Conduct↦Statistic Methodology↦Interim Analysis↦Procedures
What is it? Why is it important?
During study conduct, Interim Analyses (IA) are performed as described in the study protocol and, if applicable, in the Statistical Analysis Plan (SAP).
The results of an IA may trigger a re-evaluation of the ongoing study. Aspects to consider are study:
- Futility: A high likelihood that the intervention is ineffective or has only minimal benefit
- Safety: Unacceptable safety risks to participants (e.g. an unacceptable risk-benefit ratio)
- Efficacy: A significant beneficial treatment effect with study success being declared early
The expert consultation of an Independent Data Monitoring Committee (IDMC) (i.e. also called Data Safety Monitoring Board (DSMB) – focuses on safety) can advise the SP-INV on how to proceed with the study.
Conclusion could be that:
- Participant safety continues to be guaranteed in the ongoing study (few adverse events), thus the study can continue
- Safety concerns outweigh study benefit (i.e. a negative shift in the risk benefit-ratio of the study). Thus the study must be stopped
What do I need to do?
As a SP-INV:
- Perform IA(s) as described in the study protocol and, if applicable, the SAP
- Ask the statistician to forward the results of the IA to the IDMC/DSMB for assessment
- In the event of a blinded study, ensure the blind is not broken during the analysis. In the event results indicate futility, safety or efficacy concerns, allow IDMC/DSMB to assess the study unblinded (i.e. the identification of the intervention and control group)
- Make informed decisions regarding the continuation of the study, based on IDMC/DSMB recommendations (e.g. study stop, changes in study inclusion/exclusion criteria, sample size adjustments)
Note: The introduction of additional (not-planned) IAs or the omission of a planned IA, require a protocol amendment. An amendment must be approved by the Ethics Committee (EC) and if applicable RA (e.g. Swissmedic for risk-category B and C studies)
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 Topic E9 – see in particular
- 4.1 Trial monitoring and interim analysis
- 4.2 Changes in inclusion and exclusion criteria
- Sample size adjustments
- 4.5 Interim Analysis and early stopping
- 4.6 Role of IDMC
- 7.1 Evaluation and reporting
Swiss Law
ClinO – see in particular article
- Art. 2b Definition of intervention