Rationale & Objective

Intact cognition is generally a prerequisite for navigating through and completing evaluation for kidney transplantation. Despite kidney transplantation being contraindicated for those with severe dementia, screening for more mild forms of cognitive impairment before referral is rare. Candidates may have unrecognized cognitive impairment, which may prolong evaluation, elevate mortality risk, and hinder access to kidney transplantation. We estimated the burden of cognitive impairment and its association with access to kidney transplantation and waitlist mortality.

Study Design

Prospective cohort study.

Setting & Participants

3,630 participants (January 2009 to June 2018) with cognitive function measured (by the Modified Mini-Mental State Examination [3MS]) at kidney transplantation evaluation at 1 of 2 transplantation centers.

Predictors

Cognitive impairment (3MS score < 80).

Outcomes

Listing, waitlist mortality, and kidney transplantation.

Analytical Approach

We estimated the adjusted chance of listing (Cox regression), risk for waitlist mortality (competing-risks regression), and kidney transplantation rate (Poisson regression) by cognitive impairment. Given potential differences in cause of cognitive impairment among those with and without diabetes, we tested whether these associations differed by diabetes status using a Wald test.

Results

At evaluation, 6.4% of participants had cognitive impairment, which was independently associated with 25% lower chance of listing (adjusted HR, 0.75; 95% CI, 0.61-0.91); this association did not differ by diabetes status (P_interaction = 0.07). There was a nominal difference by diabetes status for the association between cognitive impairment and kidney transplantation rate (P_interaction = 0.05), while the association between cognitive impairment and waitlist mortality differed by diabetes status kidney transplantation rates (P_interaction = 0.02). Among candidates without diabetes, those with cognitive impairment were at 2.47 (95% CI, 1.31-4.66) times greater risk for waitlist mortality; cognitive impairment was not associated with this outcome among candidates with diabetes.

Limitations

Single measure of cognitive impairment.

Conclusions

Cognitive impairment is associated with a lower chance of being placed on the waitlist, and among patients without diabetes, with increased mortality on the waitlist. Future studies should investigate whether implementation of screening for cognitive impairment improves these outcomes.

中文翻译：

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患有或不患有糖尿病的肾移植候选者的认知功能、肾移植的获得性以及候补死亡率。

 理由和目标

完整的认知通常是完成肾移植评估的先决条件。尽管肾移植对于患有严重痴呆症的患者是禁忌的，但在转诊之前筛查较轻度的认知障碍的情况很少见。候选人可能存在未被识别的认知障碍，这可能会延长评估时间，增加死亡风险，并阻碍肾移植的获得。我们估计了认知障碍的负担及其与肾移植和候补死亡率的关系。

 研究设计

前瞻性队列研究。

 背景及参与者

在 2 个移植中心之一的肾移植评估中，对 3,630 名参与者（2009 年 1 月至 2018 年 6 月）进行了认知功能测量（通过改良简易精神状态检查 [3MS]）。

 预测因子

认知障碍（3MS 评分 < 80）。

 结果

名单、候补名单死亡率和肾移植。

 分析法

我们根据认知障碍估计了调整后的上市机会（Cox 回归）、等待名单死亡率风险（竞争风险回归）和肾移植率（泊松回归）。考虑到糖尿病患者和非糖尿病患者认知障碍原因的潜在差异，我们使用 Wald 检验测试了这些关联是否因糖尿病状态而异。

 结果

评估时，6.4% 的参与者患有认知障碍，这与 25% 的列出机会降低独立相关（调整后 HR，0.75；95% CI，0.61-0.91）；这种关联并不因糖尿病状态而异（ P_相互作用= 0.07）。认知功能障碍与肾移植率之间的关联因糖尿病状态而存在名义差异（ P_相互作用= 0.05），而认知功能障碍与候补死亡率之间的关联因糖尿病状态肾移植率而异（ P_相互作用= 0.02）。在没有糖尿病的候选人中，患有认知障碍的候选人的候补死亡风险高出 2.47 倍（95% CI，1.31-4.66）；糖尿病患者的认知障碍与这一结果无关。

 局限性

认知障碍的单一测量。

 结论

认知障碍与被列入候补名单的可能性较低有关，而在没有糖尿病的患者中，认知障碍与候补名单上的死亡率增加有关。未来的研究应该调查实施认知障碍筛查是否可以改善这些结果。