in this case a gap exists between the efficacy of the product assessed during clinical trials and its observed effectiveness in real life use while this gap is widely recognised the safety and effectiveness of new technologies is only rarely assessed through formal reevaluation recent evidence shows that health technology reassessment is seldom used in oecd countries a third of oecd health care systems rely on periodic reassessment after technologies are included in the range of benefits covered by public funding auraaen et al