8 Sequential designs

stop trial early: sequential analyses

sample path: plot efficient score $Z$ vs. Fisher’s information $V$

triangular test: control of error rates of type I and II

Christmas tree: correct for gaps between interim looks.

Further reading:

• •

  Whitehead J (1997) The design and analysis of sequential clinical trials. Wiley, 2nd edition.

• •

  Jennison, C., & Turnbull, B. W. (1999). Group sequential methods with applications to clinical trials. Chapman and Hall/CRC.

Patients

women attending for outpatient termination of pregnancy.

Objective

Does the experimental anaesthetic reduce the incidence of serious nausea compared with the control technique? ($\to$ binary data).

Statistics

$Z={\displaystyle \frac{n_E{S}_C-n_C{S}_E}{n}}$ and $V={\displaystyle \frac{n_E{n}_{C}SF}{n^3}}$.

Unnumbered Figure: Link