Star Neil Patrick Harris reportedly drew inspiration from watching Robert Young in "Marcus Welby, M.D." (1969). Learning that Young was ill and pondering death, Harris visited Young with tapes of "Doogie Howser" and helped cheer him up.
Steven Bochco stated in his interview on the Season One DVD that had he been able to finish the series and write a "final" season (as opposed to ABC's abrupt cancellation of the show in its fourth season), he would have had a season long story arc in which Doogie becomes disillusioned with medicine and in the end, becomes a writer.
Steven Bochco partially modeled the character of Doogie Howser after his father who had been a child prodigy himself as a violinist.
In 2008, "Doogie Howser, M.D." (1989) star Neil Patrick Harris appeared in TV and print ads for Old Spice deodorant spoofing his Doogie Howser character (he said that he could recommend the product as a "former make-believe doctor" and because he "used to be a doctor for pretend;" he also tried to use a stethoscope on a patient's nose instead of his chest).
Doogie was born September 21, 1973. His sixteenth birthday, which is celebrated in the pilot episode, is only two days after the pilot aired (September 19, 1989).