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. 2005 Mar 30:5:11.
doi: 10.1186/1471-2288-5-11.

Practical considerations for estimating clinical trial accrual periods: application to a multi-center effectiveness study

Rickey E Carter  1 , Susan C Sonne, Kathleen T Brady
Affiliations

Practical considerations for estimating clinical trial accrual periods: application to a multi-center effectiveness study

Rickey E Carter et al. BMC Med Res Methodol. .

Abstract

Background: Adequate participant recruitment is vital to the conduct of a clinical trial. Projected recruitment rates are often over-estimated, and the time to recruit the target population (accrual period) is often under-estimated.

Methods: This report illustrates three approaches to estimating the accrual period and applies the methods to a multi-center, randomized, placebo controlled trial undergoing development.

Results: Incorporating known sources of accrual variation can yield a more justified estimate of the accrual period. Simulation studies can be incorporated into a clinical trial's planning phase to provide estimates for key accrual summaries including the mean and standard deviation of the accrual period.

Conclusion: The accrual period of a clinical trial should be carefully considered, and the allocation of sufficient time for participant recruitment is a fundamental aspect of planning a clinical trial.

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Figures

Figure 1
Figure 1
Expected accrual rate by month assuming an April 2005 start date.
See this image and copyright information in PMC

References

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