[4][5] Brock and Unwin devised the serial after being inspired by the "comedy and heroics" of life in the National Health Service (NHS) and tackled a string of controversial topics through the show.
[1] A spin-off series, Holby City, began airing from 1999 and follows patients' stories after they are transferred to the hospital's surgical wards.
[7] A police procedural spin-off, HolbyBlue, began airing from 8 May 2007, running for two series before being cancelled due to poor viewing figures.
[11] Additionally, Casualty features a number of guest artists in each episode as well as recurring characters who appear in story arcs.
In 2004, casting directors hired Susan Cookson for the regular role of Maggie Coldwell after a recurring part as anaesthetist Julie Day between 1998 and 2000.