Department of Social Epidemiology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Hakubi Center, Kyoto University, Kyoto, Japan.
JAMA Health Forum. 2024 Mar 1;5(3):e235445. doi: 10.1001/jamahealthforum.2023.5445.
Chronic kidney disease (CKD) is a major public health issue, affecting 850 million people worldwide. Although previous studies have shown the association between socioeconomic status and CKD, little is known about whether this association exists in countries such as Japan where universal health coverage has been mostly achieved.
To identify any association of income-based disparity with development of impaired kidney function among the working population of Japan.
DESIGN, SETTING, AND PARTICIPANTS: This was a nationwide retrospective cohort study of adults aged 34 to 74 years who were enrolled in the Japan Health Insurance Association insurance program, which covers approximately 40% of the working-age population (30 million enrollees) in Japan. Participants whose estimated glomerular filtration rate (eGFR) had been measured at least twice from 2015 to 2022 were included in the analysis, which was conducted from September 1, 2021, to March 31, 2023.
Individual income levels (deciles) in the fiscal year 2015.
Odds ratios were calculated for rapid CKD progression (defined as an annual eGFR decline of more than 5 mL/min/1.73 m2), and hazard ratios, for the initiation of kidney replacement therapy (dialysis or kidney transplant) by income level deciles in the fiscal year 2015.
The study population totaled 5 591 060 individuals (mean [SD] age, 49.2 [9.3] years) of whom 33.4% were female. After adjusting for potential confounders, the lowest income decile (lowest 10th percentile) demonstrated a greater risk of rapid CKD progression (adjusted odds ratio, 1.70; 95% CI, 1.67-1.73) and a greater risk of kidney replacement therapy initiation (adjusted hazard ratio, 1.65; 95% CI, 1.47-1.86) compared with the highest income decile (top 10th percentile). A negative monotonic association was more pronounced among males and individuals without diabetes and was observed in individuals with early (CKD stage 1-2) and advanced (CKD stage 3-5) disease.
The findings of this retrospective cohort study suggest that, even in countries with universal health coverage, there may be a large income-based disparity in the risk of rapid CKD progression and initiation of kidney replacement therapy. These findings highlight the importance of adapting CKD prevention and management strategies according to an individual's socioeconomic status, even when basic health care services are financially guaranteed.
慢性肾脏病（CKD）是一个主要的公共卫生问题，影响着全球 8.5 亿人。尽管先前的研究表明社会经济地位与 CKD 之间存在关联，但在日本等已经实现全民健康覆盖的国家，这种关联是否存在尚不清楚。
确定日本劳动人口中基于收入的差异与受损肾功能发展之间的任何关联。
设计、地点和参与者：这是一项全国性的回顾性队列研究，纳入了年龄在 34 至 74 岁之间、参加日本健康保险协会保险计划的成年人，该计划涵盖了日本约 40%的劳动年龄人口（3000 万参保人）。在 2015 年至 2022 年期间至少两次测量估计肾小球滤过率（eGFR）的参与者被纳入分析，分析于 2021 年 9 月 1 日至 2023 年 3 月 31 日进行。
2015 财年的个人收入水平（十分位数）。
计算了 eGFR 每年下降超过 5 mL/min/1.73 m2（定义为快速 CKD 进展）的比值比，以及 2015 财年按收入水平十分位数计算的肾脏替代治疗（透析或肾移植）起始的风险比。
研究人群总计 5591060 人（平均[标准差]年龄，49.2[9.3]岁），其中 33.4%为女性。在调整了潜在混杂因素后，最低收入十分位数（最低的 10%）的快速 CKD 进展风险更高（调整比值比，1.70；95%置信区间，1.67-1.73），肾脏替代治疗开始的风险也更高（调整风险比，1.65；95%置信区间，1.47-1.86），与最高收入十分位数（最高的 10%）相比。这种负向的单调关联在男性和无糖尿病患者中更为明显，在早期（CKD 1-2 期）和晚期（CKD 3-5 期）疾病患者中也观察到了。
这项回顾性队列研究的结果表明，即使在全民健康覆盖的国家，快速 CKD 进展和肾脏替代治疗开始的风险也可能存在很大的基于收入的差异。这些发现强调了根据个体的社会经济地位调整 CKD 预防和管理策略的重要性，即使基本的医疗保健服务在经济上得到保障。
