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Full-Text Articles in Physical Sciences and Mathematics

On The Existence Of Constant Accrual Rates In Clinical Trials And Direction For Future Research, Byron J. Gajewski, Stephen D. Simon, Susan E. Carslon Jun 2012

On The Existence Of Constant Accrual Rates In Clinical Trials And Direction For Future Research, Byron J. Gajewski, Stephen D. Simon, Susan E. Carslon

Byron J Gajewski

Many clinical trials fall short of their accrual goals. This can be avoided with accurate accrual prediction tools. Past researchers provide important methodological alternative models for predicting accrual in clinical trials. One model allows for slow accrual at the start of the study, which eventually reaches a threshold. A simpler model assumes a constant rate of accrual. A comparison has been attempted but we wish to point out some important considerations when comparing these two models. In fact, we can examine the reasonableness of a constant accrual assumption (simpler model) which had data 239 days into a three- year study. …


Data Envelopment Analysis In The Presence Of Measurement Error: Case Study From The National Database Of Nursing Quality Indicators (Ndnqi), Byron J. Gajewski, Robert Lee, Nancy Dunton Jan 2012

Data Envelopment Analysis In The Presence Of Measurement Error: Case Study From The National Database Of Nursing Quality Indicators (Ndnqi), Byron J. Gajewski, Robert Lee, Nancy Dunton

Byron J Gajewski

Data envelopment analysis (DEA) is the most commonly used approach for evaluating healthcare efficiency [B. Hollingsworth, The measurement of efficiency and productivity of health care delivery. Health Economics 17(10) (2008), pp. 1107–1128], but a long-standing concern is that DEA assumes that data are measured without error. This is quite unlikely, and DEA and other efficiency analysis techniques may yield biased efficiency estimates if it is not realized [B.J. Gajewski, R. Lee, M. Bott, U. Piamjariyakul, and R.L. Taunton, On estimating the distribution of data envelopment analysis efficiency scores: an application to nursing homes’ care planning process. Journal of Applied Statistics …