SciELO - Scientific Electronic Library Online

 
vol.26 número1Queixas musculoesqueléticas no ombro: características dos usuários e dos atendimentos na atenção primáriaProfissionais da saúde que atuam em ambiente hospitalar têm alta prevalência de fadiga e dorsalgia: estudo transversal índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

Compartilhar


Fisioterapia e Pesquisa

versão impressa ISSN 1809-2950versão On-line ISSN 2316-9117

Fisioter. Pesqui. vol.26 no.1 São Paulo jan./mar. 2019

https://doi.org/10.1590/1809-2950/18024126012019 

ORIGINAL RESEARCH

Chronic spinal problem/back pain in quilombola populations of Bahia, Northeast of Brazil

Emille Prates Teixeira1 
http://orcid.org/0000-0001-7629-7216

Ricardo Franklin de Freitas Mussi2 
http://orcid.org/0000-0003-1515-9121

Edio Luiz Petroski3 
http://orcid.org/0000-0001-8480-0846

Hector Luiz Rodrigues Munaro4 
http://orcid.org/0000-0002-6421-1718

Ana Claudia Morais Godoy Figueiredo5 
http://orcid.org/0000-0003-2842-9848

1Group of Studies, Research and Extension in Education, Culture and Health, Aracatu (BA), Brazil. Email: emilly_prates@hotmail.com.

2Graduate Program in Teaching, Language and Society; Group of Studies, Research and Extension in Education, Culture and Health, Universidade do Estado da Bahia, Guanambi (BA), Brazil. Email: rimussi@yahoo.com.br.

3Universidade Federal de Santa Catarina, Florianópolis (SC), Brazil. E-mail: edioluizpetroski@gmail.com.

4Universidade Estadual do Sudoeste da Bahia, Jequié (BA), Brazil. E-mail: hlrmunaro@uesb.edu.br.

5Group of Studies, Research and Extension in Education, Culture and Health, University of Brasília, Brasília (DF), Brazil. E-mail: aninha_m_godoy@hotmail.com.


ABSTRACT

The aim of the study was to estimate the prevalence of chronic spinal problems or back pain (CSP/BP) and the sociodemographic factors, the lifestyle, the chronic diseases associated with quilombola adults. We carried out a population, sectional, epidemiological study with a representative sample from a Northeastern state. We collected data by interviewing participants using a standardized form. Statistical analysis comprised robust Poisson regression, prevalence ratios, confidence interval (95%), and significance level lower than 5%. The prevalence of CSP/BP was of 50.5% (95% CI: 47.1: 53.9), independently associated with age, sleep quality, self-reported health, motor disabilities, and work-related musculoskeletal disorders. We observed higher exposure to CSP/BP among quilombolas aged >40 years, with poor sleep quality and poor self-reported health diagnosed with work-related musculoskeletal disorders (WMSD) and motor disabilities.

Keywords African Continental Ancestry Group; Spine; Health Surveys

RESUMO

O objetivo deste estudo foi estimar a prevalência de problemas crônicos de coluna ou dor nas costas (PCC/DC), os fatores sociodemográficos e de estilo de vida e as doenças crônicas associadas em adultos quilombolas. Foi realizado estudo epidemiológico, populacional e seccional, com amostra representativa de uma região de um estado nordestino. Os dados foram coletados por meio de entrevista com formulário padronizado. A análise estatística consistiu na regressão de Poisson robusta, com cálculo das razões de prevalência, intervalo de confiança (95%) e nível de significância inferior a 5%. A prevalência de PCC/DC foi de 50,5% (intervalo de confiança - IC95%: 47,1:53,9), independentemente associada ao grupo etário, à qualidade do sono, à saúde autorreferida, à deficiência locomotora e aos distúrbios osteomusculares relacionados ao trabalho (Dort). Houve maior probabilidade de exposição aos PCC/DC para os quilombolas com idade >40 anos, má qualidade do sono, pior saúde autorreferida, diagnóstico de Dort e deficiência locomotora.

