Institute of General Practice, University Hospital Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
BMC Geriatr. 2013 Sep 10;13:92. doi: 10.1186/1471-2318-13-92.
In elderly patients chronic kidney disease often limits drug prescription. As several equations for quick assessment of kidney function by estimating glomerular filtration rate (eGFR) and several different clinical recommendations for drug dose adjustment in renal failure are published, choosing the correct approach for drug dosage is difficult for the practitioner. The aims of our study were to quantify the agreement between eGFR-equations grouped by creatinine-based or cystatin C-based and within the groups of creatinine and cystatin C-based equations and to investigate whether use of various literature and online references results in different recommendations for drug dose adjustment in renal disease in very elderly primary care patients.
We included 108 primary care patients aged 80 years and older from 11 family practices into a cross-sectional study. GFR was estimated using two serum creatinine-based equations (Cockroft-Gault, MDRD) and three serum cystatin C-based equations (Grubb, Hoek, Perkins). Concordance between different equations was quantified using intraclass correlation coefficients (ICCs). Essential changes in drug doses or discontinuation of medication were documented and compared in terms of estimated renal function as a consequence of the different eGFR-equations using five references commonly used in the US, Great Britain and Germany.
In general, creatinine-based equations resulted in lower eGFR-estimation and in higher necessity of drug dose adjustment than cystatin C-based equations. Concordance was high between creatinine-based equations alone (ICCs 0.87) and between cystatin C-based equations alone (ICCs 0.90 to 0.96), and moderate between creatinine-based equations and cystatin C-based equations (ICCs 0.54 to 0.76). When comparing the five different references consulted to identify necessary drug dose adjustments we found that the numbers of drugs that necessitate dose adjustment in the case of renal impairment differed considerably. The mean number of recommended changes in drug dosage ranged between 1.9 and 2.5 per patient depending on the chosen literature reference.
Our data suggest that the choice of the literature source might have even greater impact on drug management than the choice of the equation used to estimate GFR alone. Efforts should be deployed to standardize methods for estimating kidney function in geriatric patients and literature recommendations on drug dose adjustment in renal failure.
在老年患者中，慢性肾脏病常常限制了药物的使用。目前有多种通过估算肾小球滤过率（eGFR）来快速评估肾功能的方程，以及针对肾功能衰竭时药物剂量调整的多种不同临床建议，因此临床医生很难选择正确的药物剂量调整方法。我们的研究目的是定量评估基于肌酐和基于胱抑素 C 的 eGFR 方程之间的一致性，以及在肌酐和胱抑素 C 方程组内的一致性，并探讨在非常高龄的初级保健患者中，使用不同的文献和在线参考资料是否会导致不同的肾功能衰竭药物剂量调整建议。
我们纳入了 11 家家庭诊所的 108 名 80 岁及以上的初级保健患者进行横断面研究。使用两种基于血清肌酐的方程（Cockroft-Gault、MDRD）和三种基于血清胱抑素 C 的方程（Grubb、Hoek、Perkins）来估计肾小球滤过率。使用组内相关系数（ICCs）来定量评估不同方程之间的一致性。根据不同的 eGFR 方程，记录药物剂量的必要改变或停药，并根据估计的肾功能进行比较，同时比较了美国、英国和德国常用的五种参考文献。
一般来说，基于肌酐的方程会导致较低的 eGFR 估计值和更高的药物剂量调整需求，而基于胱抑素 C 的方程则相反。单独使用肌酐方程时，一致性较高（ICCs 0.87），单独使用胱抑素 C 方程时，一致性也很高（ICCs 0.90 至 0.96），而肌酐方程和胱抑素 C 方程之间的一致性则处于中等水平（ICCs 0.54 至 0.76）。当比较五种不同的参考文献来确定必要的药物剂量调整时，我们发现，在肾功能受损的情况下，需要调整剂量的药物数量有很大差异。根据所选文献的不同，建议调整药物剂量的平均数量在每位患者 1.9 至 2.5 种之间。
我们的数据表明，文献来源的选择对药物管理的影响可能甚至大于单独使用估计 GFR 的方程的选择。应该努力标准化评估老年患者肾功能的方法，并标准化肾功能衰竭时药物剂量调整的文献建议。
