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Sample size calculation for count data in comparative clinical trials with nonuniform patient accrual and early
Huiling Li1, Lin Wang, Lynn Wei
1a Department of Statistical Science , Forest Research Institute, Harborside Financial Center - Plaza V , Jersey City , New Jersey , USA.
Abstract:
In clinical trials with counts of recurrent event data, it is often of particular interest to test whether the experimental treatment reduces the event rate in comparison with a control. The sample size calculation for such a trial often assumes fixed follow-up time for each patient. In many trials, however, we follow all patients for a predetermined follow-up time after the end of the accrual period, in which case the follow-up time is variable. This article provides methods for sample size calculation for clinical trials with ordinary Poisson count data and variable follow-up time allowing for nonuniform accrual and early dropouts. We also generalize the sample size formula to count data with overdispersion.
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