Descritores Grupo com Ancestrais do Continente Africano; Coluna Vertebral; Inquéritos Epidemiológicos

RESUMEN

El presente estudio buscó verificar la prevalencia de Problemas Crónicos de Columna o Dolor de Espalda (PCC/DE) y los factores sociodemográficos, de estilo de vida y las enfermedades crónicas asociadas en adultos quilombolas. Se realizó un estudio epidemiológico, poblacional y seccional, con una muestra representativa de una región del Nordeste brasileño. Los datos se recolectaron por medio de una entrevista con formulario estandarizado. El análisis estadístico consistió en la regresión de Poisson robusta, con cálculo de las razones de prevalencia, el intervalo de confianza (95%) y el nivel de significancia inferior al 5%. La prevalencia de PCC/DE fue del 50,5% (intervalo de confianza - IC95%: 47,1:53,9), independientemente asociada al grupo de edad, la calidad del sueño, la salud autorreferida, la deficiencia locomotora y los disturbios osteomusculares relacionados al trabajo (Dort). Se observó que hubo una mayor probabilidad de exposición a los PCC/DE en los quilombolas con edad >40 años, mala calidad del sueño, peor salud autorreferida, diagnóstico de Dort y deficiencia locomotora.

Palabras clave Grupo de Ascendencia Continental Africana; Columna Vertebral; Encuestas Epidemiológicas

INTRODUCTION

The spine is one of the structures of the human body of greater locomotor demand, which can affect posture, and lead to musculoskeletal problems and pain1. Chronic spinal problems/back pain (CSP/DC) comprise several morbidities. Neck, chest and sciatica pains, intervertebral disc disorders, spondyloses, back pain and radiculopathy are the most common ones2.

These morbidities also represent the most prevalent health problems3. A fifth of Brazilian adults show CSP/DC2, affecting around 15% and 20% of the lifetime of individuals3, being the second most prevalent chronic disease in this population4),(5. Despite not being severe, such problems affect individuals’ health conditions negatively3.

The use of health services by sick people increased proportionally to the sociodemographic characteristics of patients6. We estimate that around 70% to 85% of the population will experience an episode of BP during their lifetime7. However, there are still disagreements on the prevalence of CSP/BP and its predisposing factors2),(7)-(9, especially concerning ethnic and racial characteristics.

Considering the continental dimensions and socio-demographic, economic and racial-ethinic differences of Brazil, there is need for further screening actions to be taken in the different regions and populations to proper address different epidemiological frameworks. Thus, ethnic and racial health indicators show it is even worse for black people10. As quilombolas descend from black slaves who worked with agriculture11, socio-economic and ethnic-racial issues reinforce health inequalities12.

Given the lack of information on the life and health conditions of black populations, which hinders the understanding of the health-disease process regarding CSP/BP and its predisposing factors, this study aims at estimating the prevalence of CSP/BP, the sociodemographic factors, the lifestyle and the chronic diseases associated with quilombola adults.

METHODOLOGY

This is a cross-sectional and descriptive study with analytical aspects, based on primary data derived from a population-based cross-sectional epidemiological survey named: “Perfil epidemiológico dos quilombolas baianos”, authorized by the Human Research Ethics Committee of the Universidade do Estado da Bahia, under protocol no. 1,386,019/2016, Certificate of Ethical Assessment (CAAE) No. 49955715.6.0000.0057.

The empirical field was the geographical microregion of Guanambi, Bahia, with 42 quilombos and contemporary rural descendants13 by the year 2016, divided into ten municipalities. Given the unavailability of previous official information on the number of inhabitants of these quilombos, population was estimated considering 80 families per quilombo14, with two adults (>18 years) per household in each community, totaling 6,720 adults.

The sample calculation comprised finite population correction, unknown prevalence for the outcome (50%), confidence interval of 95%, tolerable sampling error of five percentage points, design effect of 1.5 to cluster sampling, 30% additional to refusals and 20% for losses and misunderstandings, determining a sample of 818 subjects; more information on the sampling and methodological procedures can be found in previous studies15.

Those with cognitive or communicative disabilities were excluded from the interviews. Inpatients, amputated people and people in plaster, pregnant women and mothers with kids of less than six months were excluded from the anthropometric measurements. When patients did not completed a measurement, test or did not reply to any of the questions of the interview, we considered it as a loss.

The CSP/BK is the dependent variable determined from the response (“yes” or “no”) to the following question: “Do you have a chronic spinal problem, such as chronic back or neck pain, low back and sciatica pain, vertebrae or disk problems?”, which went through the validation process for application in the quilombola population12.

