I can't attest to how schools outside of CA screen applicants, and I have no idea how any school screens applicants for interviews, however its a well known fact that med school's under the University of CA system screens GPA/MCAT for secondary applications.
None of the UC med school's will ever say it flat out. Here at UCDSOM, they say that they look at your "complete application" (e.g., the primary app). There is much truth behind this, but given the statistics associated with UC med schools, it also fails to mention their pre-screening process. The closest any UC has officially come to implying an actual screening process would be UCSF. On their website (FAQ's), they state that anyone with less than a 3.2 GPA is not considered competative, BUT encourage non-trads to apply. Over the years, after talking to various adcoms, attended many pre-AMSA meetings, we've come to the conclusion that UC's tend to screen out people who have less than a 3.0-3.2 GPA, and an MCAT score of 24-26.
The statistics implies a skewed relationship. This is why MSAR uses medians for its national statistics, and the statistics for each individual school. Medians are NOT affected by extreme values. So its not statistically appropriate to imply that a low median GPA/MCAT at one school implies people with low GPA's getting in. For example, if the median GPA of matriculants was a 3.2, then it may not mean that people with <3.2 got in. It could've meant that half the people that got in had 3.2's! Who knows! Without the range, we may never know. As Nasrudin said though, the whole low GPA issue is moot for non-trads who have shown improvement. For instance, I will have a PhD. This doesn't guarantee me anything, but they can't treat me like an undergrad either. It will be dealt with on a case-by-case basis. All we can do is to continue improving our stats, and hope for the best. Anyway, here's some more details about the application process....
Back in 2001, I was fortunate enough to talk to a student adcom from UCSF which ultimately made things a bit more clearer. Your primary application can fall into 1 of 3 piles. (1) Gets a secondary application, (2) rejected pre-secondary application, (3) maybe get a secondary (after a closer look). Piles 1 and 2 are easy to figure out. You either make the GPA/MCAT criteria or not. Pile 3 is the interesting one, and this is definitely a VERY small pile. You get into this pile if there is something that the adcoms feel was important to diserve additional consideration despite not meeting the GPA/MCAT criteria. Such as working to support your family, significant improvement, etc.
Now one should take this 3rd pile as a grain of salt. My PI who is a UCSF alumnus clarified the process even further. The whole process takes into account foure items: (1) GPA/MCAT, (2) Personal Statement, (3) Letters of Recommendations, and (4) Personal Interviews. They are weighted differently, and at the time of him attending UCSF, it was on a 6 point basis. GPA/MCAT = 1/6, PS = 1/6, LOR = 2/6 and Interviews = 2/6. Your GPA/MCAT lose most of its "weight" after interviews, and a lot is dependent on your LORs and interviews. The irony is that you'd never reach the LOR/Interview stage (secondary/post-secondary) without jumping through the GPA/MCAT cut-off.
For me, I'm just focused on surviving the screening process at the UC's which implies that I will have many years of significant GPA improvement since undergrad. I think it will be about 5 years worth of additional undergrad work post-bacc😉 while earning a PhD. Therefore in theory, it should show my PRESENT capacity to do well, dedication to the profession, and 5 years of additional EC's and what not. If you ask me, I still think I'll get denied at UC's though..haha.