Effectiveness of auriculotherapy on stress reduction in health workers: a controlled randomized clinical trial

Abstract Objective: to assess the effectiveness of auriculotherapy in reducing occupational stress among Family Health Strategy workers during the COVID-19 pandemic. Method: a controlled randomized clinical trial divided into two groups, namely: auriculotherapy for stress group and placebo group. The Shapiro-Wilk test was used to assess data normality. The ANOVA test for repeated measures and the Tukey post-hoc test were applied to the group with normal samples. In turn, the Friedman and Durbin-Conover tests were employed in the group with non-normal distribution. Cohen’s d index was calculated for the therapy effect size. A 95% significance level and p<0.05 were considered. Results: the auriculotherapy group presented 16.3% and 23.7% reductions in occupational stress after the third and sixth auriculotherapy sessions, with Cohen’s d indices of 1.12 (large effect) and 1.82 (very large effect), respectively. Conclusion: auriculotherapy proved to be effective in reducing occupational stress among Family Health Strategy workers during the COVID-19 pandemic. It is suggested that new studies are developed both during and after the pandemic in order to improve health workers’ Quality of Life. ReBEC registration: RBR - 38hjyt3.


Introduction
Occupational stress is defined as chronic wear out resulting from environmental and organizational factors at work that can lead to physical, mental and behavioral changes such as high blood pressure, heart attack, anxiety, irritability, headache, physical exhaustion, gastric ulcers and insomnia, among other pathologies and symptoms (1)(2) .
Health workers are exposed to a series of challenges in the work environment that are favorable to the development of occupational stress, such as interprofessional relationships, dealing with suffering, pain and even death of patients, lack of supplies, materials and equipment, high demand and working hours, situations of violence against workers, low wages and precarious working conditions (3)(4) .
The COVID-19 pandemic caused by the new SARS-CoV-2 coronavirus not only intensified workload and demand, making them exhausting, but also brought about new challenges, such as fear of infection by the virus, lack of knowledge about the new disease, distance from the family and stigma towards health professionals, contributing to increased psychosocial and mental distress (5)(6)(7)(8) .
In this sense, it is essential that actions and strategies be targeted at health workers in order to alleviate occupational stress and provide better Quality of Life. Integrative and Complementary Health Practices (ICHPs) can be an excellent alternative for the worker's lines of care, as they are low-cost, have no side effects, and contribute to the reduction of medicalization and of the frequency of mental disorders (9) . Care Network (10) .
Among these practices, auriculotherapy is a therapy from the Traditional Chinese Medicine that is recognized by the World Health Organization (WHO). It consists in stimulating ear points using needles, metallic spheres or seeds, to produce nerve impulses that reach the brain, stimulating the central and vegetative nervous systems, with release of endorphins, neurotransmitters and neuromediators that regulate body balance and treatment of diseases and behavioral and psychosocial disorders, such as stress (11)(12) . In this direction, a number of studies already point to the effectiveness of auriculotherapy in reducing occupational stress among health workers (13)(14) .
Given the above, the current study intends to assess the effectiveness of auriculotherapy in reducing occupational stress among Family Health Strategy workers during the COVID-19 pandemic.

Study design
A single-blind controlled randomized clinical trial based on the Consolidated Standards of Reporting Trials (CONSORT) statement (15) .
Controlled randomized clinical trials are considered the reference standard regarding research methods in epidemiology due to better determination of an intervention efficacy. They are characterized for being experimental, having a prospective architecture, including a control group and sample randomization (16) . This randomization has the purpose of assembling groups with similar characteristics where factors that may confuse interpretation of the results have their effects neutralized from the equal distribution of these characteristics among the groups (17) .  The participants answered the questions by choosing one out of five options: 1-I totally disagree; 2-I disagree; 3-I partially agree; 4-I agree; and 5-I totally agree. The highest score is assigned to the highest stress levels (18) .

