What is it? Why is it important?
An Interim Analysis (IA) is done before all data collection is complete in order to evaluate study safety and efficacy while the study is still ongoing, such as:
- Safety concerns (e.g. a potentially high frequency of adverse events during study treatment)
- Efficacy concerns (e.g. treatment effect compared to placebo is highly superior or has no added benefit)
Timing and rational of an IA must be documented in the study protocol.
An IA can also be beneficial in studies lasting for long periods of time. This might facilitate data cleaning during study conduct and ensure data quality. In addition, IAs and data publications might be an integral strategy of longitudinal studies.
In order to protect participant safety and rights the EC might request that an IA be performed during study conduct.
A Data Safety Monitoring Board (DSMB) consists of a group of individuals independent of the study, who are experts in relevant areas.
The board reviews the accumulated data and findings from an IA and advises the SP-INV on the continued:
- Safety of study participants
- Validity of the study
- Scientific merit of the study.
What do I need to do?
- Describe the rational and requirement of an IA in your study
- Plan the appropriate timing of an IA (e.g. upon inclusion of 10 study participants, after 6 month study conduct months, on a quarterly basis)
- Frequency and rational for repeated IAs
- Type of statistical analysis used
- Describe implications based on analytical results (e.g. upper- lower tolerability defining study continuation, adaptations, or study stop)
- Plan to set-up a DSMB who provides expert advice on how to proceed with the study
For more information refer to Statistics in this Study Guide.
Where can I get help?
Your local CTU↧ can support you with experienced staff regarding this topic
Basel, Clinical Trials Unit, CTU, dkf.unibas.ch
Bellinzona, 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.ctc.usz.ch
ICH GCP E6(R2) – see in particular guidelines
- 5.4.1 Interim report
- 5.5 Trial Management, data handling, and record keeping
- 6.9.1 Statistics, interim analysis
ICH E9 – Statistical Principals for Clinical Trials
ISO 14155:2020 Medical devices see in particular section (access liable to costs)
- 6.2 Risk management
- A.7 Statistical design and analysis