }
  ],
  "title": "Population-weighted trends in absolute and relative inequalities in avoidable mortality by area deprivation in South Korea, 2012–2024",
  "uid": "56ebd162-b710-551d-9fcd-e7323807d964"
}