Negative values for "actual_day_relative_to_boost" vs visit

Hi, can you explain the timing in the “actual_day_relative_to_boost” column vs “visit” & “timepoint” columns. For example, in the challenge data the “actual_day_relative_to_boost” starts with negative values → to 0 per visit for each subject in the dataset. I want to make sure I’m understanding the timing correctly.

Hi @Lauren_Urban,

Thank you for your query.

Let me first clarify the difference between ‘actual_day_relative_to_boost’ and ‘planned_day_relative_to_boost.’ For the 2020_dataset cohort, which was recruited before the CMI-PB project began, there were several inconsistencies in mapping timepoints. To address this, we introduced ‘planned_day_relative_to_boost,’ which provided a more consistent reference across subjects. For the 2021, 2022, and 2023 cohorts, ‘planned_day_relative_to_boost’ and ‘actual_day_relative_to_boost’ align more closely since these cohorts were specifically recruited for the CMI-PB project. In addition, visit schedules for the 2020 cohort were inconsistent across subjects, while later cohorts had more standardized visits, resulting in better alignment with the planned schedule.

Both ‘actual_day_relative_to_boost’ and ‘planned_day_relative_to_boost’ refer to the timing relative to the date of vaccination. I believe “timepoint” in the data processing pipeline refers to ‘planned_day_relative_to_boost.’

I hope this clarifies the differences. Please feel free to reach out if you have any further questions!

Best,
Pramod