Socio-demographic variables are: sex (female, male), age group (<40 years, >40 years), schooling (<5 years, >5 years) and working hours per week (<44 hours/week, >44 hours/week).

Lifestyle (as a validated instrument of quilombola adults)12: general physical activity (those with >150 min per week were considered active and those with <150 min per week were considered insufficiently active), sedentary behavior (hours watching TV a day, >3 a day representing the presence of sedentary behavior) and self-reported quality of sleep (“very good” and “good” grouped into “good quality”; “regular”; and “poor” and “very poor” grouped into “bad quality”.

Self-reported health perception (“very good” and “good” grouped in positive; “regular”; and “poor” and “very poor” in negative), self-reported arthritis/rheumatism (“yes” or “no”), self-reported motor disability (“yes” or “no”), work-related musculoskeletal disorders (WMSDs)-(“yes” or “no”) and obesity (>30% body fat for women and >25% for men)16.

Measurements of fat percentage, determined by a bioimpedance validated scale (Omron hbf-514c, with capacity of 150 kg and 0.1% accuracy)17, occurred during the morning, before breakfast, in duplicate to ensure accuracy, or even three times in case of difference between the first two measurements, thus analyzing it from the median. Before that, we verified alcohol, caffeine and intense physical activity abstinence in the last 24 hours. The participants were told to remove metal objects and to remain at rest for five minutes before the tests.

To analyze the association of predictors with CSP/BK prevalence ratios (PR) were estimated from Poisson regression with robust variance. After verifying crude prevalence ratios, those with p-value <0.20 were considered for multiple analysis. The variables with p-value <0.05 in the saturated model were defined as associated with the outcome. The magnitudes of association were estimated by the 95% confidence interval (95%CI). All analyses were performed in the program SPSS Statistics, 22.0 version.

RESULTS

The CSP/BK was prevalent in 50.5% (95%CI: 47.1:53.9) of quilombolas, the absence of response rate was of 3% (26 losses). Age ranged from 18 to 92 years with median of 45. Most of them referred to themselves as black (86.5%) Women predominated 61.2%, 95%CI: 57.9:64.5). Table 1 presents the other characteristics of this population.

Table 1 Characteristics of quilombolas. Bahia, Brazil, 2016 (n=850) 

Sex
Female 61.2% (520)
Male 38.8% (330)
Age group
<40 years 42.1% (358)
>40 years 57.9% (492)
Race-skin color
Blacks 86.6% (716)
Others 13.4% (111)
Schooling
>5 years 41.5% (321)
<5 years 58.5% (453)
Working hours per week
<44 hours/week 73.8% (363)
>44 hours/week 26.2% (129)
Sleep quality
Good 65.7% (541)
Regular 22.7% (187)
Poor 11.5% (95)
General physical activity
>150 min 78.1% (650)
<150 min 21.9% (182)
Sedentary behavior
>3 hours/day 77.2% (578)
<3 hours/day 22.8% (171)
Self-reported health
Positive 48.9% (404)
Regular 41.6% (344)
Negative 9.6% (79)
Arthritis/Rheumatism
Yes 13.0% (107)
No 87.0% (718)
Dort
Yes 10.0% (82)
No 90.0% (740)
Locomotor disability
Yes 21.3% (176)
No 78.7% (649)
% fat
Obese 63.0% (513)
Not obese 37.0% (301)

Crude analysis (Table 2) showed higher prevalence of CSP/BP (p<0,05) among those aged >40 years, with <5 years of schooling, regular or poor quality of sleep, self-reported health as regular or negative, and diagnosed with arthritis and/or dort, and motor disability.

Table 2 PR of chronic spinal problem and its 95% confidence intervals (95%CI) according to socio-demographic, lifestyle and health condition variables. Bahia, Brazil, 2016 (n=850) 

