About 8,500,000 Brazilian adults over 18 years old reported using one or more CAM in 2019, equivalent to 5.2% of the country's population, an increase of 0.7% in the prevalence of CAM use compared to the PNS-2013 research. Medicinal plants were the most frequently used CAMs in Brazil, with substantial regional differences: while in the Southeast, a more industrialized and urbanized Brazilian region, the use of acupuncture was more frequent, in the Northeast and North regions, that contains most of the Amazon Forest, the use of medicinal plants was more frequently reported by the population. This heterogeneity was maintained when comparing these findings with those of the PNS-2013.
Brazil has five regions, with significant sociodemographic and health differences between them. The South and Southeast regions are the most densely populated and economically developed, with better health indicators, better access to health services15, and longer life expectancy16 than the North, Northeast, and Midwest regions. The North region concentrates more than 80% of the indigenous population17, likely influencing the higher prevalence of medicinal plants. Paradoxically, the North region has the lowest offer of CAM in primary health care18. Indigenous practices and their cosmological perspectives are not incorporated into the National Policy on Integrative and Complementary Health Practices of the Unified Health System and other famous practices such as prayers, healers, and midwives19. In Brazil, the discussion about the insertion of these traditional practices into policies is still incipient and has not received adequate research support, so we do not know what percentage of the population seeks this type of care19. We can assume that if these practices were incorporated into the PNS questionnaire, the prevalence of CAM would be even higher in this region.
The present study also observed that female individuals with complete higher education, per capita family income higher than two minimum wages (more than $502.83), and aged 40 years or more were more likely to use one or more CAM. This profile of CAM use is similar to that observed in another studies 20–22 . According to the PNS 2019, the demand for health services, in general, was higher among older women with a high level of education 23 . CAMs are also used as a therapeutic alternative and provide, in addition to physical relief, an improvement in quality of life, well-being, and anxiety control 24,25 . Studies show that many women would like to avoid pharmacological or invasive pain management methods, especially during childbirth, encouraging them to use non-biomedical practices such as acupuncture 26 . Some studies have also shown that women use integrative practices at different stages of life, such as during pregnancy, postpartum to climacteric, and menopause 27,28 .
The present study observed that individuals with better access to health care are more likely to use CAM, and in the adjusted analysis, it was possible to observe that these individuals were more likely to use acupuncture, homeopathy, and yoga, respectively. These findings suggest possible inequalities in access to health services, as these practices require specialized professionals who might not be available in the Brazilian Unified Health System. In the PNS -2013, it was observed that acupuncture and homeopathy are among the most used CAMs by those who had a private health plan10. In PNS- 2019, it was not possible to analyze the use of CAM through a private, out-of-pocket, or health plan.
The federal government adopted The Family Health Strategy to expand Primary Health Care in Brazil, covering 65% of the country's population29. Brazil's Family Health Strategy has been offered most CAM, despite the disparity between the Ministry of Health and independent surveys29,30,18. Studies observed that some Family Health Strategy professionals offer CAM in the Unified Health System by their initiative and expenses.
There is still a mismatch between the supply and use of CAM, especially within the Unified Health System. The Ministry of Health of Brazil30 reports an increase in the supply of CAM in the Unified Health System across the country. However, the use of CAM through the Unified Health System is still relatively low18,6,10. Studies have shown that the offer in Brazil is dependent on health professionals; that is, there is no specific financing, and the offer depends most on the willingness of the health professional to offer CAM services18. Thus, practices that require specific inputs (such as acupuncture) and higher specialization, such as Acupuncture and Homeopathy (a specialty restricted to medical activity in Brazil), continue to be offered less, even after 15 years of National Policy on Integrative and Complementary Practices implementation18.
Regarding self-rated health, the present survey observed that individuals who reported having regular, poor, or very poor health are more likely to use CAM compared to those who reported having better health status. In the evaluation by type of CAM, it was also possible to observe that those who declared a worse health situation are more likely to use acupuncture or medicinal plants. Similar results associating worse health status and greater use of CAM were observed in other studies31,21,12. Having a private health insurance plan also increased the chances of using CAM, and similar findings were found in other surveys32,33,20.
Meditation, yoga, tai chi chuan (or lian gong or qi gong), integrative community therapy, and auriculotherapy are CAM that was not included in the PNS- 2013 and were included in 2019 after insertion in the National Policy on Integrative and Complementary Practices. The present study observed a low prevalence of tai chi chuan (or lian gong or qi gong), and integrative community therapy. Meditation and yoga also had a low prevalence use among Brazilian adults. A population survey conducted in the United States found a prevalence of 8.9% in yoga among adults, but in the United Kingdom, this prevalence was lower at 1.1%34,35. Regarding meditation, a survey conducted in the United States found a prevalence of 18.6% in adults36.
The yoga and meditation profile practice stood out in the PNS-2019 among female individuals with private health insurance, access to health services, and reported better self-rated health. Individuals with complete higher education were more than ten times more likely to use these two CAM types than others. We can observe that these are types of CAM used by individuals with higher incomes. Similar results for yoga were observed in studies conducted in the United States, the United Kingdom, and Germany37,35,34.
In Brazil, studies about the prevalence of the practice of yoga and meditation are still scarce; however, these practices are understood as a form of health promotion, disease prevention, and even as a therapeutic action, thus being adopted by the Unified Health System within the scope of primary care in health38. Yoga, tai chi, meditation, among others, have been offered in the Brazilian health system as a set called bodily practices, which can confuse the population in general, as there is not always a distinction about each of them. However, this is the fastest-growing supply in the country, with a more than 200% increase in the number of services and the one with the highest number of services offered per population 2.20/100000 inhabitant6. Studies have shown that yoga and meditation have also been presented as spiritual practices, used mainly for people affected by cancer and other chronic conditions to promote health and quality of life39,40.
An extensive systematic review reported a variability by which CAMs are defined and classified in studies9, making it difficult to compare the use of these practices across populations. The type of sampling and the target population is a factor that can influence research results. Several studies focus on specific populations or subjects, which can generate an information bias. An example is the high prevalence of CAM use in studies with individuals with specific illnesses (especially chronic or terminal illnesses), while we find lower prevalence in population-based studies such as the Brazilian PNS41–43.
Information bias, resulting from the way information about CAMs was collected, may have influenced the results of this study as respondents may not remember any use of CAM or even not consider such practice or therapy to be CAM44,45. In the PNS-2019, a “filter” question was asked in which the respondent had the option of answering “yes” or “no” for the use of eight CAMs previously listed, and if the answer was “yes” to the use of these CAMs, the subsequent questions about each of the eight CAMs were carried out separately. This procedure may have underestimated the prevalence of CAM use in Brazil, which could have been avoided if all eight CAMs selected by the research coordination were read in sequence, allowing the respondent to respond positively or negatively to each type of CAM separately. However, as Unified Health System offers 29 types of CAM, we believe that including all of them in the survey would possibly reduce the information bias, which could reflect a higher prevalence of the use of these therapies.
Another limitation of the study was the non-assessment of the out-of-pocket amount for the use of CAM. Unlike the PNS-2013 analyses, it was impossible to know whether the individual used CAM by Unified Health System, health insurance, or private individuals. The PNS -2019 questionnaire did not cover this information. On the other hand, the strength of the research was its population representation, having reached adults from all socioeconomic strata and allowing the generalization of the results.