Levin Nathan W, Handelman Garry J, Coresh Josef, Port Friedrich K, Kaysen George A
Renal Research Institute, New York, New York, USA.
Semin Dial. 2007 Nov-Dec;20(6):586-92. doi: 10.1111/j.1525-139X.2007.00366.x.
The term "reverse epidemiology" has been proposed to address the apparent different relationship between numerous risk factors and outcomes among dialysis patients: thus, obesity, hypertension, high cholesterol, and elevated creatinine all appear to be associated with decreased risk. Since this is contrary to the general findings in otherwise healthy populations, some kind of "reversal" has been suggested, that would be contrary to classical epidemiology. The authors describe several faults to this conception. The rules of epidemiology have not been reversed in dialysis patients. In fact, the complexity of the population implies a greater need for attention to the distinction between association and causation and the importance of confounding and bias. In particular existing subclinical and clinical disease which is very common among dialysis patients can change associations so drastically that they are dominated by different causal pathways than those seen in the general population. For example, lower cholesterol is a better marker of poor health than of a healthy diet and thus is associated with different outcomes. To the extent the term reverse epidemiology implies either epidemiology or biology is different in dialysis patients it can be misleading and detrimental. The differences between risk factors in end-stage renal disease (ESRD) and other individuals are surely important, but can themselves be the basis of excellent epidemiology, applied with the classic rules developed for this discipline with the goal of uncovering causal association and hypotheses to be tested in clinical trials.
“反向流行病学”这一术语已被提出，用于描述透析患者中众多风险因素与预后之间明显不同的关系：因此，肥胖、高血压、高胆固醇和肌酐升高似乎都与风险降低有关。由于这与健康人群中的一般研究结果相反，有人提出了某种“逆转”，这与经典流行病学相悖。作者描述了这一概念的几个缺陷。在透析患者中，流行病学规律并未被逆转。事实上，人群的复杂性意味着更需要关注关联与因果关系的区别以及混杂因素和偏倚的重要性。特别是在透析患者中非常常见的现有亚临床和临床疾病，会极大地改变关联，以至于它们由与普通人群中所见不同的因果途径主导。例如，较低的胆固醇是健康状况不佳的更好指标，而非健康饮食的指标，因此与不同的预后相关。就“反向流行病学”这一术语意味着透析患者的流行病学或生物学有所不同而言，它可能会产生误导且有害。终末期肾病（ESRD）患者与其他个体的风险因素差异固然重要，但这些差异本身可以成为出色流行病学的基础，应用该学科经典规则以揭示因果关联，并提出在临床试验中进行检验的假设。