Ethical aspects
The research was approved by the Ethics and

Results
There was a total of 145 Family Health Strategy  Table 2.  In turn, in the placebo group the stress reduction between the first and second stages was 8.26%, with a Cohen's d index of 0.44 (small effect) (19) . Between the first and third stages, the reduction corresponded to 11.7% and Cohen's d was 0.62 (average effect) (19) . In turn, between the first and fourth stages, the reduction was 13.4% and Cohen's d was 0.75, also considered as average effect (19) . As there was normality of the groups paired in the placebo group, the ANOVA analysis for repeated measures was used, finding a statistically significant relationship (p=0.01), but only between the WRSS1/WRSS4 paired groups (p=0.039). The intervention the remote modality, 06 were on medical leave, and 29 refused to participate in the research. Thus, 11 workers were excluded from the research according to the eligibility criteria from the first stage, totaling 105 participants at the end.
The overall stress mean in the sample was 2.81, representing the cutoff point for categorizing it into low and high occupational stress level. A total of 56 participants (53.33%) presented low stress level and 49 (46.67%) were classified as with high stress level.
The absolute and relative frequencies of the sociodemographic and work-related variables in each randomized group are described in Table 1. No medical professionals took part in the intervention phase. Nurses, nursing technicians, dentists and oral health assistants were categorized as health professionals. size effect through Cohen's d index in both groups is represented in Table 3.

Discussion
The COVID-19 pandemic is known to have caused an increase in mental and psychosocial disorders among health workers worldwide (5)(6)(7)(8) . and occupational stress during the COVID-19 pandemic.
The following stand out among them: a study conducted with Nepalese individuals pointed out that 12% of the participants presented occupational stress, 30% anxiety and 22.5% depression (20) . Among Indian health workers, the values for acute occupational stress, depression and anxiety were 9.5%, 17% and 19.5%, respectively (21) .
Occupational stress in health workers from a municipality in the state of Maranhão, Brazil, through the Perceived Stress Scale, presented 20.5% frequency in the very high level and 23% in the high level (22) . Among hospital health workers in Egypt, perceived stress at moderate and severe levels accounted for 98.5% of the sample, while moderate anxiety had a frequency of 32% and severe anxiety, of 18.5% (23) . In turn, in the pandemic front-line health teams from Greece, the prevalence of moderate/severe symptoms of depression, anxiety and post-traumatic stress was 30%, 25% and 33%, respectively (24) . showed good acceptance by the workers, improvements in individual and collective well-being, and pain, anxiety and stress relief, improving performance in work activities (25) .
ICHPs contribute to a reduction in mental and emotional symptoms and improve sleep quality and wellbeing. Therefore, they must be made available to health professionals, as well as they should be empowered both for self-care and support to others (26) .
Auriculotherapy is on the list of ICHPs and has been an important tool used for reducing psychosocial and mental distress, as well as behavioral, emotional and physiological changes. In addition to that, it is a viable practice because it is cost-effective, easy to apply and learn, fast, safe and has presented good acceptance (11,27) .
The auricular pavilion is made up of specific points whose stimulation is related to effects regarding relief of muscular and skeletal pain, treatment of mental, emotional and behavioral disorders and control of cardiovascular and gastric diseases, among others (11)(12) .
The Shenmen point, for example, is considered a calming, analgesic, anti-inflammatory and soothing point while the Brainstem point has sedative properties and helps calm the mind. They are both indicated for stress control. The External Ear and Wrist points are indicated for problems in their respective regions; therefore, unrelated to stress (13)(14) .  after the end of the therapy, respectively (14) .
Our findings presented positive results after fewer auriculotherapy sessions (6) Despite a lower reduction in occupational stress when compared to the auriculotherapy group, the effect in the placebo group can be due to the periodic and scheduled meetings with the participants focused on mental health care, providing a sense of support, care and welcoming through auriculotherapy, especially during the pandemic period, as cited in the literature (14) .