An evidence-based data point is a theoretical or practical knowledge acquired through rigorous and integrated scientific methods and reasoning. The NPIS Model follows this logic in the health field (see Figure 3). It provides specific methodological and ethical recommendations for NPI for studies focusing on their mechanisms and explanatory processes (mechanistic study), their content (prototypical study), their evolution over time (observational study), their benefits and risks (interventional study), and their application and personalization modalities (implementation study).

As of April 2019, there were 46 evaluation models for NPI in the scientific literature (Carbonnel and Ninot, 2019). These models were constructed by researchers for researchers, often from a monodisciplinary perspective and rarely from a patient-centered approach. This led to significant heterogeneity in study protocols and the way NPI were conceived (approach, method, technique, or materials). The results were scattered, debatable, poorly transferable, and rarely reproducible. Consequently, these practices were not widely recognized outside the study context (dependent on the establishment and/or practitioner). This situation raised doubts about their effectiveness (e.g., efficacy, safety, relevance, utility, cost-effectiveness), their content (e.g., heterogeneity in doses, procedures, ingredients, techniques, contexts, target populations), their approval (e.g., ethics committees), their dissemination (e.g., conflicting reviewer opinions), their teaching (e.g., protocols, best practices), and their recognition (e.g., authorization, integration into official classifications, reimbursement). This lack of a consensual evaluation model for NPI suggested that each professional had to reinvent their program for every new patient, given the wide or contradictory recommendations from authorities, agencies, and scientific societies. It also implied that only the patient-provider relationship mattered in the health effects induced (Ninot, 2020). Moreover, it left the door open for pseudoscientific practices and, more broadly, parallel medicine, along with all the obscurantist, health-related, sectarian, political, and judicial issues that are known in France (Miviludes, 2022; CNOI, 2023; CNOM, 2023) and around the world (Ernst and Smith, 2018). This idea was also gaining traction in the United States in the field of oncology, aiming to juxtapose two medical offerings: one based on experimental science, primarily focused on surgery, medication, radiotherapy, and medical devices, and the other described as "complementary, integrative, or traditional," based on individual experience, opinions, and traditions (Mao et al., 2022). This second offering claimed exclusivity in the domains of prevention and care, emphasizing care for the person versus cure for the disease. Thus, the NPIS Model was co-constructed with the idea that experimental science could demonstrate the existence of effective, safe, and reproducible prevention and care protocols. This work was supported by seed funding for participatory research from INSERM and involved over 1,000 participants under the guidance of a committee of 22 multidisciplinary experts, including two user representatives. This transdisciplinary innovation is currently supported by 30 French scientific societies, the National Center for Palliative Care and End of Life, INCa, and the French Platform for Clinical Research Networks.

Immaterial practices of prevention and care have existed since ancient times. However, the diversification of practices, the multiplication of professions at the intersection of prevention, care, and social assistance, and the globalization of information systems have leveled these services and obscured them at a time when medicine has made significant advances in the early detection and diagnosis of health issues. The interdisciplinary and multisectoral approach of the NPIS generates a value chain, from the design of practices to their implementation, regulation, and financing.

Innovative economic model initiatives are emerging worldwide, including fee-for-service, bundled payments, social economy provisions, offers promoting sustainable development, e-health economy, human innovation bundles, and long-term economy (World Economic Forum, 2024). The NPIS Prospective Pole, led by Michel Noguès, documents these initiatives in books (Noguès, 2022; Noguès, 2024). The NPIS Forums invite all innovators to share their experiences.

In France, the term "professional" is broader than the term "practitioner," which is limited to the 24 healthcare professionals defined in the Public Health Code (CSP). For example, a clinical psychologist and a teacher in adapted physical activity (APA) are professionals who work for the health of individuals by offering NPI for preventive or therapeutic purposes, but they are not considered "health professionals" in the strict sense of the CSP. Some professions fall under the Social Action and Families Code (e.g., specialized educator) or the Sports Code. In Europe and worldwide, the issue becomes more complex because health-related professions do not share the same designations. For instance, "masseur-kinésithérapeute" in France is referred to as "physiotherapist" in most other countries. NPI can serve as common denominators across countries, as they will have a unique code and specification sheet.

The connection between mechanistic, interventional, and implementation studies forms the backbone of the epistemological positioning of the NPIS Model regarding the evaluation of NPI. This does not mean that an interventional study, for example, cannot explore biological mechanisms or psychosocial processes. Instead, this backbone provides coherence to the studies and structures the validation process of NPI for integration into a standardized practice framework.

Each NPI file in the NPI Registry has been submitted by a practitioner or researcher through the dedicated platform hosted by the NPIS. Each file undergoes review by an independent and integrated scientific committee. This committee invites relevant scientific societies and health authorities to validate the NPI files and/or to oversee the decisions made. Each validated file is then reviewed by a committee of users and professionals. Once labeled NPIS©, the file is translated into at least English and French and integrated into the NPI Registry.

The file contains standardized content supported by scientific studies that align with the NPIS definition of NPI, the expected specifications (Table 2), and the consensual evaluation framework for NPI, known as the NPIS Model. It includes a manual for professionals, an information notice for users, a section on funding options, and an area for anonymous user feedback. This ensures the file remains dynamic and part of a virtuous cycle of continuous improvement for the NPI.

A minimum of one prototypical study, one mechanistic study, two interventional studies, and one implementation study published in a peer-reviewed journal is required for an NPI proposal to be accepted by the expert committee tasked with validating the NPI file and awarding the NPIS© label. Specifically, experts must have evidence to anonymously vote on each criterion of the NPI file proposed to the NPIS by a submitter:

• Described (≥ 1 prototypical study)
• Explainable (≥ 1 mechanistic study)
• Effective (≥ 2 interventional studies)
• Safe (≥ 2 interventional studies)
• Implementable (≥ 1 implementation study in the country)

A professional must understand all the specifics of the NPI, the criteria justifying its use, how to implement its protocol, whom to contact, useful tips, required materials, and any prerequisite training needed.