Table 1 Primary outcomes, (key) outcome measures, time points for each outcome and progression criteria for a full RCT
Primary quantitative outcomes | Outcome measure and time point for each outcome | Progression criteria for full RCTa |
|---|---|---|
A) Recruitment | 1) The proportion of contacted participants scoring above the threshold for anxiety or depressive symptoms and who accept the invitation to participate in the pilot trial throughout the study | 30 participants recruited in 6 months |
2) The number of participants recruited at each site | No criteria set | |
B) Retention rate | 2) The proportion of participants completing the study from enrolment (t0) to follow up (t4)* | ≥ 90% of enrolled participantsb |
C) Compliance | 3) The proportion of participants taking ≥ 80% probiotic/placebo product between t0 and t1* | 90% of participantsc |
4) The proportion of participants filling in electronic questionnaires at all time points (t0, t1 and t4)* | 90% of participants | |
5) The proportion of participants filling in the cry diary at t4 | 90% of participants | |
6) The proportion of participants filling in evaluation form at t4 | 90% of participants | |
7) The proportion of participants collecting all maternal vaginal and microbial samples at t0 and t1 | 90% of participantsd | |
8) The proportion of participants collecting all infant microbial samples at t0 and t1 | 90% of participants | |
9) The proportion of participants allowing collection of hair samples at t4 | 90% of participants | |
D) Participants’ impressions and experiences | 1) Experiences and level of acceptability of electronic questionnaires and collection of biological samples | No criteria set |
2) Level of satisfaction (positive/negative aspect) | No criteria set | |
3) Level of satisfaction (execution and organization) | No criteria set | |
4) Level of acceptability of the trial in practice (perceived burden)* | Mean score of ≤3 | |
5) Level of acceptability of the trial in principle (future participation)* | Mean score of ≥8 | |
Primary qualitative outcomes | ||
A) Recruitment | 1) Participants’ moment of decision to join the pilot trial | No criteria set |
2) Reasons for participation | No criteria set | |
3) Reasons for non-participation | No criteria set | |