Background Emergency departments (EDs) are increasingly overcrowded by walk-in patients. However, little is known about health-economic consequences resulting from long waiting times and inefficient use of specialised resources. We have evaluated a quality improvement project of a Swiss urban hospital: In 2009, a triage system and a hospital-associated primary care unit with General Practitioners (H-GP-unit) were implemented beside the conventional hospital ED. This resulted in improved medical service provision with reduced process times and more efficient diagnostic testing. We now report on health-economic effects.

Methods From the hospital perspective, we performed a cost comparison study analysing treatment costs in the old emergency model (ED, only) versus treatment costs in the new emergency model (triage plus ED plus H-GP-unit) from 2007 to 2011. Hospital cost accounting data were applied. All consecutive outpatient emergency contacts were included for 1 month in each follow-up year.

Results The annual number of outpatient emergency contacts increased from n=10 440 (2007; baseline) to n=16 326 (2011; after intervention), reflecting a general trend. In 2007, mean treatment costs per outpatient were €358 (95% CI 342 to 375). Until 2011, costs increased in the ED (€423 (396 to 454)), but considerably decreased in the H-GP-unit (€235 (221 to 250)). Compared with 2007, the annual local budget spent for treatment of 16 326 patients in 2011 showed cost reductions of €417 600 (27 200 to 493 600) after adjustment for increasing patient numbers.

Conclusions From the health-economic point of view, our new service model shows ‘dominance’ over the old model: While quality of service provision improved (reduced waiting times; more efficient resource use in the H-GP-unit), treatment costs sustainably decreased against the secular trend of increase.