Proper and complete documentation of harmful drug effects is difficult. Spontaneous reporting rates to regulatory agencies are low – approximately 1% – and ongoing monitoring is passive in many countries.
正确完整地证明有害的药物效果困难重重。主动向监管部门汇报的比率十分低——大约只有1%——并且在许多国家中，保持不断的监测处于消极态势。