Robin Cook and the Source Novel (Coma) Coma

Cook studied bestsellers before writing Coma

Robin Cook was a physician -- a graduate of Columbia University College of Physicians and Surgeons with postgraduate training at Harvard -- who decided to write a novel. His first book failed. For his second, he studied what made bestsellers work, picking apart Jaws and Love Story as models: books by unknown writers who achieved instant success. He reverse-engineered their structures and applied the formula to a medical setting he knew from the inside. The result was Coma, published by Signet in 1977, which became the number-one thriller on the New York Times Book Review list and sold its paperback rights for $800,000. (wikipedia, wikipedia-novel)

The novel's paranoia came from inside the profession

Cook and Crichton had met when Crichton was doing post-doctoral work in biology at La Jolla's Salk Institute and Cook was a Navy physician stationed in San Diego. Their shared medical backgrounds meant the material's procedural detail was not researched but remembered. Cook framed his motive as educational:

"I sought to educate the public about how the system works." — Robin Cook, quoted in MovieWeb (2023)

He also insisted he did not believe any profession was beyond scrutiny, and that he advocated organ donation even as his novel made people afraid of it. The paradox defined his career: he spent decades writing thrillers that exposed medical malfeasance while maintaining that the profession was fundamentally trustworthy. (movieweb)

The novel gave Susan Wheeler a more explicitly feminist motivation

The key difference between Cook's novel and Crichton's screenplay is structural. In the novel, Susan Wheeler is a medical student, not a resident, and her investigation is driven partly by a desire to prove herself in a male-dominated field. Crichton's screenplay roots her investigation more squarely in personal loss -- Nancy Greenly is her close friend, and the emotional catalyst is grief transformed into suspicion. One reviewer summarized the shift: "the overall sense of paranoia that pervades the book is very much intact in Crichton's screen treatment," but the feminist motivation that drives the novel's Susan is folded into the film's institutional dynamics rather than stated outright. (motionstatereview)

Crichton found adapting someone else's work liberating:

"I found it much easier to adapt someone else's work than to adapt my own... Writing original screenplays is more fun. But Coma to me is very interesting... it's the kind of story that I like, because it's based on a premise that is not impossible." — Michael Crichton, MichaelCrichton.com (n.d.)

Cook's novel launched the medical thriller as a publishing genre

Before Coma, medical settings appeared in fiction but not as a genre category. Cook's commercial success proved the category bankable. He went on to publish more than thirty medical thrillers -- Brain (1981), Outbreak (1987), Vital Signs (1991), Contagion (1995) -- establishing a template that other writers would follow. The film's $30 million gross confirmed that the genre worked on screen as well as on the page, and the cycle of medical-thriller adaptations that followed -- including the film version of Cook's own Outbreak precursor material and the long tail of hospital-conspiracy narratives through the 1990s -- traces back to Coma's proof of concept. (wikipedia)

The real-world consequences were severe

The novel's premise -- that a hospital could deliberately render patients brain-dead to harvest their organs -- hit the public at a moment when organ transplantation was still poorly understood and the medical profession's authority was already shaken by post-Watergate institutional distrust. The film amplified the damage. Organ donation rates reportedly declined 50 to 60 percent in some cities after the 1978 release. Cook maintained his position: he advocated donation, but he did not believe doctors should be exempt from scrutiny. (movieweb)