The entertainer, who presented long-running series Surprise, Surprise and Blind Date, said she did not want to "linger" or be a burden on her family.
In an interview on the eve of her 71st birthday, the Liverpudlian reaffirmed her desire to die before health problems affected her.
She said: "Seventy-five is a good age to go, I still think that way.
"I don't want to linger. I don't want to be a burden on anybody. I know 75 is only four years away but I take each day as I find it."
The former singer said she had started to suffer from hearing difficulties and had started to feel stiff in the mornings.
And she said witnessing her mother suffer from a crippling bone disease in her final years had also affected her opinions on her mortality.