[Cost unit accounting of strabismus surgery at a university eye hospital]

Strabismus surgery is frequently carried out in university centers. The aim of this work was to calculate the costs of strabismus surgery at a university hospital and to assess the remuneration of costs for outpatient procedures.

Of all strabismus surgeries at the Hanover Medical School in the years 2018 and 2019, relevant surgical data, such as patient age, number of muscles operated on, incision to suture time, attendance time of the surgeons and anesthetists as well as the nursing staff, were evaluated based on the clinics own information system. During this process, the costs for personnel, material, room rental charges and overheads were computed applying cost unit accounting.

A total of 302 operations (inpatient proportion 92.1%) were carried out in most cases with the patient under general anesthesia. The mean patient age was 31 years (median 26 years), with 33 patients being children under 6 years of age. On average 1.84 muscles were treated per intervention. The mean incision to suture time was 51.5 min, mean anesthesia time was 85 min, the attendance time of surgical as well as anesthesia nursing staff each accounted for 104 min, the additional time in the postanesthesia care unit added 66 min. Average personnel costs originating from the overall process amounted to 642.14 €, with the addition of 109.23 € for material and medication (surgery and anesthesia) and costs for cleaning and room rental (including overheads) of 178.71 €. Therefore, the overall costs of an average strabismus surgery in our collective added up to 930.08 € (minimum 491.01 €, maximum 1729.29 €). Cost accounting of subgroups yielded substantially higher costs for anesthesia in children as well as for higher numbers of muscles operated on due to different treatment duration (37 min for 1 muscle to 72 min for 3 muscles) and anesthesia time, especially in children <6 years of age (on average 22 min longer than adults and children >5 years; the differences being 11 min for 1 muscle, 25 min for 2 muscles and 30 min for 3 or more muscles). The pure costs of a strabismus surgery at this clinic seem on average to exceed the revenues for strabismus surgery in the outpatient sector calculated by the German uniform evaluation benchmark (EBM) by about a factor of 2.

It could be shown that the purely economically calculated costs for strabismus surgery at a university clinic are significantly higher than the revenues achieved in the outpatient sector according to paragraph 115b, section 1, of the Social Security Act V (SGB V). Under these circumstances, such operations cannot be performed in a cost-effective manner.