Patients who had access to GP surgeries with longer opening times in evenings and at weekend visited accident and emergence departments far fewer times than those who did not have similar access to primary care.

The findings of the report published in PLOS Medicine have implications for the British Government's desire to implement a seven-day NHS service. Funding given to GP surgeries to extend their hours may reduce demand on emergency hospital service especially at the weekend - but the cost of doing so may outweigh the benefits.

The study analysed data from nearly three million patients from 525 GP surgeries in North West England. NHS England (Greater Manchester) provided £3.1 million to enable 56 GP surgeries to open longer in the evening and at the weekend during 2014. These 56 surgeries had 346.024 patients in total, while the wider patient population in the non-funded 469 surgeries was 2,596,330.

The research team looked at total emergency department visits by each cohort; the extended-access GP surgeries had a 26.4 percent relative reduction in patient-initiated emergency department visits for minor problems - equating to nearly 11,000 fewer visits. The cost saved by those fewer admissions was only £767,976 - less than a quarter of the extra funds allocated to surgeries to extend their hours.

However, the study solely focused on emergency department admissions, and did not collect any data on health outcomes - either from a post-A&E visit or from seeing a GP in extended hours. Therefore the analysis does not take into consideration the potential benefits to those patients using additional appointments who would not have visited emergency departments otherwise.

William Whittaker, Research Fellow in Health Economics at The University of Manchester, was the lead author of the report and notes caution for 7-day services if solely aimed at reducing emergency department visits.

"There's a need for evidence that 7-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.

"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," Mr Whittaker concluded.

Article: Associations between Extending Access to Primary Care and Emergency Department Visits: A Difference-In-Differences Analysis, William Whittaker , Laura Anselmi, Soren Rud Kristensen, Yiu-Shing Lau, Simon Bailey, Peter Bower, Katherine Checkland, Rebecca Elvey, Katy Rothwell, Jonathan Stokes, Damian Hodgson, PLoS Medicine, doi: 10.1371/journal.pmed.1002113, 6 September 2016.