The first study to use a nationally representative sample to describe after-hours care in the US, released today as a Web First by Health Affairs, demonstrates that emergency room usage is significantly lower when patients have access to after-hours services with their primary care provider.

According to the study by Ann O’Malley of the Center for Studying Health System Change, 30.4 percent of patients with after-hours access to their primary care providers reported emergency room use, compared to 37.7 percent of those lacking after-hours access. Another key finding:  patients with access to after-hours care reported a significantly lower rate of unmet medical need: 6.1 percent versus 13.7 percent of those lacking after-hours access.

The findings come from the 2010 Health Tracking Household Survey of the Center for Studying Health System Change. The total sample included 9,577 respondents, of which 40.2 percent reported that their providers’ practice offered after-hours (evening and weekend) office visits. Of the total sample with a usual primary care provider, 1,470 had attempted to contact their usual provider after-hours within the past twelve months by some means, including phone, electronic or actual visits. Of those trying to access after-hours care, children (through a parent or other adult) had the highest rate of contacting their provider. Less healthy adults and those lacking private insurance reported more difficulty accessing their provider after hours than other respondents.

“Increased support for primary care practices to provide or arrange for accessible after-hours care (by phone, by e-mail, or in person) has the potential to reduce rates of emergency department use,” O’Malley concludes. “When primary care providers deliver more accessible care after hours and avoid potentially unnecessary emergency department visits, decreasing overall costs to the system, the current fee-for-service system does not reward them. It is hoped that future payment reform under patient-centered medical homes and bundled payments may begin to address these issues.”