Evaluation of Concordance Among Different Drug Information Sources Regarding the Recommendations for Dosage Adjustment in Renal Impairment

Abstract

Background: It is very important to prescribe appropriate drugs and adjust medication and dosage for optimal disease management not only to maximize patient outcomes, but also to minimize adverse events. So, the accuracy of drug information and consistency among different resources would have a significant effect on drug therapy. Objectives: We aimed to evaluate the concordance among five drug information sources regarding the recommendations for dosage adjustment in renal impairment. Methods:The five drug information resources were selected the Korean National Formulary Drug (KNF), the British national formula 2013 (BNF 65), Daily Med in USA, Lexicomp-online, and Drug Prescribing in Renal Failure (DPRF, 5th ed.). After having classified the degrees of renal function and defined the terms used for the dosing methods, we analyzed the concordance in dosing recommendations in renal deficiency among the information sources by calculating Fleiss Kappa. Results: In the dosing adjustments of patients with renal insufficiency, there were some cases of contraindicated drugs that were not matched in each reference. Statistical analysis of the concordance of four references, except DPRF, and evaluation of 168 of the drugs that were mentioned in all four sources showed the Fleiss Kappa coefficientto be 0.243. This indicatesfair agreement among the data. Conclusion: Fair agreement was observed among 4 sources. This may be owing to discrepancies in the frequency of updating drug information sources. We suggest that the quantitative standard be used to classify renal function and to maintain consistency in definition of renal impairment.