Prevalência de dor crônica em uma Unidade Básica de Saúde de cidade de médio porte * Prevalence of chronic pain in a Basic Health Unit of a middle-sized city

JUSTIFICATIVA E OBJETIVOS: A dor é um fenômeno multifatorial e um dos sintomas mais frequente nas consultas médicas. O objetivo deste estudo foi avaliar a prevalência de dor crônica nos usuários de uma Unidade Básica de Saúde (UBS) na cidade de Santa Maria, RS. MÉTODO: Estudo de caráter transversal em que foram avaliados indivíduos de ambos os sexos, maiores de 18 anos que se encontravam na sala de espera da UBS. Dados de identificação, questionário genérico de qualidade de vida (SF-12), escala de capacidade funcional em pacientes com dor crônica e a escala analógica visual (EAV) foram aplicados. RESULTADOS: 37,8% dos indivíduos entrevistados possuíam dor crônica, a média de idade foi de 46,3 ± 16,4 anos, com predominância feminina (87%). Nos indivíduos portadores de dor crônica a intensidade da dor, avaliada pela EAV foi de 7,38 ± 2,16. CONCLUSÃO: Apesar da pequena população do estudo, é importante traçar estratégias preventivas visando o bem estar e a qualidade de vida dos pacientes. Descritores: Atenção primária a saúde, Dor crônica, Qualidade de vida.


INTRODUCTION
Pain has been a major human concern since the dawn of humanity.It is a red flag informing people about some biological change.It is a multifactorial phenomenon where tissue injury, emotional, socio-cultural and environmental aspects unify them 1,2 .Its manifestation is different and unique for each individual because each one has an individual perception about pain.In addition, pain is associated to physical and psychic factors 3 .Pain is a symptom and one of the most frequent reasons for looking for medical aid 4 .It is estimated than 80% of the world population look for the health system due to this morbidity 5 .In Brazil, it is estimated that chronic pain affects between 30% and 40% of the population and is the primary reason for absenteeism, medical leaves, early retirement, labor indemnities and low productivity, being considered a public health problem [6][7][8] .In January 2000, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) has published a standard describing pain as the fifth vital sign.So, it should always be evaluated and recorded together with other vital signs so that necessary adjustments are made to the treatment.Pain complaint should always be valued and respected due to the discomfort it brings 9,10 .Pain management policy, be it with its own control, be it by providing palliative care, is a major example of universality and transversality of interdisciplinary activities in the public health area.Assistance to painful patients is complex, requiring both knowledge and skill from the assistance team to adequately notice and manage pain 11 So, pain control is an imperative public health practice, especially in basic health care, due to the demand for health services and to the unfavorable social impact on quality of life of chronic pain patients 12 .It is important to stress that the lack of adequate diagnosis and treatment during the acute phase may favor pain chronicity and worsen clinical presentation 13 .So, this study aimed at investigating the prevalence of chronic pain and its impact on quality of life of users of a basic health unit.

METHOD
This is a transversal study focused on users of the Family Health Strategy Dr. Roberto Binato, in the city of Santa Maria -RS.Its coverage area is a population of approximately 13 thousand inhabitants.We have interviewed individuals who were in the waiting room for medical or dental assistance.Individuals of both genders, with more than 18 years of age were included, and pregnant women, people with neuropsychiatric diseases and neoplasias were excluded.All participants have signed the free and informed consent term (FICT).Our research has investigated the prevalence of chronic pain in these users, having as tools the personal data questionnaire, the generic quality of life questionnaire (SF-12), the functional capacity scale for chronic pain patients and the visual analog scale (VAS).SPSS 15.0 software was used for data analysis.Symmetric data were presented in mean and standard deviation.Asymmetric data were expressed in median and percentiles (p25 and p75).This study was approved by the Research Ethics Committee, Franciscan University Center under n.210.2011.2.

RESULTS
Participated in this study 45 individuals..Table 2 shows general data about quality of life and prevalence of pain of chronic pain respondents.

DISCUSSION
Pain is a symptom frequently referred by patients in primary health care.Pain is an alert symptom, common to several diseases with negative impact in health-related quality of life.So, diagnosis and treatment in primary health care is important, so that pain does not reach more complex health care levels 15 .
Even being a direct expression of departure from a healthy condition, pain and functional incapacity are overlooked elements by the basic health care in Brazil since they are not specifically recorded by basic health units (BHU).This is in contrast with one responsibility of the basic care strategy in Brazil, which is to maintain a proactive position when facing population's healthdisease problems 16 .
In our study, 37.8% of respondents had chronic pain.
Mean age was 46.3 ± 16.4, with female predominance (87%).In chronic pain individuals, pain intensity by VAS was 7.38 ± 2.16.The high VAS score indicates relatively severe pain and the large number of individuals with this daily complaint may orient basic care services to this part of the population, since there is a strong association between pain and low working capacity 17 .Pain incidence is increasing due to new lifestyles, longer life expectancy and environmental changes.In addition to generating physical and emotional stress, it is the reason for high economic and social expenditures for society.Data from the National Institute of Social Security (INSS), from 2007, show that 20% of benefits granted due to medical leave were aimed at chronic pain patients 18 A study carried out from January 2004 to January 2008 has shown that the mean cost for a chronic pain patient is R$ 127.00 per month (varying between R$ 5.00 and R$ 780.00) being these amounts spent only with medications 19 .A study was carried out in the city of Sorocaba with chronic pain patients treated by the three health care levels and has observed a major chronic pain demand in basic health care units 20 .
Our study has evaluated quality of life by the SF-12 questionnaire.This is a summarized version of the SF-36 questionnaire with 12 items encompassing eight SF-36 dimensions.It has two domain areas: physical health and mental health.Respondents have shown values below the cutoff point for such questionnaire (42.6 ± 13.2) suggesting a poorer quality of physical life as compared to individuals without chronic pain (p < 0.05).However, there has been no significant difference in mental health.
Maybe with a larger sample this could have been shown.
Added to the quality of life questionnaire, we have also evaluated functional capacity of chronic pain patients.This scale has three dimensions: pain intensity, interference with functional and emotional activities.
The population evaluated presented moderate pain (5.6 ± 0.47) and interference both with functional and emotional activities (3.48 ± 0.21 and 3.64 ± 0.18, respectively).A study 21 on the impact of chronic pain on quality of life has shown that it has a negative impact on quality of life of up to two thirds of patients, especially on the ability to exercise, to practice sports, to perform daily life activities, as well as to perform labor activities.
A different study 22 evaluating functional capacity by the Older American Resources and Services (OARS) scale, validated for the Portuguese language, with 111 elderly people with chronic pain and living in the area of a BHU in the city of Londrina, PR, has observed interference, especially with sleep, mood and leisure, that is, chronic pain has negative impact on patients' functional capacity, especially to perform daily activities, and may limit or even lead to functional incapacity.In spite of the small sample size, it is important to stress that preventive strategic measures are needed to promote well being and quality of life of chronic pain patients.

CONCLUSION
Chronic pain directly affects function and quality of life of patients and, due to its high prevalence, there is the need for further BHU professionals attention to treat it efficiently.

Table 2 -
Data related to pain, quality of life and functional capacity of chronic pain patients.
*p < 0.05 versus SF-12 in individuals with no chronic pain.