Related Experiment Video
Updated: Jul 13, 2026

Systematic Assessment of Well-Being in Mice for Procedures Using General Anesthesia
Published on: March 20, 2018
[Fair hospital comparisons -- does the method contracted in Germany enable unbiased results?]
1Universität Regensburg, Klinik und Poliklinik für Psychiatrie, Zurich, Switzerland. ulrich.frick@bli.unizh.ch
Aim:
To evaluate the method for comparison of average length of stay in hospitals as defined in a contract between German health insurance companies and the "Deutsche Krankenhausgesellschaft" (German Hospital Association).
Method:
Simulation study executing the algorithm agreed upon in different scenarios, which varied the number of hospitals to be compared, the dispersion of diagnostic specialization over hospitals, and the distribution of hospitals' sizes. Scenarios were constructed to realistically reflect the situation in German inpatient treatment of mentally ill patients.
Results:
By fixing casemix adjustments only on diagnoses of patients and by doing so aggregated on the level of hospitals, the method for comparison yielded artificial differences between hospitals even in a situation where each patient is treated with exactly the same amount of resource allocation (given the individual needs defined for all scenarios). Results of artificial differences were heavily biased against or in favour of the reference hospitals according to the specific condition of the scenario parameters.
Conclusion:
The contracted method is not capable of achieving fair hospital comparisons, at least not for psychiatric hospitals.
Related Concept Videos
Blind Procedures
Bonferroni Test
The means of different samples are first paired in all possible combinations.
The null hypothesis of the...
Bias
In statistics, a sampling bias is created when a sample is collected from a population, and some members of the population are not as likely to be chosen as others (remember, each member...
Behrens–Fisher Test
This test is...
Friedman Two-way Analysis of Variance by Ranks
Comparing the Survival Analysis of Two or More Groups

