Net efficacy adjusted for risk: further developments

Use of available clinical evidence to extrapolate drug effects from adults to children

The extrapolation of the benefit risk ratio from adults to children is performed during drug development and often implicitly used by many paediatricians when prescribing off-label drugs in children. This is due to the specific constraints of paediatric clinical research leading to a lack of safety and efficacy data in children. Extrapolation frameworks for drug development have been proposed by several regulatory agencies. Using a meta-epidemiological approach, we explored the similarities and differences of the benefit, the benefit risk ratio and the perceived placebo effect between adults and children from meta-analyses including randomized double-blinded placebo-controlled trials evaluating a drug intervention in an indication in adults and children with separate data for both populations. We also explored the use of the effect model using adult data to predict the treatment effect in children and to calibrate future paediatric clinical trials. Our research highlights the importance of using all available evidence and quantitative methods before extrapolating the benefit risk ratio from adults to children and carrying out new studies in the context of the existing evidence. More generally, this should be applied to any research to avoid a waste of time and resources invested.

Balancing benefit and risk of medicines: a systematic review and classification of available methodologies

BACKGROUND

The need for formal and structured approaches for benefit-risk assessment of medicines is increasing, as is the complexity of the scientific questions addressed before making decisions on the benefit-risk balance of medicines. We systematically collected, appraised and classified available benefit-risk methodologies to facilitate and inform their future use.

METHODS

A systematic review of publications identified benefit-risk assessment methodologies. Methodologies were appraised on their fundamental principles, features, graphical representations, assessability and accessibility. We created a taxonomy of methodologies to facilitate understanding and choice.

RESULTS

We identified 49 methodologies, critically appraised and classified them into four categories: frameworks, metrics, estimation techniques and utility survey techniques. Eight frameworks describe qualitative steps in benefit-risk assessment and eight quantify benefit-risk balance. Nine metric indices include threshold indices to measure either benefit or risk; health indices measure quality-of-life over time; and trade-off indices integrate benefits and risks. Six estimation techniques support benefit-risk modelling and evidence synthesis. Four utility survey techniques elicit robust value preferences from relevant stakeholders to the benefit-risk decisions.

CONCLUSIONS

Methodologies to help benefit-risk assessments of medicines are diverse and each is associated with different limitations and strengths. There is not a 'one-size-fits-all' method, and a combination of methods may be needed for each benefit-risk assessment. The taxonomy introduced herein may guide choice of adequate methodologies. Finally, we recommend 13 of 49 methodologies for further appraisal for use in the real-life benefit-risk assessment of medicines.