VARIABLES PR (95%) p-value1 PR (95%) p-value2
Sex
Male 1 1
Female 1.144 (0.991:1.321) 0.067 1.174 (0.997:1.383) 0.054
Age group
<40 years 1 1
>40 years 1.951 (1.652:2.303) <0.001 1.410 (1.155:1.722) 0.001
Schooling
>5 years 1 1
<5 years 1.455 (1.244:1.702) <0.001 1.113 (0.943:1.313) 0.205
Work
<44 hours/week 1
>44 hours/week 1.047 (0.858:1.278) 0.653
Sleep quality
Good quality 1 1
Regular 1.364 (1.171:1.589) <0.001 1.125 (0.971:1.303) 0.116
Poor 1.669 (1.427:1.952) <0.001 1.266 (1.061:1.509) 0.009
Physical activity
>150 min 1 1
<150 min 1.187 (0.989:1.425) 0.066 1.193 (0.991:1.435) 0.062
Sedentary behavior
<3 hours/day 1
>3 hours/day 1.087 (0.855:1.383) 0.494
Self-reported health
Positive 1 1
Regular 1.627 (1.392:1.902) <0.001 1.424 (1.210:1.675) <0.001
Negative 2.290 (1.948:2.693) <0.001 1.552 (1.281:1.879) <0.001
Arthritis/Rheumatism
No 1 1
Yes 1.695 (1.494:1.924) <0.001 1.097 (0.953:1.264) 0.198
Dort
No 1 1
Yes 1.891 (1.690:2.117) <0.001 1.509 (1.314:1.733) <0,001
Locomotor disability
No 1 1
Yes 1.737 (1.539:1.961) <0.001 1.294 (1.129:1.485) <0.001
% fat
Not obese 1 1
Obese 1.133 (0.979:1.311) 0.095 0.944 (0.797:1.119) 0.508

PR: Prevalence ratio; 95%CI: confidence interval of 95%;1: p-value of crude analysis; 2: p-value of saturation analysis.

In multiple analysis (Table 2), after adjusting the variables included in the final model (p<0.20), the ones that remained independently associated with CSP/BP were: age group, quality of sleep, self-reported health, Dort diagnosis, and motor disability. Therefore, quilombolas aged 40 years showed a probability 41% higher to have CSP/BP. Similarly to those who reported having poor sleep quality, poor health conditions, a diagnosis of Dort and motor disabilities had 27%, 55%, 51% and 29% higher chances of achieving the investigated outcome.

DISCUSSION

The main findings of this study indicate that more than half of quilombola adults presented CSP/BK significantly associated with age group, sleep quality, self-reported health, diagnosis of Dort and motor disabilities. There is a chance of this being the first study analyzing a presentative sample of quilombola population in this region of the Brazilian state.

The CSP/BP decrease physical capacity and social contact, increase stress and anxiety, labour and financial problems, besides representing losses in treatment costing, sick pay and disability retirement3),(7, generating personal, social and economic problems.

The prevalence of CSP/BP in this study is higher than the 18.5% found for the Brazilian population2 and the 39.3% for quilombolas of a city of Bahia8. This high prevalence of CSP/BP in quilombolas may stem from early initiation in jobs that require high physical effort since childhood, a time when the skeletal structure is still under development18.

This analysis corroborates with other populational studies as it shows higher prevalence of CSP/BP among older patients2),(8, even after sex stratification7. It is known that aging leads to functional and motor changes in the musculoskeletal system, changing individual’s anatomical structure and motor performance19, negatively affecting flexibility and consequently increasing articulation problems20. Hence, the aging process requires better monitoring of access and use of health services by people with chronic non-communicable diseases (NCD), for the adequate planning of emergent demands6.

Sleep is essential in the life of human beings. There is a strong association between sleep disturbances and various diseases, given the intensification of musculoskeletal tensions. Which allows us to understand the association between the CSP/BP and the poor quality of sleep in quilombola adults, since this condition triggers negative organic symptoms of physical and/or cognitive origin, such as pains that hinder daily life activities.

As found in quilombolas, a representative study in Brazilian adults7 and a survey with predominantly caucasian population also observed association between worse self-reported health and BP9. This situation recognizes the interrelation between the presence of diseases with worse self-reported health, and that the negative perception of health increases in parallel with multimorbidity5.

The excessive use of the musculoskeletal system caused by repetitive movements and the continuous use of muscles or muscle groups, does not allow their full recovery, which causes Dort23. National survey on Brazilian adults also identified association between the CSP/BP and Dort2, which corroborates with our findings. This association is particularly worrisome given the possibility of worsening the vulnerability among the affected individuals and their families considering the socioeconomic demand for treatments(24), mainly in those with multimorbidities6.

We found no studies on the association between motor disability and CSP/BP. However, recognizing chronic pain as a frequent morbidity and functional disability condition(25) can explain the association identified in this study with quilombolas.

