03 Large regional differences in elective medical interventions in Switzerland

Based on the medical hospital statistics, Swiss hospital regions were formed using epidemiological methods. A statistical analysis then was performed to see how the rates of 15 elective interventions differ on a regional basis and over time. Recent and controversial interventions such as closure of the aperture between the right and left upper chambers of the heart following a stroke were also included. These data were linked to other hospital data and data from the Swiss Medical Society. Regression models were used to investigate the influence of socio-economic, health-related, regional, and supply-driven factors on regional differences in the performance of elective interventions. Larger differences, especially for controversial interventions, indicated a possible overuse.

About 25 per cent of Swiss health-related costs are incurred by elective interventions, i.e. operations that are not absolutely necessary. Regarding the frequency and technique of certain interventions, such as cement injections in vertebral fractures, knee and hip replacement or certain invasive procedures involving the heart, there are large regional differences. The differences indicate that it is probably not primarily medical reasons but factors such as the patient's wishes or the doctor’s personal preference that are decisive for the interventions. The introduction of flat-rate payments per case in Switzerland provided an opportunity to study regional differences in inpatient interventions and possible influencing factors using high-quality data.

The aim of the study was to identify temporal and regional differences in the performance of inpatient elective interventions in Switzerland based on flat-rate data and to explain possible differences.

The data from 2013 to 2018 showed that in some hospital regions, cement was injected 17 times more frequently for vertebral fractures, and pacemakers and defibrillators were implanted seven times more frequently than in other regions. In some regions, prostate surgery, the implantation of hip and knee joint prostheses or the removal of the uterus were performed two to three times more frequently. An increase over time was observed, for example, for the injection of cement for vertebral fractures and a decrease for uterus removal. In the case of uterus removal, there were also greater differences in the surgical technique chosen. The regional differences could only partly be explained by factors such as age, gender, socioeconomic factors, or concomitant diseases. The greater part of the differences presumably is explained by personal preferences of the attending physicians.

Significance of the results for research and practice

The present study shows significant regional differences in the frequency of performing elective medical interventions. For the most part, these cannot be explained by patient characteristics or socioeconomic factors. Moreover, it seems unlikely that patients' medical needs or preferences differ significantly between regions. In many cases the personal preferences of the attending physicians are likely to be the decisive factor in whether a particular elective intervention is performed or not. This could be remedied by medical guidelines and patient information containing decision-making aids when an intervention is appropriate. The methodology used in the study provides a suitable basis for tracking regional trends in health care in the context of a future Swiss Health Atlas.

Variations in preference-sensitive care and controversial medical procedures in Switzerland