## 2 Transformation of the Healthcare System in Poland: Current State  
The transformation of the Polish healthcare system can be anchored in the fall of communism in 1989. For the next decade, an amplified effort was put toward moving from the Siemaszko Model to a decentralized healthcare system [9]. The Siemaszko Model [10] was a holdover system from the former system and was an example of the centralized model in which the government financed it fully and there was no private healthcare sector. In 1999, the Act of 6 February 1997 on Universal Health Insurance came into effect, effectively institutionalizing an insurance-based model [11]. The next milestone was in 2003 when the Act of 23 January 2003 on Universal Health Insurance in the National Health Fund came into effect, introducing unified rules for financing healthcare services and ensuring equal access to health services for insured individuals [12]. The year 2011 marks a step toward digitizing medical records in the form of [13]. Since 2021, Poland has operated the P1 System, the \"Electronic Platform for Collection, Analysis, and Sharing of Digital Resources about Medical Events\", consolidating comprehensive information on medical events [14]. In Poland, adopting the International Statistical Classification of Diseases and Related Health Problems 11 th revision (ICD-11) is an ongoing process [15]. On 24 November 2023, pre-release version ICD-11 in the Polish language was released, which concluded phase one of the implementation of ICD-11. The implementation process for ICD-11 in Poland is anticipated to continue until at least 2025, possibly extending until 2026 [16]. The deadline for the whole project is 30 November 2027, meaning that ICD-11 is fully incorporated within the Polish healthcare system and adapted to international standards [17]. The P1 system aligns with the concept of interoperability as defined in documents [18; 19]. As outlined in [20], interoperability is attainable through the following:  
* Unification involves utilizing the same set of norms, standards, and procedures by all parties. * Interchangeability, signifying the ability to replace a product, service, or process without interrupting information exchange between parties, simultaneously meeting all relevant system requirements. * Compatibility, indicating the utility of products, processes, and services that meet specified requirements without adverse side effects. The P1 system (Figure 1) adheres to standards such as ICD-10 [21], Systematized Nomenclature of Medicine--Clinical Terms (SNOMED CT) [22], and Logical Observation Identifiers Names and Codes (LOINC) [23], establishing itself as an interoperable system. By embracing globally recognized standards, the P1 system facilitates the accurate coding of patient data, seamless sharing, and integration into Electronic Health Records (EHRs). Furthermore, the P1 system supports interoperability based on IHE recommendations by implementing recommended profiles [24]. In alignment with Health Level 7 (HL7) recommendations and the Digital Imaging and Communication in Medicine (DICOM) or ISO 12052 [25], the P1 system ensures interoperability and remains current with global healthcare practice. On top of that, the Polish implementation incorporates an HL7 Clinical Document Architecture (HL7 CDA), which is \"a document markup standard that specifies the structure and semantics of clinical documents\" for exchange between healthcare providers and patients. It defines a clinical document structure as having the following six characteristics: (1) Persistence, (2) Stewardship, (3) Potential for authentication, (4) Context, (5) Wholeness, and (6) Human readability [26]. It provides 284 templates and a dictionary of medical terms used within documentation [27]. In [28], the author briefly describes the roles and development of six systems in healthcare.