Department of Biostatistics, Abant Izzet Baysal University, Bolu 14030, Turkey.
Department of Biostatistics, Erciyes University, Kayseri 38280, Turkey.
Biomed Res Int. 2021 Jul 21;2021:6612464. doi: 10.1155/2021/6612464. eCollection 2021.
Peritoneal dialysis (PD) is a frequently used and growing therapy for end-stage renal diseases (ESRD). Survival analysis of PD patients is an ongoing research topic in the field of nephrology. Several biochemical parameters (e.g., serum albumin, creatinine, and blood urea nitrogen) are measured repeatedly in the follow-up period; however, baseline or averaged values are primarily associated with mortality. Although this strategy is not incorrect, it leads to information loss, resulting in erroneous conclusions and biased estimates. This retrospective study used the trajectory of common renal function indexes in PD patients and mainly investigated the association between serum albumin change and mortality. Furthermore, we considered patient-specific variability in serum albumin change and obtained personalized dynamic risk predictions for selected patients at different follow-up thresholds to investigate the effect of serum albumin trajectories on patient-specific mortality. We included 417 patients from the Erciyes University Nephrology Department whose data were retrospectively collected using medical records. A joint modeling approach for longitudinal and survival data was used to investigate the relationship between serum albumin trajectory and mortality of PD patients. Results showed that averaged serum albumin levels were not associated with mortality. However, serum albumin change was significantly and inversely associated with mortality (HR: 2.43, 95% CI: 1.48 to 4.16). Risk of death was positively associated with peritonitis rate, hemodialysis history, and the total number of comorbid and renal diseases with hazard ratios 1.74, 3.21, and 1.41. There was also significant variability between patients. The personalized risk predictions showed that overall survival estimates were not representative for all patients. Using the patient-specific trajectories provided better survival predictions within the follow-up period as more data become available in serum albumin levels. In conclusion, using the trajectory of risk predictors via an appropriate statistical method provided better predictive accuracy and prevented biased findings. We also showed that personalized risk predictions were much informative than overall estimations in the presence of significant patient variability. Furthermore, personalized estimations may play an essential role in monitoring and managing patients during the follow-up period.
腹膜透析（PD）是终末期肾脏疾病（ESRD）常用且不断发展的治疗方法。PD 患者的生存分析是肾脏病学领域的一个持续研究课题。在随访期间，反复测量了几个生化参数（如血清白蛋白、肌酐和血尿素氮）；然而，基线或平均值主要与死亡率相关。尽管这种策略没有错，但它会导致信息丢失，从而得出错误的结论和有偏差的估计。这项回顾性研究使用 PD 患者常见肾功能指标的轨迹，主要研究了血清白蛋白变化与死亡率之间的关系。此外，我们考虑了血清白蛋白变化的患者特异性变异性，并为不同随访阈值下的选定患者获得了个性化的动态风险预测，以研究血清白蛋白轨迹对患者特异性死亡率的影响。我们纳入了来自埃尔吉耶斯大学肾病科的 417 名患者，这些数据是通过病历回顾性收集的。使用纵向和生存数据的联合建模方法来研究血清白蛋白轨迹与 PD 患者死亡率之间的关系。结果表明，平均血清白蛋白水平与死亡率无关。然而，血清白蛋白变化与死亡率显著负相关（HR：2.43，95%CI：1.48 至 4.16）。死亡风险与腹膜炎发生率、血液透析史以及合并症和肾脏疾病的总数呈正相关，危险比分别为 1.74、3.21 和 1.41。患者之间也存在显著的变异性。个性化风险预测表明，在随访期间，由于血清白蛋白水平的更多数据可用，整体生存估计对所有患者均不具有代表性。使用适当的统计方法通过风险预测器的轨迹提供了更好的预测准确性，并防止了有偏差的发现。我们还表明，在存在显著患者变异性的情况下，个性化风险预测比总体估计更具信息性。此外，个性化估计在随访期间可能在监测和管理患者方面发挥重要作用。
