The DIOGENE hospital information system (HIS) is the primary electronic medical record (EHR) used by the University Hospital in Geneva Switzerland. Since it's development and implementation, the system has been expanded to include a centralized and integrated patient clinical database which stores structured patient data. The main objective of DIOGENE HIS was to provide a standardized framework for the building of future clinical databases and for the integration of existing heterogeneous ones. It is an evolutionary view of longitudinal clinical activities spanning the various departments/specialties.
For the purpose of enabling communication and exchange of data within the DIOGENE HIS, a new controlled vocabulary for representing clinical data has been created. The construction of this vocabulary is based on the international ICD classification (ICD-9), already being used in DIOGENE for encoding patient diagnosis and procedures. A new extension of the ICD is proposed for medical information that goes beyond diagnosis and procedures encoding. The building of a common clinical findings dictionary, recording the definition of clinical entities, is based on this newly developed clinical vocabulary. This process is incremental, manual and substantial.
Four axes of knowledge
DIOGENE HIS integrates four axes of knowledge:
- Medical - Economical context, to provide clinicians and administration a better understanding of resource usage which may help prevent duplication of services.
- Complete set of Patient reports and documents, to enable clinicians access of patient information 24/7. It will provide encoded summaries, lab data & images, and detailed clinical finding (patient-dependent knowledge)
- Maintenance of knowledge base, such as Medline, to provide clinicians and patients with evidence based guidelines (patient-independent knowledge)
- The integration of these patient-dependent and independent knowledge in a case-based reasoning format, aims to provide on the the clinical staff and the physician desktop all relevant information for helping him to take the most appropriate adequate decision.
Diogene was developed in the 1970's  by the Professor Jean-Raoul Scherrer at the University Hospital in Geneva, Switzerland.  The need for this hospital information system arose as medical expenses had to be directly compared to the quality of healthcare providedand outcome analysis became an integral part of hospital's as well as physician's performance measurement.
The system had both a centralized patient database, and centralized group of operators who trained and supported users. The centralized patient database included mechanisms for data protection and recovery of a transaction-oriented system. It also included a separate network of remote printers that provided service throughout the entire institution; and a three-component structure that enhanced communication between administrative and medical applications . It retained its architectural unity until Diogene 2 was launched.
In 1993, Unimage, a radiology information system was created and implemented at the Cantonal University Hospital of Geneva as a part of the migration towards the Diogene 2 hospital information system. It was designed to fit the needs of the radiology department, and to operate in different services, (i.e. diagnostic radiology, nuclear medicine and therapy radiology) offering a simple two-way data communication with the PACS world; created for a distributed environment, as well as a graphical (X/Motif) user interface. 
In June 1995, the need for modification and extension over the years led to the creation of a full-scale distributed/open hospital information system “Diogene 2” . "Diogene 2" integrated technology by incorporating knowledge bases such as Medline; providing relevant information for helping the physician to make adequate decision on medico-economical issues to understand resources consumption .
In 1999, an effort was made to integrate the many clinical databases that have developed over the years in different hospital departments with "Diogene 2". The challenge was in the different systems developed by different teams with different references and vocabulary  . Therefore, a newly developed clinical vocabulary was created based on the international ICD classification which facilitated the communication and exchange of data .
Doclin is a clinical information system that is integrated with DIOGENE. DOCLIN was created for the communication and the exchange of data between different medical departments at the University of Geneva that had independently created and operated databases. The 4-year project began in 1997.  The DOCLIN architecture is composed of three main parts:
- the Clinical Finding Dictionary Manager (CFDM)
- the Medical Questionnaire Designer (MQD)
- the Medical Questionnaire Editor (MQE)
These parts are linked to one or more databases. 
The purpose of the 4-year project was to expand DIOGENE with clinical data and medical protocals to form the DIOGENE HIS. The new HIS was an open network of information systems managing many types of data. The data types included admission and discharge data, laboratory data, coding and patient medical records. 
Diogene now supports many applications including lab, radiology, and pharmacy . It went from centralized to an open distributed architecture; therefore, reaching other public hospitals and general practitioners in Geneva.
Methicillin-resistant Staphylococcus aureus (MRSA) is a growing international health risk. Admission of an infected or colonized patient into a hospital poses a significant risk and requires appropriate infection control measures (ICM) to prevent or reduce transmission. At the University Hospital of Geneva, investigators applied an expert system within their DIOGENE hospital information system to deliver daily alerts to the Infection Control Program office. Two different alert mechanisms were implemented. The first is a "readmission alert" that is generated for any patient admitted to the hospital with a documented previous infection or colonization from a prior hospital visit. The second is a laboratory alert generated each day at 1:15 pm consisting of two reports:the positive lab alert, which consist of a listing of patient information from positive cultures for MRSA within the preceding 24 hours and a surveillance cultures report for all MRSA cultures with no growth within the preceding 24 hours
During the first 12 months the system was active, the lab alert identified an average of 4.6 isolates each day. This translates into a total of 248 patients representing 314 admissions. In addition, 438 readmission alerts were generated, 33% of which (114) were found to be positive for MRSA. 
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- Breant C. A Hospital-Wide Clinical Findings Dictionary Based on an Extension of the International Classification of Diseases (ICD) http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=2232696&blobtype=pdf
- Bréant C, Borst F, Campi D, Griesser V, Le HS. Expanding DIOGENE with a clinical information system based on a new hospital-wide clinical finding dictionary.
- Breant C. Expanding DIOGENE with a clinical information system based on a new hospital-wide clinical findings dictionary http://www.ncbi.nlm.nih.gov/pubmed/10978919