Population tracking
Describe who or what enters the study, how groups are formed and what happens during follow-up. Define eligibility, assignment or exposure and disposition, keeping people, episodes and events distinct.
Flows for this purpose
- Population identification and eligibility
Source population → candidate records or participants → eligibility → exclusions → eligible population
- Recruitment and enrollment
Potential participants → approached → screening and consent as protocol specifies → enrolled
- Allocation and treatment received
Assigned population → allocated arms → treatment received or not received
- Follow-up and disposition
Entry population → ongoing follow-up → completion, withdrawal, loss or other end states
- Analysis population derivation
Eligible or assigned population → declared inclusion rules → named analysis populations
- Exposure episode construction
Exposure records → episode rules → episodes → switching, gaps and discontinuation
- Population and observation periods
Define entry and follow-up rules
- Follow-up and disposition
Track visits losses and completion
- Groups and follow-up
Align eligibility exposure and observation
- Case and control selection
Define cases and sampling frames
- Sampling and participation
Define sample and participation denominators
- Participant and specimen selection
Track eligibility sampling and specimens
- Recruitment and allocation
Track enrollment assignment and treatment
- Recruitment and treatment
Track enrollment and intervention receipt
- Emulation eligibility and strategy assignment
Align entry strategies and time-zero
- Event-time risk-set control sampling
Sample eligible controls at events
- Self-controlled case and event selection
Identify cases and qualifying events
- Comparative change groups and adoption timing
Define units treatment and periods
- Prediction development population and suitability
Define development population and sources
- Nonrandomized recruitment and assignment
Document enrollment and assignment mechanisms
- Crossover recruitment and sequence allocation
Assign participants to treatment sequences
- Factorial recruitment and combination allocation
Assign participants across factor combinations
- Cluster and participant recruitment
Track both levels of enrollment
- Stepped-wedge cluster and participant selection
Define clusters and observation populations
- Dose-finding eligibility and cohort enrollment
Track evaluability and replacement rules
- Adaptive trial recruitment and allocation
Track enrollment and changing assignments
- Platform cohort and arm eligibility
Match participants to eligible comparisons