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Table 2 Sample size calculations

From: The management of acute venous thromboembolism in clinical practice – study rationale and protocol of the European PREFER in VTE Registry

  Assumed rate of AE leading to, or prolonging, hospitalization Assumed absolute precision (relative precision) Sample size (without drop-outs) Sample size (including drop-outs)
DVT 0.123 0.031 (± 25%) 432 540
PE 0.179 0.045 (± 25%) 279 349
  1. Sample size (for each region) for the assumed rate of AEs leading to, or prolonging hospitalization 0.123 (DVT) and 0.179 (PE) in order to achieve an absolute precision of 0.031 (DVT) and 0.045 (PE) for a two-sided 95% CI. (Based on normal approximation, calculated by nQuery Advisor® 7.0.). AE, adverse event