Objective To determine the impact of the GP-led walk-in centre (WIC) in Sheffield (England) on the demand for emergency department (ED) care.

Methods A survey of patients visiting the Sheffield GP WIC was conducted over 3 weeks during September and October 2011. A short, postvisit questionnaire was also sent to those who agreed to determine if the patient had used another NHS service for the same problem. Routine data were obtained from the adult and children's EDs and minor injuries unit in Sheffield, 1 year before and 1 year after the opening of the GP WIC. A linear model of the number of minor daytime attendances (GP type) per month was used to estimate the impact of opening the GP WIC, after controlling for seasonal variation and a linear time trend.

Results A total of 529 patients responded to the survey (response rate 51%). Based on their self-reported intentions, 64 of these patients (53 adults and 11 children) were diverted from going to ED in the 3-week survey period as a result of the establishment of the GP WIC. From this we would have expected around a 26% monthly reduction in GP-type attendances at adult ED, and 7% reduction at children's ED. However, routine data only showed an 8% (95% CI 1% to 16%) reduction at the adult ED. Reductions in GP-type attendances at the children's ED and the minor injury unit at the time of the opening of the GP WIC were also found, but were not statistically significant. The estimated impact on children's ED was a 14% reduction (95% CI −38% to 8%), and for minor injuries unit (MIU) a 4% reduction (95% CI −18 to 9%).

Conclusions There was a statistically significant reduction in GP-type daytime attendances at the adult ED after the opening of the GP WIC. Since this reduction was not mirrored in changes in night-time attendances (when the GP WIC was closed), and our survey responses suggested some people were diverted from going to the ED, it is possible that the opening of the GP WIC caused this reduction.