Estimation of Patient Accrual Rates in Clinical Trials Based on Routine Data from Hospital Information Systems

Background: Delayed patient recruitment is a common problem in clinical trials. According to the literature, only about a third of medical research studies recruit their planned number of patients within the time originally specified. Objectives: To provide a method to estimate patient accrual rates in clinical trials based on routine data from hospital information systems (HIS). Methods: Based on inclusion and exclusion criteria for each trial, a specific HIS report is generated to list potential trial subjects. Because not all information relevant for assessment of patient eligibility is available as coded HIS items, a sample of this patient list is reviewed manually by study physicians. Proportions of matching and non-matching patients are analyzed with a Chi-squared test. An estimation formula for patient accrual rate is derived from this data. Results: The method is demonstrated with two datasets from cardiology and oncology. HIS reports should account for previous disease episodes and eliminate duplicate persons. Conclusion: HIS data in combination with manual chart review can be applied to estimate patient recruitment for clinical trials.