偏性又称偏倚，是指在设计临床试验方案、执行临床试验、分析评价临床试验结果时，由于存在某些影响因素系统的倾向，致使疗效或安全性评价偏离真值。在临床试验中应尽可能地查明导致偏性的可能来源，采取措施加以限制。偏性的存在危及临床试验中得出正确结论的能力，偏性可能? Bias, also known as bias, refers to the design of clinical trial program, the implementation of clinical trials, analysis and evaluation of clinical trial results, due to the existence of certain system factors tend to lead to efficacy or safety evaluation deviate from the true value. In clinical trials, as far as possible to identify possible sources of bias, to take measures to be limited. The existence of biases endangers the ability to derive the correct conclusions from clinical trials, and is biases possible?