Do you have evidence of this part specifically? Because the Oregon Experiment found no improvement in health outcomes in a large randomized trial of low-income recipients of Medicaid. (Partly because their health was generally good in the first place.)
https://en.wikipedia.org/wiki/Oregon_Medicaid_health_experim...
While they credit the ACA with saving their life, had we had some form of socialized medicine from the start, this likely would've been caught much earlier, treated much more easily, and with significantly less long term effects.
I couldn't easily find studies on preventative care leading to better outcomes, but given how many diseases (like cancer for example) can go from easily treatable to a catastrophic nightmare depending on how early they are detected, I find it hard to believe that easy, cheap (or free) access screenings would have no effect on outcomes, though I realize how treacherous it can be to rely on instinct instead of data.
It did show an improvement is psychological outcomes, I presume due to peace of mind, because their wasn’t a corresponding increase in psychiatric medication.
It is part of large complicated model. If it was their entire model they wouldn't be operating medical offices and hospitals. It is the whole package that helps them control costs.
From this, I derived the argument that routine checkups are a *major* component of Kaiser’s system, to the point that, given the flow of discussion, I felt it appropriate to call it “their whole model”. I’m sorry my hyperbole was too far.
Well that and with Kaiser it's a lot easier to tell who is in network (they never commingle in and out of network care).