Evolution of the Burden of Carbapenem-Resistant Klebsiella pneumoniae Infections in the Elderly, 1990–2021: Global Trends, Regional Heterogeneity, and Health Inequalities

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a critical global health threat, particularl y for older adults. Understanding its precise burden and the associated health inequalities in the elderl y population is crucial for informed policy-making. Methods: Using data from the Global Burden of Disease 2021 stud y , we anal y zed deaths and disabilit y -adjusted life y ears attributable to and associated with CRKP in individuals aged ≥ 65 y ears from 1990 to 2021. We calculated age-standardized rates, assessed temporal trends via average annual percentage change (AAPC), and quantified health inequalities using the Slope Index of Inequality (SII) and Relative Concentration Index. Frontier anal y sis identified countries with the greatest potential for burden reduction. Results: The CRKP burden in the elderl y increased substantiall y over the past three decades, as the age-standardized mortalit y rate associated with CRKP more than doubled from 7.44 (95% CI: 5.65 to 9.23) to 16.17 (95% CI: 13.1 to 19.25) per 100,000 (AAPC = 2.54, p < 0.001), with the most rapid increases occurring in South Asia, Eastern Europe, and Latin America. Conversel y , high-income regions such as Western Europe witnessed substantial declines. Health inequalities widened markedl y , as the absolute mortalit y gap (SII) associated with CRKP expanded from −8.69 (95% CI: −11.25,−6.14) to −41.96 (95% CI: −46.97,−36.95), an approximate fivefold increase. Frontier anal y sis further revealed significant potentiall y avoidable burden in low- and middle-income countries, independent of socioeconomic development. Conclusion: Formal assessment of socioeconomic trends and health inequalities demonstrates an increasing concentration of the CRKP burden in low- and middle-income regions, exacerbating global health inequities. Combating this requires integrated strategies that combine antimicrobial stewardship and infection control with broader improvements in health care infrastructure and social determinants.