Miskulin Dana C, Martin Alice A, Brown Richard, Fink Nancy E, Coresh Josef, Powe Neil R, Zager Philip G, Meyer Klemens B, Levey Andrew S
Division of Nephrology, Tufts-New England Medical Center, Boston, MA 02111, USA.
Nephrol Dial Transplant. 2004 Feb;19(2):413-20. doi: 10.1093/ndt/gfg571.
A valid and practical measure of comorbid illness burden in dialysis populations is greatly needed to enable unbiased comparisons of clinical outcomes. We compare the discriminatory accuracy of 1 year mortality predictions derived from four comorbidity instruments in a large representative US dialysis population.
Comorbidity information was collected using the Index of Coexistent Diseases (ICED) in 1779 haemodialysis patients of a national dialysis provider between 1997 and 2000. Comorbidity was also scored according to the Charlson Comorbidity Index (CCI), Wright-Khan and Davies indices. Relationships of instrument scores with 1 year mortality were assessed in separate logistic regression analyses. Discriminatory ability was compared using the area under the receiver-operating characteristics curve (AUC), based on predictions of each regression model.
When mortality was predicted using comorbidity and age, the ICED better discriminated between survivors and those who died (AUC 0.72) as compared with the CCI (0.67), Wright-Khan (0.68) and Davies (0.68) indices. Upon addition of race and serum albumin, predictive accuracy of each model improved further (AUCs of the ICED, 0.77; CCI, 0.75; Wright-Khan Index, 0.75; Davies Index, 0.74).
The ICED had greater discriminatory ability than the CCI, Davies and Wright-Khan indices, when age and a comorbidity index were used alone to predict 1 year mortality; however, the differences among instruments diminished once serum albumin, race and the cause of ESRD were accounted for. None of the currently available comorbidity instruments tested in this study discriminated mortality outcomes particularly well. Assessing comorbidity using the ICED takes significantly more time. Identifying the key prognostic comorbid conditions and weighting these according to outcomes in a dialysis population should increase accuracy and, with restriction to a finite number of items, provide a practical means for widespread comorbidity assessment.
为了能够对临床结果进行无偏倚比较，非常需要一种有效且实用的方法来衡量透析人群的共病负担。我们在美国一个具有代表性的大型透析人群中比较了四种共病工具对1年死亡率预测的判别准确性。
1997年至2000年间，使用共存疾病指数（ICED）收集了一家全国性透析服务提供商的1779例血液透析患者的共病信息。共病情况还根据Charlson共病指数（CCI）、Wright-Khan指数和Davies指数进行评分。在单独的逻辑回归分析中评估工具评分与1年死亡率之间的关系。基于每个回归模型的预测，使用受试者操作特征曲线（AUC）下的面积比较判别能力。
当使用共病情况和年龄预测死亡率时，与CCI（0.67）、Wright-Khan指数（0.68）和Davies指数（0.68）相比，ICED在区分存活者和死亡者方面表现更好（AUC为0.72）。加入种族和血清白蛋白后，每个模型的预测准确性进一步提高（ICED的AUC为0.77；CCI为0.75；Wright-Khan指数为0.75；Davies指数为0.74）。
当单独使用年龄和共病指数预测1年死亡率时，ICED的判别能力高于CCI、Davies指数和Wright-Khan指数；然而，一旦考虑血清白蛋白、种族和终末期肾病的病因，各工具之间的差异就会减小。本研究中测试的现有共病工具均未特别好地判别死亡率结果。使用ICED评估共病情况需要显著更多时间。识别关键的预后共病情况并根据透析人群的结果对其进行加权，应能提高准确性，并且通过限制项目数量，提供一种广泛进行共病评估的实用方法。
