Extending primary care practice hours at night and over the weekend may reduce emergency department (ED) visits in patients with minor injuries and illnesses, according to a new study in PLOS Medicine.

As with general practitioners in the United States and other countries, GPs in the United Kingdom provide primary care from 8:30 a.m. to 6:30 p.m. Patients needing care outside of these hours often turn to emergency departments for care.

The United States faces similar trends of ED use: 48 percent of respondents to the 2011 National Health Interview Survey (NHIS) said they went to the ED instead of to their primary physician because the doctor's office was not open.

Researchers from the University of Manchester wanted to find out how extending primary care hours might influence visit to the ED, so they turned to information routinely gathered in the U.K. According to statistics presented by the study, 26.5 percent of people in England visit the ED after trying to go to their primary care provider.

In hopes of lowering costs associated with ED visits, England's National Health Service England appropriated £3.1 million to 56 primary care practices located in the Greater Manchester area, which enabled the practices to extend urgent and routine appointments hours into the evening and over the weekend during 2014.

The researchers used data gathered from 2011 to 2014 to compare changes in the number of ED visits from the 56 extended care practices to the patients visiting from 469 practices that provided routine access during normal doctor office hours. In all, 346,024 patients visited the 56 extended-access practices and 2,596,330 patients visited the 469 practices providing routine care.

With 10,933 fewer ED visits per year, the patients registered with extended-hours practices were 26.4 percent less likely to go to the ED for minor issues compared with patients registered with practices offering routine access. This means that, for every three additional primary care appointments added to a practice's schedule, one ED visit was avoided.

The scientists did not have enough data to analyze cost-effectiveness formally, however, and did not gather information on patient outcomes. As a result, the research does not consider other potential benefits to patients who would have not visited the emergency department otherwise.

Lead author of the study William Whittaker, of the University of Manchester, cautions against offering seven-day services if the only purpose is to reduce ED visits.

"There's a need for evidence that seven-day primary care has benefits to patients as on the basis of emergency department savings alone, extending primary care is unlikely to be cost-effective," says Whittaker. "Our study suggests that extending opening hours in primary care may be a useful addition to policies aiming to reduce pressures on hospital services, potentially reducing patient-initiated use of the emergency department for minor problems — but at a significant cost."