Multivariate stepwise logistic and linear regression analyses investigated the independent contribution of potential predictors to the following primary outcomes of interest: knowledge about the main modes of transmission (animal-to-animal and animal-to-human) and the animals classified as common vehicles (poultry and birds) for avian influenza (model 1); knowledge that wash hands with soap before and after touching raw poultry meat and use of gloves is a hygienic practices to avoid spreading of the avian influenza virus through food (model 2); wash hands with soap before and after touching raw poultry meat and use of gloves (model 3); perception of risk of contraction avian influenza for him/her (model 4). For the purposes of analysis, the outcome variables originally consisting of multiple categories in the logistic analysis were collapsed into two levels. In Model 1, respondents were divided into those who knew the main modes of transmission (animal-to-animal and animal-to-human) and the animals classified as common vehicles (poultry and birds) for avian influenza versus all others; in Model 2, those who knew that wash hands with soap before and after touching raw poultry meat and use of gloves is a hygienic practices to avoid spreading of the avian influenza virus through food versus all others; in Model 3, those that wash hands with soap before and after touching raw poultry meat and use gloves versus all others. In all models the following independent explanatory variables were included: age, gender, marital status, educational level, number of children, employment status, health professionals and reading scientific journals as sources of information, and need of additional information. Others independent explanatory variables were also included in the different models: perception of risk of contraction avian influenza (models 1-3); knowledge about the modes of transmission of avian influenza (models 2 and 3); correct definition of avian influenza and know that avian influenza could be transmitted by eating and touching raw eggs and poultry foods (model 4); knowledge that wash their hands with soap before and after touching raw poultry meat and use of gloves is a hygienic practices to avoid spreading of the avian influenza virus through food (model 3). Before testing multivariable logistic regression models assessing predictors of the outcomes of interest, we examined correlations to assess collinearity among the independent variables and bivariate relations between the independent variables and the dependent variable. The criterion to be met before any independent variable was considered for entry into an initial multivariable logistic regression model was a p-value ≤ 0.25 obtained for each outcome variable in the univari-ate analysis and noncollinear with other predictors. Furthermore, the significance level for variables entering the logistic regression models was set at 0.2 and for removing from the model at 0.4. Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated in the model for the independent variables. When building linear regression model, we have first included only one possible variable at a time. Then, using the variables that were significant at p-value ≤ 0.25, we constructed a stepwise multivariate linear regression model and the significance level for variables entry the model was set at 0.2 and for removal at 0.4. Statistical significance level was defined as a two-tailed p-value ≤ 0.05. Stata version 8.1 software program was used for all statistical analyses [14] .