She thought her chances of being cast were slim, as she had on bandages following a fall; however, the producer, Geraint Morris, was fascinated by the incident and asked her about her time in the hospital.

In her later years on the show, Duffy battled depression and anxiety, and in 2018, producers created a story arc in which she is diagnosed with vascular dementia.

The first with Registrar Andrew Bower (William Gaminara; Philip Bretherton), and the second with Ryan Johnson (Russell Boulter), a hospital security guard.

[2] Shipton admitted that she was nervous during her first day on set and did not think her Bristol accent sounded right, likening it to "a demented Pam Ayres".

[10] She struggles to deal with the attack and confides in Susie, Megan Roach (Brenda Fricker) and Ewart Plimmer (Bernard Gallagher) who all help her to recover.

[8] Shipton told a BBC reporter Alan Ayres that she had received numerous letters from viewers who had been in similar situations to Duffy.

[17] She arrives to attend Charlie and Baz Hayes' (Julia Watson) wedding, as part of a two-episode special edition of Casualty.

Alongside Shipton former cast members Brenda Fricker, Clive Mantle and Patrick Robinson all reprised their roles as Megan Roach, Mike Barratt and Martin Ashford respectively.

[21] The cast filmed on location for the episodes and Shipton told Steve Clark from Inside Soap that she had to learn all about the new characters and stories because she had avoided watching the show since her departure.

[23] Duffy developed a relationship with hospital security guard Ryan Johnson (Russell Boulter), after he provided her with sympathy over her mother's death.

She explained that the story "holds its own over two episodes and it's really exciting because Duffy's out in Cambodia idealistically setting up a free clinic for people living on the poverty line in a very impoverished country, so that's quite a challenge.

"[12] On-screen Duffy is in the country on a medical mission and Charlie, alongside his colleagues Comfort Jones (Martina Laird), Abs Denham (James Redmond) and Guppy Sandhu (Elyes Gabel), come out to help her.

"[29] When she was in character wearing the hospital uniform, Shipton became emotional and felt that "it was as if time had stood still and within a couple of hours it was business as usual.

Ryan wants to fight for their marriage and he attempts to emotionally blackmail Duffy by bringing her youngest son Paul (Roly Botha) with him.

[35] Shipton told Sarah Ellis of Inside Soap that Duffy is "guilt-tripped" into having a family Christmas, while Charlie is pressuring her to tell Ryan about their relationship.

[34] On the day of the wedding, Duffy has to work due to a staff shortage, while Charlie is in Barry Island, where his stag party took place.

[34] Shipton explained to Inside Soap's Sarah Ellis that Duffy thinks that Charlie has had second thoughts about marrying her, having decided that he has been on his own for all this time, he does not want to change that.

[36] In late September 2018, Sophie Dainty of Digital Spy reported that the character would be the focus of a new mental health storyline that would also affect her marriage to Charlie.

[39] What's on TV's Elaine Reilly observed that Duffy had been "a lonely figure", and Shipton replied that Charlie's recent promotion has left him with more work, so he is spending less time with her and their family.

[40] Shipton struggled to film the affair scenes and the aftermath, in which Duffy lies and keeps the truth from Charlie, calling it "grim, old stuff.

Producer Simon Harper said that stories like Duffy's need to be told "authentically and sensitively, which is why we are always so grateful to fantastic charities like Dementia UK who do incredible work and give us invaluable advice.

[47] The actress added that viewers are invested in Duffy, so her dementia storyline would take a lot of time to play out, and hopefully show what people in real life are going through.

Executive producer Simon Harper thanked Shipton for her contribution to the show and "the British Television Drama landscape", and credited her with creating "a comforting Saturday night icon, the caring, ideal NHS nurse millions grew up with".

[48] As Duffy's dementia storyline progresses, she moves into a residential care home, as Charlie struggles to look after her and deal with her increasing violent behaviour.

A show spokesperson told Inside Soap's Sarah Ellis that it is the last thing the couple wants, as Duffy worked in a home and did not like the conditions.

[54] They said, "Reliable, super-efficient Duffy (Cathy Shipton) featured in the original cast when the medical drama launched in 1986 and is one of Casualty's most iconic and longest-serving characters".

[54] The Western Mail's Madelein Brindley branded Duffy "a stalwart" of Casualty, and wrote "regarded as the mother of A&E she was both caring when needed but not afraid to be strict when necessary.

"[55] Sharon Marshall writing for the Daily Mirror praised Shipton, Thompson and Bleasdale's "sterling performance" during the 30th anniversary episode.

[58] Alison Graham of the Radio Times commented, "The pair have been secretly in love for 30 years, the whole of Casualty's lifetime, so surely they need just to get on with it.

"[59] In 2003, Sarah Moolla of The People criticised the character, saying "Has no home, no job, no money and no pride after being conned by the good-looking, smooth-talking Ryan she'd known for just a few months.