NCD’s are known for having multiple aetiology, many risk factors and long periods of latency, prolonged course, non-infectious origin and for its association with disabilities and functional disabilities.

One of the limitations of this study was the possibility of superestimating the prevalence of the investigated outcome, as issues such as participants’ perception and the access to health services may interfere in morbidity2. Another limitation of our study was inherent to its cross-sectional character, which did not allow us to establish a relation between exposure and outcome. However, studies with this design are robust tools that allow us to describe the life and health conditions in specific populations(26).

As its main advantage, this study brought relevant information regarding the postural health situation of a quilombola population who lived in a wide geographical region distant from economic and population centers of Bahia, thus being generally neglected by health services and academics. Population surveys, as the one presented, contribute to the public health policies setting based on the demands of the profile of participants(26).

CONCLUSION

The results indicate a high prevalence of CSP/BP in the participant quilombola population strongly associated with lifestyle and modifiable health (quality of sleep, self-reported health and Dort). This way, implementing strategies that consider the specific demands of the quilombola population will allow us to better prevent the worsening of morbidities.

These findings reinforce the importance of screening CSP/BK, highly prevalent NCD, as an useful mechanism to support specific health policies for rural black population, possibly more exposed to the group of diseases under study. Thus, the training of health professionals in the region can positively impact the health care of quilombolas.

REFERENCES

1. Nunes FL, Teixeira LP, Lara S. Perfil postural de estudantes de escolas urbanas e rurais: um estudo comparativo. Rev Bras Ciênc Mov. 2017;25(1):90-8. [ Links ]

2. Oliveira MM, Andrade SSCA, Souza CAV, Ponte JN, Szwarcwald CL, Malta DC. Problema crônico de coluna e diagnóstico de distúrbios osteomusculares relacionados ao trabalho (Dort) autorreferidos no Brasil: pesquisa nacional de saúde, 2013.Epidemiol Serv Saúde. 2015;24(2):287-96. doi: 10.5123/S1679-49742015000200011 [ Links ]

3. Camargos MCS. Estimativas de expectativa de vida com doenças crônicas de coluna no Brasil. Ciênc Saúde Coletiva. 2014;19(6):1803-11 doi: 10.1590/1413-81232014196.15812013 [ Links ]

4. Malta DC, Stopa SR, Szwarcwald CL, Gomes NL, Silva Junior JB, Reis AAC. A vigilância e o monitoramento das principais doenças crônicas não transmissíveis no Brasil: Pesquisa Nacional de Saúde, 2013.Rev Bras Epidemiol. 2015;18(2):3-16. doi: 10.1590/1980-5497201500060002 [ Links ]

5. Theme Filha MM, Souza Junior PRB, Damacena GN, Szwardcwald CL. Prevalência de doenças crônicas não transmissíveis e associação com autoavaliação de saúde: Pesquisa Nacional de Saúde, 2013.Rev Bras Epidemiol. 2015;18(2):83-96. doi: 10.1590/1980-5497201500060008 [ Links ]

6. Malta DC, Bernal DC, Lima MG, Araújo SSC, Silva MMA, Freitas MIF et al. Doenças crônicas não transmissíveis e a utilização de serviços de saúde: análise da Pesquisa Nacional de Saúde no Brasil. Rev Saúde Pública. 2017;51(1):4s. doi: 10.1590/s1518-8787.2017051000090 [ Links ]

7. Malta DC, Oliveira MM, Andrade SSCA, Caiaffa NT, Bernal RTI. Fatores associados à dor crônica na coluna em adultos no Brasil. Rev Saúde Pública. 2017;51(1):9s. doi: 10.1590/s1518-8787.2017051000052 [ Links ]

8. Santos LRCS, Assunção AA, Lima EP. Dor nas costas em adultos residentes em territórios quilombolas, Bahia. Rev Saúde Pública. 2014;48(5):750-7. doi: 10.1590/S0034-8910.2014048005317 [ Links ]

9. Ferreira GD, Silva MC, Rombaldi AJ, Wrege ED, Siqueira FV, Hallal PC. Prevalência de dor nas costas e fatores associados em adultos do sul do Brasil: estudo de base populacional. Rev Bras Fisioter. 2011;15(1):31-6. doi: 10.1590/S1413-35552011005000001 [ Links ]

