Previously called the Whitbread award, the prize is worth Â£30,000 and aims to honour outstanding books by authors based in the UK and Ireland.
The winner will be one of those that won the prize's individual awards - for novel, first novel, biography, poetry and children's book - on 5 January.
Nick Higham spoke to four of the winning authors for the BBC News channel's Meet the Authors strand.
The fifth, Ali Smith, declined to be interviewed, though she did speak to the Costa awards' organisers.
Edwards, a teacher from South Wales, won the Costa poetry prize for My Family and Other Superheroes, which features comedic verse about Evel Knievel, Sophia Loren and a recalcitrant hippo.
The poet revealed to Higham that some of his work had been inspired by episodes of animated sitcom The Simpsons, but admitted he had never taught his students about his poems.
Former bookbinder Healey won the debut novel prize for Elizabeth Is Missing, about a woman in her 80s who tries to solve the mystery of her sister's disappearance while struggling with memory loss.
The author, who is also a budding animator, told Higham she had been thinking about dementia "for a while" and revealed she deliberately wrote her novel out of sequence.
Poet and historian Macdonald won the biography prize for H is for Hawk, a memoir about how becoming a falconer helped her come to terms with her father's death.
Macdonald, whose book also won the Samuel Johnson Prize for Non-Fiction, told Higham she had had an "astonishing" year and said she had often been "brought to tears" by her readers' own stories of grief and bereavement.
Journalist and broadcaster Saunders won the Costa children's prize for Five Children and the Western Front, a reworking of E Nesbit's 1902 children's classic Five Children and It.
"When you add the First World War it becomes a different story," she told Higham, insisting she had not tried to "consciously ape" Nesbit's writing style.
Scottish author Smith, a previous recipient of the Whitbread novel of the year prize, was made a CBE in the New Year's Honours shortly before receiving the Costa novel award for How To Be Both.
The book tells of a grieving 15-year-old girl in the present day and Francesco del Cossa, a long-forgotten 15th Century Renaissance artist.
One of five books will be named Costa Book of the Year on 27 January.