Concept↦Safety↦Safety in Studies↦Risk-Benefit Ratio
What is it? Why is it important?
In a study, the risk-benefit ratio is the proportion of all possible risks over anticipated benefits. Its assessment serves to mitigate potential risks in order to protect participants.
Each study carries its own risks and benefits. There is never zero-risk, but it must be minimised as far as possible to guarantee risks remain acceptable to participants.
The risk-benefit ratio:
- Of a study must be positive for the study to be initiated (study benefits are higher than risks). EC/RA only authorise studies where benefits are judged greater than risks
- Is continuously assessed during study conduct. This is required to ensure the ratio remains unchanged. In the event of an unfavourable shift, additional protective safety measures must be implemented or the study is stopped
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Based on submitted documents by study researchers.
EC is responsible to review and approve any expected study risks based on:
- Submitted study documents
- The ratio between the likely risks and burdens and the expected benefits to participants
- Measures taken by the SP-INV / Site-INV to minimise risks and burdens
RA (e.g. Swissmedic) is responsible to:
- Review safety and quality of IMP, IMD
- Reflect the current state of scientific knowledge based on the information provided in the IB
- Ensure that IMP/IMD risk-mitigating measures are taken into account by the SP-INV
- Ensure risks, benefits, including risk mitigating measures are correctly reported in the study protocol
The expected level of risk depends on the:
- IMP/IMD under investigation
- The type of intervention or study design (e.g. placebo controlled, randomised, single arm)
- Study phase (First-in-man, phase I, II and III for IMP / MP post-marketing stage or pilot / pivotal stage for IMD / MD for post-marketing stage)
- Disease and current health status of participants (e.g. risk for severe AEs in multimorbid participants may be more acceptable than for healthy volunteers)
- Study population (e.g. pregnant women, children, participants lacking capacity)
What do I need to do?
As a SP-INV:
- Select a risk appropriate study design for the target group under investigation (e.g. health / disease status, vulnerable population such as children, pregnant women)
- Identify and assess expected participant:
- Risks and burdens with regard to the planned IMP/IMD intervention
- Benefits (e.g. prevent progression of disease, improve quality of life)
- Describe in the study protocol expected risks and benefits and set them in relation to the planned study population
- Establish as applicable, SOPs, WIs and / or a safety management plan, a DSMB to monitor, evaluate and report risk occurrence during study conduct
- Define and describe mitigating measures to reduce or control risks
For more information refer to Quality and Risk in this study guide.
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- Risks for study participants should never be disproportionate to or outweigh any expected benefits
- In the event of an unfavourable shift in the risk-benefit ratio for participants:
- Amend the patient information
- Inform study participants
- If applicable, ask the participant to re-consent to study participation
To be considered
- For diseases with a high level of health impairment (e.g. multimorbid participants and cancer patients) a higher risk level is acceptable. However, for conditions with a low level of health impairment (e.g. headache), only low risks would be acceptable
- During study conduct the risk-benefit ratio should be re-assessed on an ongoing basis or at least in the event of safety concerns
Where can I get help?
Your local CTU↧ can support you with experienced staff regarding this topic
Basel, Departement Klinische Forschung, CTU, dkf.unibas.ch
Lugano, Clinical Trials Unit, CTU-EOC, www.ctueoc.ch
Bern, Clinical Trials Unit, CTU, www.ctu.unibe.ch
Geneva, Clinical Research Center, CRC, crc.hug.ch
Lausanne, Clinical Research Center, CRC, www.chuv.ch
St. Gallen, Clinical Trials Unit, CTU, www.kssg.ch
Zürich, Clinical Trials Center, CTC, www.usz.ch
References
ICH E8(R1) – see in particular guideline
- 3 Designing quality into clinical studies
Declaration of Helsinki – see in particular principles
- 4, 7-9, 14 General principles
- 16-18 Risks, burdens and benefits
- 20 Justification of research in vulnerable groups
Swiss Law
HRA – see in particular articles
- Art. 12 Risks and burdens
- Art. 15 Safety and protective measures
ClinO – see in particular articles
- Art. 25 EC review areas
- Art. 32 RA review areas
ClinO-MD – see in particular articles
- Art.11 EC review areas
- Art. 17 RA review areas
HRO – see in particular article
- Art. 15 EC review areas