Not long ago, clinical trials involved 100% onsite monitoring in an effort to ensure high data quality. But how effective and efficient was that process? Several analyses have shown that only 1-2% of data is corrected as a result of source data verification (SDV). Therefore, the concept of risk-based monitoring (RBM) was born. The goal was to complete a more targeted monitoring (<100% SDV) without compromising patient safety or data quality.