The Swiss solution for anonymously chaining patient files

Area of Science:

• Public Health
• Health Informatics
• Epidemiology

Background:

• Linking successive hospitalizations for epidemiological surveys requires robust patient anonymity preservation.
• Switzerland's Federal Statistical Office manages medical hospital statistics.

Purpose of the Study:

• To describe the anonymous record linkage procedure adopted by Switzerland for medical hospital statistics.
• To ensure patient anonymity while enabling the linkage of hospital admission data for epidemiological purposes.

Main Methods:

• Development of concepts, algorithms, and organizational frameworks by the Federal Statistical Office.
• Implementation of an anonymous record linkage procedure involving irreversible identity transformation.
• Adoption of algorithms similar to those developed at Dijon University Hospital.

Main Results:

• Successful implementation of an anonymous record linkage procedure in Switzerland.
• Irreversible transformation of patient identity data is ensured.
• Anonymous health files can be effectively linked for statistical and epidemiological surveys.

Conclusions:

• The implemented anonymous record linkage procedure effectively links successive hospitalizations while guaranteeing patient anonymity.
• Switzerland's approach provides a model for secure data linkage in epidemiological research.
• The developed algorithms are comparable to established methods used in other leading institutions.