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.

The term non-pharmacological intervention (NPI) was not chosen by the scientific society NPIS but has become necessary. It has been used by scientists since 1975. Various authorities and agencies have adopted it, including the World Health Organization since 2003, the French National Authority for Health since 2011, the National Solidarity Fund for Autonomy since 2014, the Ministry of Health since 2018, the High Council for Public Health since 2019, the European Centre for Disease Prevention and Control since 2020, the General Inspectorate of Social Affairs since 2022, the Economic, Social and Environmental Council since 2023, and Health Insurance since 2024. Many national and supranational scientific societies use the term NPI in their recommendations. These health solutions are often "squeezed" between health products and public health measures, despite efforts by professionals to raise awareness and recognition of them. They represent an underestimated area of intangible services situated between goods (e.g., medications, medical devices) and general public health recommendations (e.g., dietary rules, hygiene measures, environmental actions).

They can be lost in compilations of health solutions that mix health promotion actions with targeted programs or confuse methods for identifying a health problem with methods for resolving it. The challenge is to improve the traceability of practices for continuous enhancement of their quality, safety, implementation, and training. These practices can be easily shared from one country to another. The term NPI does not imply "anti-medication" or "alternative medicine" (parallel medicine). Instead, it draws from the rigor of the globally standardized drug validation process to establish good scientific and clinical practices. Over time, we believe that the abbreviation NPI will come to be more widely recognized than its full title, similar to WHO, IBM, SEAT, and many others.

Registers of non-pharmacological practices with imprecise criteria and boundaries.
Catalogs compile various health practices among which NPI may be submerged. Some target the general population, while others are more specific. The selection criteria are heterogeneous, and objectives and practical modalities vary widely. Three examples include two from the United States (EBCCP and Mindtools) and one from France (Capitalisation Santé).

A scientific validation model for medications has existed since the 1960s, with specific regulations recognized worldwide (e.g., FDA, EMA, ANSM). A similar procedure has recently been implemented for medical devices in Europe. However, until now, no consensual model existed for nutritional, bodily, and psychosocial health services due to confusions between approach, protocol, and technique/ingredient. A participatory, pragmatic, and multidisciplinary consensus work followed international scientific health recommendations to address this for NPI (Ninot et al., 2023).

This work took into account the specificities of NPI, health risks, the balance between internal and external validity, the justification of explanatory mechanisms, ethical considerations in health, and respect for contexts of use. The NPIS Model accelerates research through the harmonization of methodological and ethical expectations in NPI. It also enhances the identification, referencing, transferability, and implementation of NPI for the benefit of user health and safety, improving the quality of training.

Ultimately, the NPIS Model distinguishes between individualized, science-based services aimed at addressing known health issues in Western medicine and occupational practices (lifestyle, art of living, work, sociocultural activity, personal development, pursuit of happiness, spiritual practice, etc.). In this sense, the model does not impede individuals' freedom to choose a particular lifestyle. It aims to address a specific health issue for an individual or a group of people within a limited timeframe and a framework regulated by the health sector. The NPIS Model encourages innovations across all other health sectors, particularly in health organizations and early identification actions for health problems.