Regeneration was the answer for those critics and although it seems to be a departure from the themes of her previous work, Regeneration continues the exploration of trauma (whether experienced by rich or poor) and the recovery from that trauma. Further, 1917 is a revisiting of a historical setting in Liza's England.
Barker had been interested in WWI since reading Owen and Sassoon's poetry as a teenager. She read Rivers' Conflicts and Dreams in her twenties which made her aware of his medical career. Her husband, retired zoology professor David Barker, introduced her to Rivers' nerve regeneration experiments with Dr Henry Head which in turn helped her form the character of Rivers in the novel.