Ritical Appraisal of a Piece of Research

I require a critical appraisal of the following paper.

A national scheme for public access defibrillation in England and Wales: Early results
By Colquhoun M. C., Chamberlain D. A., Newcombe R. G., Harris R., Harris S., Peel K., Davies C. S. and Boyle R.
In Resuscitation (2008) 78, 275 280