| [ Summary ] |
Target ranges of laboratory measurement in the current CKD-MBD guidelines were primarily determined by large observational studies examining the association between laboratory values and mortality. However, suggested optimal ranges are often different in observational studies compared to randomized controlled trials (RCTs). For example, in the field of diabetes mellitus treatment, cohort studies have shown that lower hemoglobin A1C levels are associated with better clinical outcomes. However, intensive control of blood sugar resulted in higher mortality in RCTs. In order to advocate truely meaningful guidelines, we must conduct many RCTs. In other words, a paradigm shift from "setting targets" to "comparing the intensity of a medical treatment" is necessary, because target ranges may be dependent on the type of drug or intervention. If we cannot conduct RCTs because of ethical reasons or economic issues, sophisticated analytical methods such as propensity score-based analysis and facility-level analysis should be employed in observational studies. |