Seems obvious enough. We should think of patient input as a kind of form-filling. Items on forms need to be standardized and verifiable. They need to be recognized by collaborating systems.
I guess that in the future large amounts of patient data will be automatically generated and delivered to analysis and workflow systems by personal devices. Various health factors will be monitored and relayed without our ever having to look at the readings, let alone transcribe them into a system.
Patient-input can be presented as patient empowerment. But it's also about downstreaming work. The more the customer does, the less clerking the organization has to do. That's been one side of self-service from the supermarket through the ATM and beyond.
The difference (an difficulty) here may be about nuances. In order to allow a patient to enter, say, symptoms, we'll need to present them with a set of possible symptoms to check. This may encourage people to check more symptoms than they would have done unprompted. It will also mean that the degree to which the symptom itself is causing distress will be masked, meaning that a piece of potentially important data is lost. Call it the light and shadow – the subtleties of human communication that physicians use in the diagnostic process. So maybe patient input will be limited to basic items rather than nuanced ones. EHR