The Oxbridge doctors' white coats were actually yellow, to prevent on-screen camera flare. As the show was made and shown in monochrome viewers remained none the wiser.
Although Plato's Stepchildren (1968)(#3.10) of Star Trek (1966) is commonly held to have featured television's first interracial kiss, that was only the case on U.S. television. Episode #1.724 (1964)(#1.724), of this show, broadcast in July 17, 1964, previously featured such a scene, when a long-burning romance blossomed between Louise Mahler (Joan Hooley) and Giles Farmer (John White). Some sequences were carefully toned down before transmission.
Patient deaths were strictly limited to five per year, later reduced to just two.
The closing signature tune on this show, "Silks and Satins" by Peter Yorke, was a stock library track and so able to be used by any production company. As a result of this, the piece was often heard on Prisoner (1979) as an "old film theme" when the women of Wentworth Detention Centre were watching television.
Much of the series no longer exists in any form. The earliest known surviving installments are episodes 235 and 236, from May 1959, held by the U.K.'s National Film and Television Archives.