Page 60 - ESHRE2019

Intention to treat (ITT)
The least biased way to analyse trial results
Principles of ITT (all 3 must be met)
1. keep participants in the intervention groups to which they were randomized, regardless of the intervention they actually received
2. measure outcome data on all participants
3. include all randomized participants in the analysis
Not usually possible to get outcome data for drop-outs so imputation needed (e.g. assume no live birth in women who drop-out).
5. Incomplete outcome data
Considerations
• How many data are missing from each group?
• Why is it missing?
• e.g. side effects/adverse event, refusal
• reasons can have different in each group
• How were the data analysed? Or can we analyse appropriately anyway i.e. using ITT?
• May reach different conclusions for different outcomes • may be more missing data at different time points – ongoing
pregnancy vs live birth
• some outcomes may have more missing data e.g. sensitive questions, invasive tests
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