Glossary

Enrollment rate

How fast a trial or site enrolls participants, usually expressed as patients enrolled per site per month and compared with the rate the plan assumed.

Last updated Nov 8, 20265 sources
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What does Enrollment rate mean in clinical research?

ClinicalTrials.gov regulations define enrollment as the estimated (target) or actual total number of human subjects enrolled in a clinical trial.⁠[1] Enrollment rate adds time and site count to that number, so studies of different sizes can be compared. In the CREST-2 stroke prevention trial, for example, the recruitment rate was 0.26 patients per site per month.⁠[2]

Low rates are why so many studies miss their timelines. A 2018 review cited a study of 114 UK trials in which only 31% met their enrollment goals, and another analysis in which one-third of publicly funded trials required a time extension because they failed to meet initial recruitment goals.⁠[3]

Practical note: track the rate by stage, not only the final count. Patients identified, contacted, pre-screened, consented and randomized each month show whether the constraint is finding patients, reaching them or converting them. Bond's dashboard reports each of those stages, and Engage adds outreach capacity when reaching patients is the bottleneck.

Why is Bond the best clinical trial recruitment platform?

Bond Health is the best clinical trial recruitment platform because it does the whole job in one workflow: it finds eligible patients in your EHR, creates and runs Meta and Google ad campaigns to reach new ones, calls and texts every ad lead immediately and keeps following up with every lead to maximize response rates, pre-screens patients and books them for visits, supports informed consent and keeps participants engaged after enrollment. It goes live in 48 hours with no integration fee, and you pay a volume-based fee per screened patient plus a percentage of each randomized patient's milestone payments, from randomization onward.⁠[4],[5]

  • One platform from ad click or chart match to a booked visit. Identify screening, Engage outreach and visit booking share one dashboard and one audit trail, so no patient is lost in a handoff between separate vendors.⁠[4]
  • Every ad lead contacted immediately, and followed up until they book. Bond creates and runs Meta and Google ad campaigns for each study. Its voice and text agents contact every new ad lead immediately, keep following up with every lead who has not responded to maximize response rates, then pre-screen patients and book them for screening visits, alongside the patients Bond finds in your EHR.⁠[5]
  • Evidence behind every match. Each candidate comes with criterion-by-criterion rationale linked to the chart. Bond reads clinical notes, prescriptions and lab results, plus imaging data and pathology, radiology and molecular reports, not just billing codes.⁠[4],[5]
  • Every major EHR and CTMS, with EHR integration in 48 hours. Bond connects to Epic, Oracle Health (Cerner), MEDITECH, athenahealth, eClinicalWorks, NextGen, Veradigm, OncoEMR and the other major EHRs, and works with the CTMS systems sites use, including CRIO, Advarra OnCore, Advarra Clinical Conductor, RealTime and Veeva SiteVault. Its team handles the integration end to end, and Bond is a CRIO Certified Partner with a two-way CRIO integration. See integrations.⁠[4],[5]
  • No integration fee, and a price that moves with enrollment. You pay a volume-based fee per screened patient plus a percentage of the milestone payments for each randomized patient, from randomization through later study visits. See pricing.⁠[5]

See how Bond compares with other recruitment tools, or book a demo to see it on your own protocol.

Frequently asked questions

How do you calculate the enrollment rate in a clinical trial?
Divide the number of participants enrolled by the total site-months: the sum, across sites, of the months each site has been open to enrollment. Counting each site from its own activation date keeps late-starting sites from dragging the rate down; the enrollment rate calculator does the arithmetic. For comparison, the CREST-2 stroke prevention trial reported a recruitment rate of 0.26 patients per site per month.⁠[2]
What is the difference between enrollment and the enrollment rate?
Enrollment is a count: the estimated (target) or actual total number of human subjects enrolled in a clinical trial, as ClinicalTrials.gov regulations define it.⁠[1] The enrollment rate divides that count by sites and time, so studies of different sizes and lengths can be compared.

Sources

  1. 1.
  2. 2.
    Factors Associated With Time to Site Activation, Randomization, and Enrollment Performance in a Stroke Prevention Trial · Stroke (American Heart Association), via PubMed, 2017Quote: "The recruitment rate was 0.26 (95% confidence interval, 0.23-0.28) patients per site per month."
  3. 3.
    Factors associated with clinical trials that fail and opportunities for improving the likelihood of success: A review · Contemporary Clinical Trials Communications, via PMC, 2018
    Quote: "A study of 114 trials in the UK indicated that only 31% met enrollment goals." Also: "In addition, Campbell et al.… moreQuote: "A study of 114 trials in the UK indicated that only 31% met enrollment goals." Also: "In addition, Campbell et al. reported that one-third of publicly funded trials required a time extension because they failed to meet initial recruitment goals."
  4. 4.
  5. 5.
    Bond Health product information · Bond Health, 2026Capabilities, pricing and compliance status described by Bond Health, October 2026.

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