ER use as a function of PCP access in the VA system

From the JGIM:

DESIGN AND PATIENTS:

A longitudinal retrospective study of 627,276 patients receiving primary care from 6,398 primary care providers (PCPs) nationally within the Veterans Health Administration (VHA) in 2009. We tracked weekly changes in PCP-level appointment availability.

MEASUREMENTS:

The number of a PCP's patients who went to the ER in a given week.

RESULTS:

Among all PCPs, being absent from patient care for the week had no effect on whether that PCP's patients used the ER in that week (incident rate ratio (IRR) 0.997, p = 0.70). However, among PCPs who were near-sole providers of care, a PCP's absence for a week or more had a statistically significant effect on ER visits (IRR 1.04, p = 0.01). The percentage of a PCP's weekly appointment slots that were fully booked (booking density) had no significant effect on whether their patients used the ER in that week among all PCPs. However, among near-sole providers of care, a 10-percentage point increase in the booking density changed the IRR of ER visits in that week by 1.005 (p = 0.08) and by 1.006 on weekdays (p = 0.07).

CONCLUSIONS:

Patients' access to their PCP had a small effect on whether those patients used the ER among PCPs whose patients rarely saw another PCP. Among other PCPs, there was no effect of PCP access on ER use. These results suggest that sharing patient-care responsibilities across PCPs may be effective in improving access to care and decreasing unnecessary ER use.

I don't have access to the body of the paper but I wonder if this data set included patients who got frustrated and hopped down the street to the nearest community hospital ER. I bet it didn't.