The term NPI has been used by scientists working in the health field since 1975. However, it is not the only term; other similar terms are used synonymously, especially in PubMed. There are ten English terms to describe non-pharmacological processes and twenty-eight to describe methods of operation. An exhaustive inventory of NPI on a scientific article search engine is currently impossible due to the variety of terms researchers use, each with distinct meanings: rehabilitation intervention, psychosocial intervention, mental intervention, cognitive intervention, psychological intervention, behavioral intervention, psychosomatic intervention, nutrition intervention, dietary intervention, food intervention, physical intervention, body intervention, exercise intervention, manual intervention, salutogenic intervention, natural intervention, self-help intervention, nursing intervention, therapy intervention, care intervention, disease management intervention, multimodal intervention...

A search on PubMed from August 15, 2024, indicates 55,689 articles citing the term "non-pharmacological" or its equivalent up to 2023. While these figures do not challenge the trend, they are likely underestimated due to the database's focus on health products rather than services, biological treatments over psychosocial ones, studies on North American populations, and journals published by North American organizations. This aligns with an official U.S. government site managed by the National Center for Biotechnology Information and hosted by the National Library of Medicine, part of the National Institutes of Health (NIH).

A search on PubMed from August 15, 2024, also reveals 11,642 articles citing the term "non-pharmacological intervention" or its equivalent up to 2023. Both curves demonstrate an increase since 2000, with a notable acceleration since 2010.

The French National Authority for Health has been encouraging the use of the term NPI in health since 2011.

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.

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 choice and implementation of an NPI at a given moment in a person's prevention and care journey do not depend on the NPI Registry, nor on the mission of the NPIS. These decisions are influenced by individual health situations, preferences, the availability of professionals, the qualifications of practitioners, accessibility in a given area, and socio-cultural contexts. The art of combining NPI with each other and with other health solutions at the right time lies with professionals, expert systems, interdisciplinary organizations, and the healthcare system in place in a specific country. The NPI Registry highlights essential practices that have proven effective and continue to evolve through research and feedback analysis. The NPIS has no authority to impose a choice of NPI. Each professional is free to follow them, to pursue others, or to create new ones. The same applies to each healthcare organization.