title: Influence of the Socio-Economic Context on Self-Reported Gingival Bleeding in Individuals of Ethnic Minority Groups: A Multilevel Analysis.
abstract: BACKGROUND
  To evaluate the influence of the socio-economic context on self-reported gingival bleeding (SRGB) in individuals of ethnic minority groups (IEG).
  
  
  METHODS
  Data from the 2007 National Public Health Survey in Colombia were collected. A multiple-stage stratified sampling was used. Data from 34.843 subjects were collected through interviews. The influence of socio-economic factors on SRGB in IEG was investigated with logistic and multilevel regression analyses.
  
  
  RESULTS
  Out of 34.843 subjects studied, a total of 6.440 individuals were members of ethnic minority groups. SRGB was observed in approximately 5% of IEG. There was a significant difference between IEG and subjects of the rest of the sample (28.403 subjects) regarding SRGB, elementary and high school education, Gross Domestic Product (GDP), Human Development Index (HDI) and Unmet Basic Needs Index (UBNI) disfavouring IEG (P<0.05). The logistic model showed that SRGB was associated with IEG (P<0.001). This association persisted after controlling for confounders. A total of 33 Colombian states (level 2) and 6.440 members (level 1) of ethnic minority groups were included in the multilevel analisys; this model showed that the variance on SRGB was statistically significant at level 1 and 2. However, the variation at IEG level (35%) was smaller than the variation between states (65%) in the multilevel multivariate model.
  
  
  CONCLUSIONS
  SRGB was higher in IEG. Also, GDP, HDI and UBNI were unfavourable factors in the members of ethnic minority groups. Considering these detriment factors and the higher variation between states, this study suggests that socio-economic context affects significantly SRGB in IEG.
authors.affiliation: Titular Professor Universidad de Antioquia Biomedical Stomatology Research Group, Department of Periodontology, School of Dentistry, Universidad de Antioquia U de A, Medellín, Colombia. martin.ardila@udea.edu.co.
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Ardila
authors.forename: Annie Marcela
authors.initials: AM
authors.lastname: Vivares-Builes
authors.forename: Andrés A
authors.initials: AA
authors.lastname: Agudelo-Suárez
mesh_terms: D000328:Adult; D003105:Colombia / Q000453:epidemiology; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D005884:Gingival Hemorrhage / Q000208:ethnology*; D006306:Health Surveys; D006801:Humans; D008297:Male; D008913:Minority Groups / Q000706:statistics & numerical data; D055361:Multilevel Analysis; D057566:Self Report; D012959:Socioeconomic Factors