This is a Physician in the Loop special topic.

Route, don't write

AI that drafts replies to patients has not reliably saved doctors time. Health systems should first use AI to sort the inbox, and draft clinical replies only where audits show a gain.

AI drafts of replies to patients take doctors longest to correct when the message most needs a doctor's judgment. A study published at the end of August examined how more than a thousand physicians at UC San Diego Health edited replies drafted for them by software in the health system's Epic record. Each reply was timed from the moment a doctor began it until it was sent, and every kind of change the doctors made was associated with a slower reply. After allowing for how complex the message was, the largest increases in time came with changes that explained a scan or a laboratory result, or that clarified or ruled out a diagnosis.

The commonest edit, nearly two in five by the study's count, involved booking or moving an appointment, and because such administrative edits were so frequent, they added the most work across the health system. The first job for AI in the inbox should be routing: sending requests for appointments, refills and forms to the staff who handle them, and lifting urgent symptoms to the top. Drafts of clinical replies should be switched on only where a local audit shows they save time without adding errors.

Earlier studies in clinics found little or no saving of time. A randomized quality improvement study at UC San Diego, published in 2024, found that the drafts did not shorten the time primary care doctors spent replying and came with longer reading times and longer replies. At Stanford, drafts written for primary care and gastroenterology clinicians during a five-week pilot in 2023 did not save them time, though in surveys before and after the pilot, answered by fewer than half of them, the clinicians reported a lighter mental load and less exhaustion. Where drafts did save time, the gain was small: at Children's Hospital of Philadelphia, clinicians saved about three seconds a message. Drafts also make mistakes. In an experiment at Mass General Brigham, OpenAI's GPT-4 invented 100 questions from patients with cancer and drafted replies to them; radiation oncologists answered the questions themselves and then edited the drafts. In about one in 14 of their assessments, the doctors judged that a draft sent unedited risked severe harm, and in one, death.

Routing has been studied on a far larger scale. In 2022 Kaiser Permanente in Northern California began using software that labels patients' messages by topic and sorts them to the right staff. In five months of 2023, its regional team resolved nearly a third of almost 5 million messages before they reached the physician they were addressed to, most of them through medical assistants and telephone staff. The study, by the group's own researchers, was a quality improvement report.

Kaiser's Southern California medical group built a tool that categorizes messages by topic and flags urgent cases as top priorities. In clinics that adopted it, the median wait before a clinician first read a message the tool marked urgent fell from about 22 hours to 5; in similar clinics without the tool, it fell from about 18 hours to 15. Both comparisons used samples of messages the tool itself had marked urgent, so they say nothing about urgent messages it missed. The study was the medical group's evaluation of its own tool. None of these studies is a randomized trial: they are a count of messages handled and before-and-after comparisons. Routing first is a reasoned bet, and it should be tested as one.

Defenders of AI drafting reply that time is the wrong measure. Doctors like the drafts: Stanford's clinicians reported less exhaustion, and the senior author of UC San Diego's 2024 study said that physicians "appreciated the help, which lowered cognitive burden." And routing carries a risk that drafting does not, since a person reads every draft before it is sent, while software that sends a message about chest pain to a scheduler acts where no doctor looks. The relief is real, but doctors reported it themselves, while the cost in time was measured, and it holds only while they check each draft as closely as a reply of their own. Nor is misjudged urgency a hazard of routing alone: most of the harmful drafts in the Mass General Brigham experiment misjudged or misstated how urgent the problem was.

Health systems, and the physicians on the committees that run their inboxes, should put routing first; Kaiser's two medical groups show it can run at scale. No router should be the only safeguard: where it hands messages to schedulers, a person should read each one, with a rule and a direct line for passing any symptom to a nurse at once. The router should be set, as Kaiser's in Southern California was, to flag too much rather than too little, and a clinician should check a sample of its choices each month and report to the medical staff how many urgent messages went to the wrong desk.

Drafting should come second, switched on for one kind of message at a time and kept only where an audit shows a gain. Replies about scans, test results and diagnoses, which took UC San Diego's doctors longest to fix, should be the last to get drafts. The order itself should be tested, by switching the features on clinic by clinic in random order and counting minutes, errors and missed urgent messages, with the results published.

At UC San Diego the commonest change doctors made to a draft concerned an appointment, and the costliest concerned what a scan showed. Software that sends requests for appointments to the people who book them could leave doctors more time to explain the scans, which is where a patient most needs a doctor's own words.

This special topic was read by an AI voice. Its sources are linked at physicianintheloop.org.