Medical Homes Fail Yet Another “Natural Experiment”
Three “natural experiments,” three failures. Such is the fate of patient-centered medical homes (PCMH), a well-intentioned but unsuccessful innovation now kept afloat by the interaction of promoter study design sleight-of-hand with customer innumeracy.
By way of review, a natural experiment is an experiment in which the design is outside the control of investigators, yet mimics an experiment. The first two natural experiments below involve applying the intervention across entire states. The third involves a stimulus-response experiment in one specific community.
Statewide Natural Experiments: North Carolina and Vermont
In North Carolina, a statewide Medicaid PCMH was implemented years ago and steadily expanded until most Medicaid recipients belonged to one. There was no reduction in relevant event rates (for ambulatory care-sensitive admissions) and costs increased. While the overall Medicaid budgets were routinely exceeded and that should have caused legislators to realize that something in their PCMH was amiss, Milliman fabricated data to pretend the PCMH program was a success. Milliman got caught making up data (and ignoring other data that quite definitively invalidated its conclusion, and changed their story 180 degrees, a tacit admission that they lied. And shortly thereafter (at least “shortly” by the standards of state government), North Carolina announced that it is abandoning this failed experiment.