Most performance advice assumes a full toolkit: find the people who converted, find more like them, follow the ones who did not. In a sensitive health category none of that is available. The interesting question is what a good account looks like when that entire layer is removed.
What is actually left
Four things. The queries you choose to serve on. The creative that decides who self-selects into a click. The page that continues the conversation. And the conversion you send back, which is the only instruction the bidding system receives about what worked.
Three of those four are craft and can be argued about. The fourth is closer to a fact: whatever you count is what the platform will go and find more of. That relationship holds in every account, but in an unrestricted account a good audience can partly compensate for a bad conversion definition. Here nothing compensates.
Why the form fill is worse here than elsewhere
In a category with a two hundred dollar transaction, optimizing to a form fill wastes some money. In a category where a click costs what an elective consultation costs in many markets, and where the treatment is a considered, high-value decision, optimizing to a form fill trains the system on the wrong population with real money and no audience layer to catch the error.
The result is familiar to anyone who has run one of these accounts. Conversions look healthy. The front desk reports that half the enquiries are price-shopping or not remotely qualified. Cost per lead is flat or improving, and the number of people who actually book and turn up is not.
What to count instead
The booked consultation, not the request for one. The consultation attended, not booked. And where the practice can carry it, the treatment. Each step further down is a stronger signal and a smaller number, and the tension between those two is the real design decision, because a conversion event that fires four times a month cannot steer an automated bidding strategy.
The practical compromise most accounts land on is optimizing to the strongest event with enough volume to be learnable, and reporting on the one further down. That is a deliberate choice with a stated reason, which is different from optimizing to a form fill because it was the default.
What this changes about who wins
It moves the advantage away from media sophistication and toward operational plumbing. The practice that can tell its ad platform, within a day or two, which enquiries became booked consultations has an advantage its competitors cannot buy with budget or audience data, because that data is not available to them either.
That is a genuinely unusual competitive situation and it is worth naming. In most verticals the restriction on targeting would be a disadvantage. Here it applies to everyone, which turns the ability to feed real outcomes back into the platform from a best practice into the main axis of competition.
The honest caveat
This is our reading of what follows from the policy, not something Google states. Google publishes the restriction; the strategic consequence is an inference, and a practice with unusually strong creative or an unusually distinctive offer may find those matter more.
What is not an inference is the direction of the constraint. The audience tools are unavailable, the conversion definition is not, and one of those is therefore where the remaining leverage sits.
What this means for an operator
Pick the strongest conversion event your booking volume can actually support, wire it back to the platform, and report on the step below it. In this category that plumbing is the competitive advantage, because the targeting shortcuts are closed to everyone.