10. Coimbra Jr CEA, Santos RV. Saúde, minorias e desigualdade; algumas teias de inter-relações com ênfase nos povos indígenas no Brasil. Ciênc Saúde Coletiva. 2000;5(1):125-32. doi: 10.1590/S1413-81232000000100011 [ Links ]

11. Secretaria de Políticas de Promoção da Igualdade Racial (SEPPIR). Guia de políticas públicas para comunidades quilombolas, 2013 [cited 2019 Jan 30]. Available from: https://goo.gl/5WCpEMLinks ]

12. Bezerra VM, Medeiros DS, Gomes KO, Souzas R, Gatti L, Steffens AP et al. Inquérito de saúde em comunidades quilombolas de Vitória da Conquista, Bahia, Brasil (Projeto COMQUISTA): aspectos metodológicos e análise descritiva. Ciênc Saúde Coletiva. 2014;19(6):1835-47. doi: 10.1590/1413-81232014196.01992013 [ Links ]

13. Fundação Palmares, 2016. [cited 2016 Nov 24]. Available from: https://goo.gl/7gQ3BfLinks ]

14. Secretaria de Políticas de Promoção da Igualdade Racial da Presidência da República (SEPPIR). Comunidades Quilombolas Brasileiras: Regularização Fundiária e Políticas Públicas. Brasília, 2010 [cited: 2019 Jan 30]. Available from: https://goo.gl/emQGwALinks ]

15. Mussi RFF, Petroski EL. Síndrome metabólica e fatores associados em quilombolas baianos. Ciênc Saúde Coletiva. 2017 [cited 2019 Jan 30]. Available from: https://goo.gl/c76c8fLinks ]

16. US Department of Health and Human Services, National Institutes of Health. Understanding adult obesity. Bethesda: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); 2008 [cited 2016 Nov 24]. Available from: https://goo.gl/GMbMZfLinks ]

17. Bosy-Westphal A, Later W, Hitze B, Sato T, Kossel E, Gluer CC et al. Accuracy of bioelectrical impedance consumer devices for measurement of body composition in comparison to whole body magnetic resonance imaging and dual X-ray absorptiometry. Obes Facts. 2008;1(6):319-24. doi: 10.1159/000176061 [ Links ]

18. Rempel C, Haetinger C, Sehnem E. Reflexões de idosos sobre as relações entre o trabalho rural, problemas de coluna e postura corporal. Estud Soc Agric. 2013;21(2):289-307. [ Links ]

19. Lahr SLN, Ugrinowitsch H, Santos LLP, Andrade AGP, Benda RNl. Efeitos do envelhecimento e da base de suporte no controle postural. Rev Bras Educ Fís Esp. 2017;31(1):83-90. doi: 10.11606/1807-5509201700010083 [ Links ]

20. Mussi RFF, Teixeira EP, Figueiredo ACMG. Problema/dor articular e atividade física de tempo livre em Quilombo Baiano, Brasil. Rev Ciênc Méd Biol. 2016;15(1):68-72. doi: 10.9771/cmbio.v15i1.13297 [ Links ]

21. Corrêa K, Ceolim MF. Qualidade do sono em pacientes idosos com patologias vasculares periféricas. Rev Esc Enferm. USP. 2008;42(1):12-8. doi: 10.1590/S0080-62342008000100002 [ Links ]

22. Costa SV, Ceolim MF. Fatores que interferem na qualidade do sono de pacientes internados. Rev Esc Enferm USP. 2013;47(1):46-52. doi: 10.1590/S0080-62342013000100006 [ Links ]

23. Merlo ARC, Jacques MGC, Hoefel MGL. Trabalho de grupo com portadores de LER/Dort: relato de experiência. Psicol Reflex Crit. 2001;14(1):253-8. doi: 10.1590/S0102-79722001000100021 [ Links ]

Finance source: Nothing to declare

Approved by the Research Ethics Committee of UNEB: Protocol 49955715.6.0000.0057.

Received: July 21, 2018; Accepted: January 10, 2019

Corresponding address: Ricardo Franklin de Freitas Mussi - Universidade do Estado da Bahia, Av. Universitária Vanessa Cardona, s/n - Ipanema, Guanambi (BA), Brazil - Zip Code: 46430-000 - E-mail: rimussi@yahoo.com.br

Conflict of interest: Nothing to declare

Creative Commons License Este é um artigo publicado em acesso aberto sob uma licença Creative Commons