Recruitment
Advanced Recruitment Forecast
Plan a realistic site-activation ramp, allow time before sites begin recruiting and forecast whole randomised patient counts.
Your assumptions
Build a recruitment forecast
Enter your own study assumptions. The example is illustrative, not a clinical benchmark. Yellow fields are editable.
Recruitment rates by site performance
Enter each rate per month or per year—the other field updates automatically. Rates are randomised patients per site, not screened patients. Percentages below are of recruiting sites only and must total 100%.
High-recruiting sites
Medium-recruiting sites
Low-recruiting sites
Yearly rate = monthly rate × 12. Converted values may be rounded for display; calculations retain the full rate you entered.
Enter your study assumptions to see the forecast.
Cumulative recruitment forecast
The blue line shows whole randomised patient counts obtained by rounding the cumulative expected-value forecast to the nearest patient (0.5 rounds up). The dashed line is the target.
Monthly site activation
Whole sites per month: a gradual start, steadier middle and late tail. The schedule always totals the planned sites.
View monthly recruitment calculations
Patient counts are whole numbers. Monthly patients are calculated from the change in rounded cumulative patients, so they always reconcile. “Recruiting sites” is an expected site equivalent and may be fractional.
| Month | Month begins | New sites | Sites activated | Sites contributing (expected equivalents) | Randomised this month | Cumulative randomised |
|---|
How it works
Model assumptions
Site activation: Enter the months needed to activate all sites. The model allocates whole sites across a slow ramp-up, steady middle and slower late tail. These are simplified planning shapes; actual country and site readiness can vary. A constant profile is possible with ramp-up and tail set to 0. Activation is when a site is ready to recruit, not its site initiation or first patient.
Calendar dates: Month 1 starts at the entered first site activation date. FPI is a separate, optional reference date: it may happen later, and entering it does not alter the activation schedule or recruitment calculation. FSI on the Study Duration page is another distinct milestone.
Recruitment delay: Enter the number of whole model months between activation and a site's first contribution to randomised recruitment. The site contributes an average of half a recruitment month in its first contributing month and full months thereafter. This is a fixed, simplified delay for all sites, not a prediction of an individual site's first patient. Non-recruiting sites are excluded first; remaining sites follow the high/medium/low mix at constant rates.
Whole-patient figures: Calculations retain fractional expected values internally. Cumulative patients are rounded to the nearest whole patient (0.5 rounds up); patients in each month are the difference between consecutive rounded totals. Estimated LPI is the approximate date the expected cumulative value reaches the rounding threshold for the whole-patient target (target minus 0.5), rather than the date the unrounded value reaches the exact target. This aligns the LPI month with the displayed whole-patient total.
Recruitment rates are for randomised patients. Do not deduct screen failure again.
Limitations: The model assumes a chosen activation profile, fixed recruitment performance and a fixed recruitment delay. It does not separately simulate start-up delays, country differences, seasonality, recruitment pauses, screening activity, screen failure, site caps or uncertainty ranges.
Estimated LPI: This is a mathematical expected-value planning estimate, not a guaranteed operational date. The forecast does not model individual sites or patients and is limited to 120 months from first site activation.
Planning estimate only. Validate assumptions against the protocol, individual site feasibility and operational plan. The forecast is limited to 120 months.