title: Prevalence, characteristics, and factors associated with chronic pain with and without neuropathic characteristics in São Luís, Brazil.
abstract: BACKGROUND
  Chronic pain (CP) with and without neuropathic characteristics is a public health problem. This is the first population-based study in South America, and the third in the world, to use the Douleur Neuropathique 4 Questions (DN4) tool in epidemiologic studies.
  
  
  OBJECTIVE
  The objectives were to estimate the prevalence and associated factors of CP with and without neuropathic characteristics in São Luís, Brazil.
  
  
  METHODS
  We surveyed 1597 people. The DN4 questionnaire was applied. Poisson regression was used to analyze the risk factors.
  
  
  RESULTS
  The prevalence of CP was 42%, and 10% had CP with neuropathic characteristics (CPNC). The results showed that female sex and age ≥30 years were associated with an increased prevalence of CP (P<0.001) and education ≥12 years with a reduction in the prevalence of CP. The sensations listed in the DN4 were more common in people with CPNC and most frequent were pins and needles (87.9%). The cephalic region (36%) and limbs (51%) were the locations most affected. Most respondents felt pain between six months and four years (51.6%), with daily frequency (45%). Pain intensity, the impediments caused by pain, and sadness were more prevalent in people who had CPNC (P<0.001). Health status was regular for most, 50.9% did not know the cause of their pain, 64.1% used drugs, and only 7% had consulted with a pain specialist. Dissatisfaction with treatment was reported by 55%.
  
  
  CONCLUSIONS
  CP with and without neuropathic characteristics is a public health problem in Brazil, with high prevalence and great influence on people's daily lives.
authors.affiliation: Pain Research Group, Federal University of Maranhão, São Luís, Brazil. enfermeira_erica@yahoo.com.br
authors.forename: Erica Brandão
authors.initials: EB
authors.lastname: de Moraes Vieira
authors.forename: João Batista Santos
authors.initials: JB
authors.lastname: Garcia
authors.forename: Antônio Augusto Moura
authors.initials: AA
authors.lastname: da Silva
authors.forename: Rayanne Luíza Tajra
authors.initials: RL
authors.lastname: Mualem Araújo
authors.forename: Ricardo Clayton Silva
authors.initials: RC
authors.lastname: Jansen
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D001938:Brazil / Q000453:epidemiology; D059350:Chronic Pain / Q000150:complications / Q000453:epidemiology* / Q000523:psychology; D003430:Cross-Sectional Studies; D003625:Data Collection; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000453:epidemiology; D010147:Pain Measurement / Q000379:methods; D010523:Peripheral Nervous System Diseases / Q000473:pathology; D011153:Population; D012044:Regression Analysis; D012307:Risk Factors; D018401:Sample Size; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D055815:Young Adult